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Energy Auditor


Eric Gans
Certified Energy Auditor


Residential Comfort & Energy Efficiency

Tuesday, March 09 2021
Amazing Results! A Maryland Home Energy Audit Case Study

There are literally thousands of homeowners in Maryland that are a lot closer to having a more comfortable home than they ever could have imagined.

Let me explain...

This past March I did a BGE energy audit in Howard County for a really nice family that just moved back to Maryland from a warmer part of the country around the end of summer 2020.

They reported to me that their first winter here was brutal. 

Cold spots at every turn, drafts in areas they enjoyed to spend time and the basement has been all but abandoned, despite having a nice playroom and a video game console with surround sound.  But on the coldest days it was just too much.

Two Reasons this Audit Makes a Great Case Study

First, the family was pretty much in the dark all winter about what they could do about their issues.  They love the home and the location, but something seemed wrong and they really did not know where to turn for solutions.  The HVAC was running continuously and never caught up.

Here is the other thing too - they just came off of having a home inspection done when they bought the property. 

What I have observed from time to time is that a home inspection gives homebuyers a false sense of security, particuarly when it comes to insulation. 

The inspection is more in line with the old way of thinking about insulation...

I see pink stuff in the attic - all is good. 

The box gets checked and you, the end user, is puzzled by the drafts and looking at windows and doors for answers to why it is so cold.

But, as you will see, the inspector missed a few key things and did not give any guidance at the time that would assist the family in finding a swift solution.  So, instead, they spent the winter draped in blankets studying their window and door seals wondering if there was anything that could be done.

We cannot blame the inspector though.  Some of the key insulation concepts get lost on the best home inspectors.  It can get a little complicated.

The second thing that was fantastic about this scenario is that the BGE Home Performance with ENERGY STAR® program helped the family uncover their underlying issues and the incentives, available to all BGE and Pepco customers, paid for 70% of the cost in this case.

"The BGE Home Performance with Energy Star® Program will pay for 70% of the cost."

Sorry, that was worth repeating!

The part about all of this that gets my wheels spinning is how many other people are out there, enduring miserable winters, or hot summers for that matter, that could also benefit from this program in the exact same way.

This case study clearly demonstrates why an energy audit is such a critical assessment for a home to undergo. 

The same problems are happening in households everywhere in Maryland. 

Energy Audit - A Critical Home Assessment

An energy audit can illuminate comfort problems that would otherwise stay hidden in plain sight and this case study is a classic.

The Symptoms for this BGE Customer Case Study

-HVAC running all of the time
-Never really feel warm on the cold days
-Shockingly high energy bills
-Cold basement
-Drafty top floor
-Cold master bathroom
-Cold kids bedroom

I want to stop here and place a little emphasis on this list. 

I believe that this is where the disconnect exists for a customer that has these issues in their home and never gets an energy audit done.  

There is an expression that my dad would use - "if I had a nickel for every..."

If you add up all of my energy audits over the years, I would say that I would have fully completed roughly 1300 of them.  And, if I had a nickel for every customer that blamed their windows and doors - I would likely have 40 bucks (that is about 62% of the people if you don't wanna do the math).

The underlying message here is that if you have not gotten an energy audit because you think it is your windows and doors, then you might be surprised. 

Most people that have the audit done always seem quite enlightened by what is actually causing their problems.


The Case Study - Figuring Out the Root Cause

An energy audit is a process of gathering data points around your home.  The volume, square footage, foundation layout and type are all important to help you find the best solutions for making things better.

Sometimes, the first hour of an audit does not prove to be fruitful in terms of "opportunities" for improvements, or retrofits.  A well trained energy auditor never wants the cost of the project to outweigh the benefits.  An auditor is on the hunt for the low hanging fruit.

As an energy auditor, you can have some fun with this. 

It can be much like the game show Let's Make a Deal.  Every door you open to an attic or crawl space presents a unique set of circumstances that will either prove to be a great chance to move the comfort needle for the customer or it could be a dead end.

Now, this can also be kind of a slippery slope.  Great opportunities also come with a cost.  Meaning, if your home is stubbornly uncomfortable and the places that require insulation are under insulated and accessible that is fantastic because you can fix it!  But, it also means that you have to spend money to do so.

But, as mentioned, there are incredible incentives through BGE and Pepco available to help manage the cost.

Time to Investigate the Attic

This particular home has two sections of accessible attic space. One access point is in the hallway.

Attic investigation case study howard county maryland

I took a trip up through door number one to inspect the attic space.

BGE Energy Audit

The first sign upon poking my head up is that the attic floor is insufficiently insulated.  One thing I have learned through the years is that those with some of the biggest issues have rolled batt insulation in the attic as this home did. 

Read what John Krigger and Chris Dorsi say about fiberglass batt insulation in the book Residential Energy: Cost Saving and Comfort for Existing Buildings

"All of the common facings attached to fiberglass batts are air barriers and most are vapor barriers.  However, their effectiveness as an air barrier depends on nearly flawless installation."

Fiberglass batt insulation is almost always not installed to perfection.

Now, I can't be sure about what I am about to say, but this is where I believe most energy auditors stop.  They take a quick peak at the attic and draw every conclusion for that specific attic area without proper investigation.

I take pride in going the extra few steps and I find that is usually proves to be beneficial - for my customers.  The rule is if I don't really want to go over to that spot then chances are not too many people do and therefore there could be a problem there that nobody has ever seen.

attic investigation Maryland

When I got in the attic and made a 180 degree turn, I saw what appeared to be a knee wall that was missing insulation.  The area was in a tough to reach part of the attic.

I decided to go around the corner to see what was going on because it was not quite making sense to me.  As with anything that you do on the regular, patterns emerge and a more comprehensive understanding of what you are doing comes over time - aka: experience. 

Adding to my sense of curiosity was the fact that during my initial tour of the home, the customer had pointed out to me that some remodeling was done in the vicinity below before they bought the home. 

A good home energy auditor has to be a like a sponge, absorbing bits of information throughout the time at the home so it can all be pulled together to produce sound solutions.

uninsulated attic area discovery 

Then, once I was able to poke around the corner this is what I found.  A ten by ten area of un-insulated attic space hiding behind that wall. 

This is important for two reasons. 

Reason One - it speaks to the issues that they were experiencing on cold days.  Having insulation at the attic floor is the most important place to build the insulation boundary because the pressure is greatest.  

Hot air rises in a building and it wants to fly right out of the top and will if you let it.  Cracks and crevices are certainly big time issues for this, but because insulation slows the transfer of heat, the thin drywall alone is no match for the heat to escape at very high rates. 

Missing insulation is a big time issue. In an earlier article I wrote about how I examined the impact of an un-insulated three by six foot area in an approximate thousand square foot attic (2% if the area) equated to a 25% reduction in the overall R-value of the insulation in that particular attic.

Reason Two - it produces a larger incentive through the BGE Home Performance program.  Some of the rebate calculations are based on how much insulation an attic currently needs and when there is nothing, it pushes the incentive up. 

Missing the un-insulated area and modeling the home as if it did have insulation in that area would be cheating the customer.

My final mission while in this section of the attic was to determine if I could make passage to the other side of the home and I was able to confirm that I could not and had to use the second attic entrance.

BGE Energy Audit

Second entrance to the attic was located in the master bedroom closet.

Home Comfort Specialists

More of the same in the second attic area.

The verdict is in!  This attic needs to be air sealed and insulated.  Time to run the numbers!

How Does this Program Pay for 70% of the Cost?

In order to help you understand how this program works, I will share the exact numbers from this project and how it worked out so favorably for this customer and you can hopefully gleen information to compare to your own situation and see if you can benefit like the family in this scenario.

But, if you don't have all or any of these characteristics in your home, that does not mean you will not qualify for rebates or that an energy audit won't uncover some totally different issue for you that will find a way to make it well worth your while.

The Numbers

Prioritized List of Energy Efficient Improvements

Total Cost of Improvements: $9500.00
BGE Incentive for this Project: $6640.70

Total Ratio: 70% of the total cost

Financial Analysis

A financial analysis will indicate annual realizations and provide simple payback years. 

How many home improvement projects actually pay you back?

Summary of Proposed Improvements

Whole House Air Sealing

When receiving rebates through the BGE Home Performance Program with ENERGY STAR, the blower door test is an integral part of the overall incentive structure and it is tied in many ways to each individual item listed on the list of improvements.

For example, when treating the attic on this project, by far the largest component of the improvement plan, sealing must be done at the attic floor so that the insulation performs to the R-Value it is designed to meet. 

Basic Air Sealing

This is also a key to the whole house air sealing plan.  At the end the house is tested again for air leakage.  The overall leakage is reduced by the acceptable figure established by the program (10% minimum to qualify).

Rim Joist - Accessible

The top of the foundation wall in any home is leaky and needs to be sealed.  The question is how much of the area is unfinished and accessible to keep the cost vs. value in line.

Knee walls/Vertical Attic Walls/ Slope Transition Locations


Not all homes have knee walls so this section may or may not apply.  Knee walls are very difficult to visualize.  Photos can help.

Top photo: thermal image of the knee wall that is created by the transition from a sloped ceiling back to a flat 8' ceiling.

This image is taken at the exact same time the top thermal image was taken for point of reference.

This is a look at the missing insulation at the knee wall from the attic.

Attic Insulation - Sloped and Flat Areas

Once all of the "little" things around the attic and basement have been sealed and insulated and the attic floor areas have all been sealed, it is time to lay down the to speak.

Blown Cellulose Demo

Improvement Results

Getting a considerable rebate on a project around the home that you still have to come out of pocket some money for won't be worth it if the results are not there.

The great thing about the BGE Home Performance with ENERGY STAR program is that we measure the results at the end.  This is done in a few diferrent ways.

Visual Inspection

Once the work is done it is the responbility of the energy auditor assigned to perform the final test to check the work that was done.  If they were not on the job, this can be done by simply looking in the attic.  The blower door test will reveal if air sealing was not completed, but it is very difficult to look for air sealing once the insulation has been installed.

Blower Door Test

The Blower Door Test

When the blower door test is done at the audit the "test-in" measurement is recorded.  A portion of the incentive and the customer's long term savings and comfort is also tied to the blower door test and that is why it is so important to the overall job process and the BGE program.

Here are photos of the actual blower door test results for this case study.  The numbers look really good!

actual blower door test results

Air Flow at Test-In = 4949 Cubic Feet Per Minute

After Air Sealing

Air Flow at Test-Out = 3552 Cubic Feet Per Minute

28% Reduction


Customer Satisfaction - Measured Results

It is one thing to hit the mark on the numbers and achieve the goals when it comes to measuring the work that was performed.

Another part of a successful Home Performance with ENERGY STAR project is the customer's overall experience.  It certainly would be fantastic to have a more comfortable home with lower bills, but having a pleasant experience along the way should also play into things.

Based on a recent review by the customer on Google, it seems like we hit the mark on this one too!  Making this a successul project all the way around!

"Had a great experience with Eric and his team. Eric conducted our home energy audit taking time to point out and discuss the good and bad, answering all my questions. He also took care of the whole rebate process with the local utility. All phases of project completed in about 3 weeks. Easy and painless. Definitely recommend Eric and the Hometrust team!"

Read the Review Here

Need Advice on How to Do Something Like This?

If you are interested in making your home more comfortable and more efficient, give me a call.  We can discuss your situation and likely getting a BGE or Pepco Energy Audit is the way to go.  

Incentives through the program can be quite advantageous, particularly for those that know that they have to get this problem resolved once and for all. 

Furthermore, an energy audit can uncover other factors that can contribute to your specific issue as each home is different - even the same model across the street.

Give me a call!  I'd love to help you out!

energy audit maryland

Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.

Saturday, March 06 2021
Who's Gonna be Sweating Bullets this Summer; You? Or, Your Ducts?

Most homes nowadays have air ducts that condition the inside of our living spaces.  Ducts are largely responsible for keeping us warm in winter and cool in summer.

And, yet despite their importance, they are often overlooked.  

Aside from the obvious, like making sure ducts are connected, there are other nuances that must be understood to prevent other potential issues.  For example, leaky ducts in summer in the wrong location might lead to condensation resulting in water damage to ceilings or wood.

This article will examine summer condensation issues related to ducts that run outside of the "envelope".  This would include ducts that run through a garage (the focus of this post), crawl space, attic or cantilever also known as an overhang.

Watch the Four Part Process First - Then Learn How it Came About

Part 1 -The blank canvas.  A fully removed plaster ceiling including the removal of nails and screws.  The area beneath the ducts has been swept and protective platic has been installed to keep the area clean and neat for the customer once the project is completed.

Part 2 -Application of the spray foam on the different areas of the HVAC supply plenum.  During this portion of the video, the foam bonds to the duct and seals and insulates rapidly.

Part 3 -Removal of excess insulation after it has fully cured.  This is done in preparation for the drywall ceiling installation later in the week.

Part 4 -A look at the completed portion of the duct sealing and insulation project to get a feel for the final product.


Initially - I Was a Little Worried About this Project

According to my eventual customer, the garage ceiling insulation project had already been contracted to be done and when the chosen company showed up to do the work, they promptly turned around and said it was too much for them to handle.  That, in turn, prompted the customer to call me.

But, when I went out to take a look at the garage and all that was involved, it did not appear to be too much as far as I was concerned and I quickly got to assessing the situation for the best way to get it done!

Insulated Ducts Are Not Sealed Ducts

If you so dare to pop your head in the attic and you see that your ducts are insulated you cannot simply assume that everything is in good shape.  Ducts are metal casings that have seams and connection points.  Not all duct insulation is designed to seal the small air leakage around seams.

Older ducts in older homes like the ones in the garage example below were not made as precisely as they are today.  Some systems have slots and cracks from shifts that occur normally in a home. 

Additionally, houses go through changes and therefore the paths that the conditioned air takes have to be altered.

One example can be seen commonly when the central furnace/ air conditioner is replaced with a larger unit at the same time an addition is being put on a house.  The larger system is now being called upon to provide heating and cooling to the new living space. 

During this process, the existing ducts are "tapped" so that new ducts can be run to the addition. 

It is during these re-configurations where some of the largest gaps and cracks can be detected in the ducts.  Of course, the ones you can get to should and can be sealed, but the harder to reach leaks in the areas outside of the "envelope" are the ones that can be trouble.

Garage Ceiling Example

In this example, the home was built in 1958.  For a home built in 1958, it was likely cutting edge.  Living space over a two car garage with a design that included ducts running through the ceiling to service the space above.  In theory, it was practical, efficient and ahead of its time.

But, as each and every Maryland summer would introduce new hot, humid air into the garage it would find its way more and more into the the space between the garage ceiling and the floor to the living space above and as the central air conditioner was improved and likely the sized increased - the ducts began to form condensation.

Drip...drip...drip...and eventually the water actually blew right through the insulation that was installed when the home was built (can be seen in photo below).  Soon after, the plaster ceiling began to deteriorate and it had to be partially torn down.

sweating hvac duct damage in garage

Photo taken during initial inspection.  Partial demo had already begun.

A little more perspective of the area to be treated due to duct condensation issues during summer months.

energy audit maryland

Making the Most of the Situation

The driving force for this homeowner to take on this project was the duct condensation and the long term issues that can come about if they go untreated.  But, another reason for taking this on was due to the cold bedrooms above during the heating season. 

It was clear that the old insulation methods and the unsealed and un-insulated ducts running through the outside garage ceiling were contributing to the comfort issues. 

So, the plan included insulating the entire garage ceiling area as well.  The plaster ceiling was removed on day one, insulation was applied and the area was cleared of all trash and debris. 

Day 2 -----------

On day two the focus was on the main HVAC supply plenum (duct).  Final demo on the ceiling area that encapsulated the duct took place and preparations were made to seal the duct with two part spray foam.

Everything in the photo above is vintage 1958.  Sixty three years of water dripping down and creating a major blowout of the insulation, resulting in a damaged garage ceiling.

Special attention was going to be given to this area.  Since it was very close to where the HVAC air handler was located the pressure is greatest, therefore the more significant duct sweating that was taking place.

The Solution - Sealing and Insulating in One Shot

Two part spray foam is an effective treatment for a situation such as this one.  The removal of the ducts and the disruption and cost would outweigh the additional cost for the more expensive insulation material.  Getting behind to seal the tight spaces without having to remove flooring or support bracing is a great advantage of using spray foam.

You can see in the video the amazing capabilities of the liquid spray finding its way behind the ducts and moving to seal up the spaces that we know exist, but would have a tough time accessing otherwise.

Need Advice on How to Do Something Like This?

If you are interested in solving your duct condensation issue, give me a call.  We can discuss your situation and likely getting a BGE or Pepco Energy Audit is the way to go.  

Incentives through the program can be quite advantageous, particualarly for those that know that they have to get this problem resolved once and for all. 

Furthermore, an energy audit can uncover other factors that can contribute to condensation on ducts and the audit may uncover other solutions that render the need to insulate the ducts useless - while still solving the main issue.

Give me a call!  I'd love to help you out!

energy audit maryland

Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.

Sunday, January 10 2021

Did you know that when you participate in a Home Performance with ENERGY STAR project on your home that the results are actually measurable?

Is there any other home improvement project that when it is all said and done you can actually test and get immediate, unbiased results?  I can't think of any!

Let's take replacement windows as an example.  Often times windows are replaced around a home to improve comfort and reduce drafts.  But, results are typically subjective and more times than not there is a walk away feeling for both the homeowner and contractor that the windows did not really perform, but there is not much anyone can do now.

Home performance work on the other hand is instantly measurable and to take matters further, a home performance project actually focuses in on physical attributes of your home to really move the comfort needle in your favor. 

ANALOGY: If a jet is not able to take off from the runway, do you want the airline company mechanic to just fix a perceived issue and give it a whirl, or would you rather the technician employ diagnostic tools, real time onboard computer information and proper calculations to get the plane back in the air? 

Of course we all want the more informed approach to ensure our safe return to flight.

So how does this work in home performance you ask?  How can we be sure to target the right connections to the outside in a home so that we can get the results we want?

The blower door test!  A blower door test does two things...

First, it measures the leakage rate of your home.  It quantifies the amount of air that leaves through a large industrial sized fan that essentially "sucks" the air out of your home.

Physics demands that for every cubic foot of air that leaves an enclosure, a cubic foot of air will replace it through an crack, crevice, hole, connection, etc.

So as the fan pulls air out and creates a negative pressure fresh outside air is pulled in through all of the outside connection points in your home and as new air enters and flows through the house and back through the fan, a flow rate is achieved and recorded.  This is the starting number to then measure against after the work is completed.

The second benefit of a blower door test is that is allows the contractor and the homeowner to physically inspect the house while the test is running to discover the leakage points in a physical sense - rather than in a hypothetical sense.

This is very important for the average homeowner that has a thousand other things they would rather be doing and rather be learning about.

When a homeowner can actually participate and see that air leakage can be attributed to many other things before windows it has a profound effect. For every leaky window discovered at a blower door test there are five hundred examples of recessed lights that were much worse offenders.

One great example of a home that made huge gains in comfort, reduced drafts and overall energy usage was a home in which not a single window was replaced.  The results from the air leakage test were huge and the customer noticed a difference the first day.

Here are the blower door results as seen on the pressure and flow gauge (manometer).



The results show a 29% reduction in the leakage of this home.  This means that actual holes in the home's shell were proper sealed and the results have been measured through diagnostic testing.

So, what did we do to treat this house and make huge gains on reducing air leakage you ask?



Saturday, January 02 2021

Often times homeowners don't know what a Pepco energy audit is or how it can actually help.

For starters, a Pepco energy audit can help you avoid choosing the wrong solution to a problem around your home. An energy audit through Pepco is a good place to start a home improvement priority list. 

Take the important step of scheduling your Pepco energy audit as soon as you can!

Saturday, January 02 2021

Often times homeowners don't know what a BGE energy audit is or how it can actually help.

For starters, a BGE energy audit can help you avoid choosing the wrong solution to a problem. An energy audit through BGE is a good place to start a home improvement priority list. 

Take the important step of scheduling your BGE energy audit as soon as you can!

Friday, January 01 2021
The Blower Door Test - IECC Energy Code Maryland

IECC Energy Code Testing - Blower Door Test

This beautiful new construction house that was completed in summer 2020 located in New Windsor, MD went through one of it's final steps to pass the energy code in the state of Maryland. IECC Blower Door Test New Windsor Maryland

The blower door test, or air leakage test was performed in accordance with the International Energy Conservation Code (IECC). 

The air leakage code requires that a house test at equal to or less than three air changes per hour (3ACH). 

The test was conducted using the ASTM E1827 - single point method. 

The blower door test was conducted five times and each measurement was recorded and entered into the report. 

Each test result yielded an ACH number less than two so the house passed with flying colors. 

In Carroll County Maryland and many other counties across the country, it is important to consider the building envelope during each construction phase so that your house is sealed properly and it can also easily pass the test. 

Tighter houses use less energy and are more comfortable.  In a tighter house you control the home's "breathing" rather than letting your energy dollars escape through the  various holes to the outside around a typical residential building's shell.










General Guide to Air Sealing a Home

The blower door test will reveal whether these measures were properly taken during the construction of the home.

1. Air barrier and thermal barrier. 

  • A continuous air barrier/pressure boundary must be installed in the building envelope.
  • Exterior thermal envelope contains a continuous air barrier.
  • Breaks or seams/joints in the air barrier must be sealed.
  • Air-permeable insulation (fiberglass batts) should not be used as sealing material.

2. Ceiling/attic

  • The air barrier/pressure boundary in any dropped ceiling/bulkhead/soffit should be aligned
  • with the insulation and any gaps need to be sealed.
  • Access opening, drop down stairs or knee wall doors to unconditioned space should be sealed.

3. Walls

  • Corners and headers should be insulated and the junction of the foundation and sill plate must be sealed.
  • The junction at the top plate and top of exterior walls should be sealed.
  • Wall insulation should be in continuous alignment/contact with the air barrier
  • Kneewalls should be sealed.

4. Windows, skylight and doors

  • The space between window and door jambs and framing as well as skylights and framing should be properly sealed.

5. Rim Joists

  • Rim joists should be air sealed (air barrier) and insulated.
  • Floors (above garage/cantilever)

6. Insulation must be installed and affixed to the underside of the subfloor plywood.

  • The air barrier must be installed at any exposed edge of the insulation.

7. Crawl Space Walls

  • Encapsulation is recommended including installing vapor barrier at the floor, sealing and insulating the walls and disconnecting the space from the outside.

8. Shafts, penetrations

  • Utility penetrations,
  • Shafts for ducts
  • Conduits for wiring
  • Flue chases that open to the outside or unconditioned space should be sealed.

9. Narrow Cavities

  • The proper insulation solution should be used to block and seal any irregular voids.

10. Garage Separation

  • Air sealing should be done between the garage and conditioned spaces.

11. Recessed Lighting

  • Recessed light fixtures installed in the thermal/pressure boundary should be air tight, IC rated and sealed to the drywall.

12. Plumbing and wiring

  • Batt insulation should be cut neatly to conform to any wiring and plumbing located in exterior walls.

13. Shower/tub on exterior wall

  • Outside walls connected to showers and tubs shall be insulated and the air barrier installed separating them from the shower and tub.

14. Electrical/phone box on exterior walls

  • The air barrier must be installed behind electrical and communication panels/boxes or air sealed boxes should be installed.

15. HVAC duct measures

16. Fireplace

  • An air barrier should be installed on fireplace walls and the doors on a fireplace should be gasketed.

Watch the Blower Door Get Set up in 2.5 Minutes



Thursday, December 31 2020
How to Insulate a Cape Cod House: From A to Z


Towson - Maryland

If you have a Cape-Cod style home and you are wondering if you can air seal and insulate effectively - the answer is yes, however not without a good plan.

Houses with Cape-Cod style framing stem from being built in the 1940's and 1950's when the cost of heating was dirt cheap and insulation was an afterthought.

If you live in this style home, chances are very good that it has not been properly addressed due to the complexities of the way it was built. 

Take a look at this recent Cape-Cod insulation project and what steps were taken to seal and insulate.  This one is located in the friendly residential Southland Hills community of about 200 homes in the heart of Towson, Maryland.  The homes in the neighborhood were built in the 1940s.  


The Comprehensive Energy Audit

Having a home energy audit done when you live in a Cape Cod style home might be a good idea if you are looking for guidance on how to properly go about creating better comfort and lower energy bills.

The good thing about working with an energy auitor that has experience is that you can gain insights and avoid pitfalls from a person that has seen these areas before and knows what to expect.

Partnering with a pro can help set you on the right path towards measureable results.

Bonus Room House!

When I pull up to a home as an energy auditor I have my radar on:  What style home is it?  What is the footprint of the home?  What condition is the home in?  Is the heating and cooling gas or electric?  These are some of the take-off points to begin a great home energy audit.

One thing at this house stood out to me when I arrived.  

I window at the top of a wall within the side gable usually means the house has a "bonus room".  Another, more well known way to describe the style of home is Cape-Cod style.

If you have a Cape-Cod style house then you know it really means the bonus room is really just an extra dose of difficulty.

The small attic behind the wall at the bottom of the sloped ceiling is usually hard to reach and a source for discomfort and dust due to old/worn insulation, poorly sealed hatches and general basic neglect (nobody's judging ya!). 

Panel that leads to attic space behind bonus room wall.                     The attic area behind the bonus room wall.

I find these attics in older homes throughout Baltimore County and Maryland for that matter and if you take a drive through this Southland Hills neighborhood, it is easy to see that many of the 200 homes built in the development are all of similar Cape-Cod style.

energy audit maryland

How to Make Insulation Decisions in a Cape-Cod

The complexities that arise when thinking about how to properly insulate a Cape-Cod style home start to go away the more you see this type of construction style.  The problem for most homeowners is that they are not traveling from home to home to manage insualtion jobs, taking the time to figure all of this out.  

Furthermore, if you are not careful, while expending brain power on thinking through how to insulate the roof or walls or floor, other important things can easily get missed.

For example, HVAC ducts are typically living in Cape-Cod style knee wall attic.  It makes perfect sense.  It is an easy conduit to run duct work to the different areas of the home adjacent to the attic as well as below. 

But, this can also bring a whole new set of issues if the ducts are not maintained or if they are old and have been subjected to other changes the house has undergone through the years.

Take a look at this discovery during a Cape-Cod spray foam insualtion project.


Finding a Good Air Sealing & Insulation Treatment Approach

The best approach to take in a house that is a Cape-Cod configuration is to see what the house has to offer as a starting point.  What I mean by that is to figure out what areas of the space can be easily accessed.



Collar Attic Plan

Treatment to the top flat portion of the attic (called the collar attic) should be evaluated for treatment including sealing and adding insulation. If space permits air sealing and insulation should be installed.

Look at these similarly constructed homes with varying amounts of space above the top flat ceiling.  The lines indicate the approximate ceiling location.


Example Home with only 20" of space                                                     Home Where Audit was Conducted has 36" of space to work


In the two different configurations, literally the difference between 16" makes the difference between being able to work in the space or not.

The good news for this home in the Southland Hills neighborhood is that it had sufficient space for a human to work.

Check out some of the details...



The ceiling measures 7' across.                                                 A hatch that was cut for HVAC in the collar attic.

A pop up inside the space reveals not much room to move, but a good opportunity
to make improvements, nonetheless.


At the end of the day a air sealing and adding insulation to the collar attic was feasible and recommended to the homeowner.  Each Cape-Cod collar attic should be independently evaluated for feasibility.


Sloped Attic Approach

Sloped ceiling portions of a Cape-Cod attic should be evaluated both visually and with thermal imaging.  One possible deterrent for homeowners to treat a Cape-Cod attic is that finished sloped ceilings can be costly to re-insulate. 

But don't over-think or try to over-do the job.  With a few subtle installation techniques, the R-value in the sloped cavity can be increased in some cases and treating areas that are more practical to reach will only improve overall leakage of the ceiling bays.

The solution for this home was to seal the cavity bays from below and from above and leave the existing insulation to keep the project within a budget.


Knee Wall Areas

Another challenge to getting measurable results when air sealing a Cape-Cod style home is getting to all of the small spaces between the roof and the knee wall.

In many cases access will need to be made in several locations, so knowing this and prioritizing improvements is critically important.

As an example, don't re-paint the upstairs bonus room if you are considering insulation or if you are finding this article because you are not comfortable in the space and want to find solutions.

Energy auditing, home performance and the BPI guidelines all work towards finding areas around preexisting homes to treat where the return on investment is positive over time. 

In some instances, costs will outweigh value, but when it comes to treating these inaccessible spaces that have older insulation - the gains in energy savings and comfort can really pay off if a little finishing work is required after the project is done adds a little to the overall cost.

Every situation should be evaluated on a case by case basis and a home energy audit is precisely a way to figure all of this out.

Notice how the front dormer windows create multiple areas that need to be treated, making it a bit more difficult.

Check out how we create access to an attic area that is not currently accessible.


Final Plan: Sealing and Insulating in the Best Locations for this House

The stack effect drives the air change conveyor belt inside your home quite a bit in the heating season. This is due to leakage in the basement and in the attic.

During an energy audit I am literally "on the hunt" for places that air can infiltrate (come into your conditioned space) and exfiltrate (your conditioned air goes out).  Sealing up these two places in cost effective ways is the name of the game!

So, after careful review and consultation between myself and the homeowner, we decided on the following work scope:



Foundation -- Air Sealing / Insulation 

Air seal any penetrations at the accessible rim joist in the basement with two-part spray foam (~60 linear ft) which will also insulate the area to R-19.

Attic -- Air Sealing / Insulation

Cut access in three wall locations to gain access to upper floor attic.  Reinstall the drywall with removable panel for future access if needed.

Treat three existing attic access areas by adding insulation to each and weatherstripping.  (2 wall, 1 ceiling)

Add 5-7” of open cell spray foam to the accessible sloped roof surfaces of the kneewall attic areas (~392 sq ft).

Blow 10” of loose fill cellulose to the flat collar attic using the existing ceiling hatch in the closet (~154 sq ft).

Basement Rim & Band Joist - Every Home Should Get this Treatment by the Way

If you are not sure what the rim and band joist are in your basement and if it is accessible for treatment - you are about to find out!

First, put yourself in the unfinished part of your basement.  Usually it is a utility room with HVAC, water heater and maybe washer/dryer.

Identify your foundation wall at the top and you have found your rim and band joist.



Take a look at how the electrical "main" is coming through the rim joist in the basement of this Towson, Maryland home performance home.  This is happening in a lot of homes.



Look at the size of that hole.  And this is the point - it is a hole going directly to the outside which means this:

Summer: humidity infiltration
Winter: cold air infiltration

Just look at those spider webs.  The spiders like to make their traps where air is moving.  It is instinctual.  So if you see a spider web, air is flowing.

Now get your full frame of reference by watching this short video clip that shows where the electrical main and gas line enter into the rim joist from the outside which appears "invisible", but it is not.


Results - A Look at the Final Project and the Test-Out Numbers


Rim and Band Joist Treatment - Closed Cell Spray Foam

Watch the spray foam team treat a portion of the rim and band joist in this up close and personal clip. 


Knee Wall Attic Treatment Before / After


Example of Knee Wall Encapsulation

Blower Door Results

Many factors drive the overall reduction in leakage that each home is schedule to achieve during a home performance project through the BGE program.  I make this very clear to my customers that for every house I am believe we can get 30% reduction and don't there is a home that I am convinced we can only achieve the minimum required to meet the program standards (10%) - only to exceed that by a lot.

As a result of many audits and challenging situations when I was wrong, the partnership I formed with this customer went a long way.  We both agreed that 20% reduction was a good target and that due to other factors that were not reported here, we will do everything we can to nail the work scope and see where it takes us.

Ultimately, this home performance project achieved an 11% reduction in leakage.  




Initial Blower Door Test In CFM: 3775 Cubic Feet Per Minute at Negative Pressure -50 Pascals



Final Test Out Number: 3255 Cubic Feet Per Minute at negative pressure -50 Pascals




Need Advice on How to Do Something Like This?

If you are interested in making your home more comfortable and more efficient, give me a call.  We can discuss your situation and likely getting a BGE or Pepco Energy Audit is the way to go.  

Incentives through the program can be quite advantageous, particularly for those that know that they have to get this problem resolved once and for all. 

Furthermore, an energy audit can uncover other factors that can contribute to your specific issue as each home is different - even the same model across the street.

Give me a call!  I'd love to help you out!

energy audit maryland

Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.

Tuesday, December 22 2020
5 Reasons Your New Windows Are Drafty (#1 Might Hurt)

Energy auditor and window specials

Written by Eric Gans

I have completed over 1000 comprehensive home energy audits. Believe me, you are not the only one trying to figure out why it always feels drafty - even after replacing windows.  You may be surprised by what we usually find with testing and building science principles...

If you spent a good sum of money in the spring to replace old drafty windows and you find yourself this winter season with drafty new windows - you are not the only one!

So don't feel bad or lose hope that you can actually have a cozy home. You just might have to look in a few other places to get to the real problem.

As a former window contractor turned certified home energy auditor I have been on both sides of the coin.  Early on I was convincing people (with the right intentions and wrong information) to replace windows to solve draft issues.

Now, I am on the other side getting called out to do an energy audit to check windows because it is cold and the new windows still seem drafty after installation. 

It took me years to figure it all out, but when you stop and think about it all for a moment - it really makes a lot of sense.  So, with the right fixes and new windows, you can move much closer to complete comfort.  

Here are five reasons why your new window replacement investment might leave you asking: 

Why are my new windows drafty?




1. The Windows Were Not the Draft Source to Begin WithA draft from a window may not be from a window

FACT:  Windows Account for Only 10% of Total Air Leakage in a Typical Home

A misconception for most homeowners is that windows are the only location in your home's "shell" that air can get in and out. 

But, there are many other places around your house that might be much more connected to the outside than windows.

And, a lot of these gateways are hiding in plain sight!

If your home is stubbornly drafty you need to think about your home in three-dimensional ways. 

This does not mean that you wasted money on windows, or that you need special glasses.  It just means that you need to shift your hunt for the drafts by starting to look up and down instead of only through the sides.

FACT:  Most Window Salesman Talk About U-Factor and Solar Heat Gain Coefficient

Guess what...neither measure for air leakage!  Why, you ask?  It is not as important as they lead you to believe.


Read on to learn about the stack effect and how getting the basics from this physics phenomenon can help you begin to think in three dimensional ways about drafts.


2. Understanding Stack Effect & How it Can Solve Your Draft Issue

In the book Rich Dad Poor Dad by Robert T. Kiyosaki, he talks about how as school children we are never really taught the vital lessons of personal finance and how to stay out of debt and save for the future. A drafty window may not the issue due to stack effect

Similarly, I say everyone should learn about the stack effect when ready to purchase a home. 

Understanding how it can play a big part in the drafts that are felt around your home could go a really long way towards better comfort and energy efficiency.

The stack effect can be simply understood by taking one concept we all learn as young children:  Hot Air Rises

Here is the part they don't tell you when it comes to your home.

When the warm air rises in your house it escapes through all of the holes in your ceiling right up into the attic - especially if there is no air-barrier in place or if the air-barrier is mis-aligned. 

Many of the holes where this is happening you cannot see, but they do exist!

This problem causes a conveyor belt in a sense. When the warm air goes out at the top new cold air gets drawn in down low - from the leaky parts of the basement or an open crawl space.

Stack effect is why recessed lights and rim joists should receive way more attention than windows. A slotted recessed light is no match for the warm air pressure and it drags cold air in down low.  As a result - your comfort and money go right into the attic.

drafts from windows may be caused by recessed lights

Slot filled recessed light with light bulb removed.

Leaky recessed lights may be one example of why you feel drafts despite thinking things were sealed up once the windows were installed.

You are not convinced your basement is leaky?          Watch this!



Here are a few other articles that you might find useful if you like this one...
The Real Reasons Your House is Always Cold  |  5 Easy Ways to Seal Up Your Home  
How Much Insulation Does Your Attic Need in 2021?  |  How Much Does Attic Insulation Cost?



3. Fireplace Flue & Recessed Lights - Sealing Up "Gateways" to the Outside

If you just put brand new windows in and you still feel drafts, then look around a bit.  One easy way to find drafts is to look for the "gateways" to the outside. 

For example, one out of every five customers that I do an energy audit for do not have the flue shut on their fireplace chimney which is a huge gateway to the outside.  

Recessed lights are also gateways to the attic (outside) and it is a good practice to check the dampers on any exhaust fans you have venting to the outside. A mis-aligned, damaged or non-existent damper can be a real draft maker.

Solutions include covering and sealing can lights at the attic floor, improving exhaust terminations and using chimney "balloons" to seal faulty flue dampers.

Recessed lights are the source of home drafts

Check out these unsealed recessed lights.
Watch the blower door test reveal air leakage through a recessed light fixture



4. Improperly Treated Crawl Space/ Basementwhy windows are drafty


If the construction style of your home is on a crawl space that is open, then you might experience high drafts. 

An open crawl space will allow unconditioned air into the the crawl space and unless there is a proper pressure boundary separating the foundation area from the room above, then drafts will surely occur through the floor.

If you have a full basement it is very likely that the rim joist in any finished or unfinished area has not been properly air sealed and this will allow air infiltration in the basement area that will cause drafts through walls and floors into the living space above.



How to Seal Up an Unfinished Basement Rim Joist



5. Improperly Installed Windows


Another possibility for drafty new windows, however the least likely, is that the windows were installed improperly or worse yet, not caulked and sealed. 

Even if this is the case, it would still be difficult to make a draft problem worse with new windows even if the windows are incorrectly installed due to pressure dynamics in a house. 

It is important to note however, that basement windows and windows on the second floor could be susceptible to leakage if not properly installed and sealed due to higher pressure.



Watch this typical replacement window installation to get more perspective on your building's shell. 
Only replacing windows is not likely to change whether air is infiltrating into your home.

Watch how a window should be foam sealed once set in the structural framing. 




Drafty Window Solutions: What will actually work?

Get a Comprehensive Home Energy Audit if You Canair leakage testing new windows

A great way to deal with the issue of drafty new windows is to have a comprehensive home energy audit performed. 

An energy audit includes a blower door test.  A blower door test is an air leakage test on your house.  It is a large fan that pulls air out of the house.  When the air leaves at the front door new air replaces it from the holes and cracks around the house due to the negative pressure it creates.  

A great energy auditor will take you around so you can check the windows as well as other common sources of home air leakage so you can judge for yourself which is worse.

If you decide not to have an audit then you can follow additional guidance about how to seal up your home and do some things yourself.

Then, you can target the areas of the home that are leaking the most.  Soon you will be on the path to a more comfortable and less drafty home!

Do It Yourself Tips

It an energy audit is not an option and you are looking for effective ways to reduce drafts, you can try these things:

-Seal can lights (recessed lights) from inside.  Watch how:

-Go to your local hardware store and pick up a can of one-part spray foam and find some of the easy to reach cracks and crevices at the basement rim joist.


I would like to hear your comments about this article.  Feel free to post something below...

Sunday, November 29 2020
Why is My House So Cold?  The Real Reasons


Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.

If your house is cold there are likely several reasons for the problem. 

The reason most think their home is cold: windows, doors and HVAC.

But, if you really want a more comfortable and energy efficient home then the places you really want to look are not where you might think. 

Take it from an energy auditor with over 1000 energy audits and blower door tests completed - these are the things that will actually give you the very best return on investment.

More Focus on HVAC Ducts Rather than Replacement

Every homeoewner should familiarize themselves with their HVAC duct system.  A disconnected duct can not only cause a room to be cold, but it can disrupt temperatures throughout your entire home.

Air Pressure

If you stop and think about it, so many things in our lives are working for us because of air pressure.  For example, tires.  Air pressure inflates the tire so that driving, riding, mowing etc. can happen with good performance and comfort.  No air - no good!

Inside our homes, air pressure is used in a variety of ways.  One example is plumbing.  What happens when too many people try to take a shower at one time?  The air pressure drops with so many open taps so the overall pressure of the water decreases as a result.

Air Pressure and Comfort

Air pressure is also used to heat and cool our homes. If you have air ducts, there is a whole lot happening inside the duct system each and every time the unit is running.

The ducts are the primary mode of transportation for the warm air to flow and service the rooms it was mathematically sized to do.

In an HVAC system that uses air ducts the blower pushes the air through at a specific velocity or flow.  The size of the ducts relies on the force of the blower to get the air to where it needs to go. 

So, similar to a train arriving to an place where the track has been removed and not being able to get any further - if there is a disruption to a portion of the duct system - the air will not get to where it needs to go.

Ducts in Attics and Crawl Spaces

Although it is entirely possible, it is highly unlikely that the rigid ducts that run through your walls and inside the "envelope" of your home are or ever will be disconnected.  As an example, the ducts in the unfinished part of your basement (inside envelope) have likely been there since the beginning and they have not collapsed under their own weight!

The ducts that give the most problems are those that are in the attic or crawl space.  The two main things that I see that contribute to the issue are:

1. The use of flexible ducts that branch off of the main supply plenum are much less forgiving when moved, bumped or subjected to some of the harsh temperatures in an attic.

2. Poor workmanship likely due to the pure simple fact that working in an attic or crawl space is not pleasant and it is human nature to want to get the job done and get the heck out!

Disconnected Ducts or Poorly Sealed Ducts

When you happen to be walking around in a part of your home that has an attic above you - look up.  If you have air vent supply registers in the ceiling then the chances are very high that you have HVAC ducts in an attic space.

The next questions you should be thinking if you do have vents in the ceiling is when is the last time you went to the attic and had the ducts inspected?

This attic inspection during a home energy audit in Maryland demonstrates the importance of having attic and crawl space ducts routinely inspected.

Why Does it Go Unnoticed?

The first idea that comes to most people's minds when a room in the house is not quite as comfortable as other areas or rooms is that the windows are bad.  

In fact, it is not uncommon to do a home energy audit for a mechanical engineer that knows pretty much everything there is to know about an HVAC system, but they did not realize that the duct above their head might be the reason that they are having a comfort issue, rather than need to dense pack insulate a finished southern facing exterior wall.

The Impacts a Loose or Disconnected Duct Can Have

If a duct is disconnected it is not delivering the air to the location that it is supposed to.  Obviously, that particular location suffers.

Due to static pressure, the entire duct system is effected when one duct is disconnected or if all ducts are very loose!  When the pressure inside your duct system is radically changed, with a disconnected duct as one example, it can cause temperature variances in other parts of the house.

What Can You Do?

The best thing to do is take advantage of any home assessment program in your state that includes the technician going into your attic or crawl space as part of the inspection process.

For example, in Maryland a BGE or Pepco customer (power utilities) can get a comprehensive home energy audit for $100 which includes a detailed inspection of the entire thermal envelope of the home.  As part of the energy audit, HVAC ducts are assessed and testing can also be done, if necessary, to determine how leaky the ducts are when the system is running.

If You are Cold Always Think Attic and Basement First

One lesser known place compared to windows and doors to get air leakage sealing done and earn big savings is at the attic floor and in the basement.  Because heat rises and other pressure dynamics inside of your home, most of a the warm air leaves through the ceiling and into the attic (outside).  And, most of the cold air infiltration occurs in the basement or at the foundation level.


Basement Rim Joist Air SealingCold leaky rim joist

Simple sealing and insulation can go a long way in the right places in a basement.  Often times the first instinct is to insulate the walls of the basement.  But, the rim joist is much leakier and will yield much bigger gains when treated - for much less cost.

If you are not familiar with the rim joist in your basement, take a look at the walkthrough video below. 


If you have an unfinished area of your basement look at the top of the foundation wall for the rim joist area.  Here is a tip:  if you see spider webs dangling around then chances are you have air leakage in the general vicinity.

How Does My Basement Leak Cold Air?

A good way to understand why a basement or lower point in a home is more likely to leak cold air is to think about the Empire State Building.  Whether you have been there or not, you might recognize that any larger building has some type of a revolving door at the entrance.  In many cases, buildings have a double door solution where you open a door walk five steps and then open another door.

The reason for these solutions is because of pressure due to the stack effect or chimney effect.  On certain days, the door might not be able to be opened or could blow off due to pressure dynamics inside and outside of the building.

Stack Effect

The stack effect can be simply understood by thinking about a wood burning fireplace.  When the fire is going, the smoke and heat rises up and out at the top.  That is a positive pressure dynamic.  At the base of the fire, the fire is "sucking" up oxygen - the negative pressure.

In a building, the dynamics are similar.  The warm air rises and escapes through cracks and crevices creating a positive pressure dynamic - similar to the stack effect.  Downstairs, in the basement, where there are cracks and crevices, particularly at the rim joist, cold air is drawn or "sucked" in.

For this reason we will recommend to air seal the attic floor and the basement rim joist every day all day over windows and doors.  If you follow the science and try this out in your own house on a clear, dry mid range temperature day.  Open the upstairs windows and watch the curtains get sucked against the screen wanting to flow out and open a first floor or basement window and watch curtains flap towards the inside from the air being drawn in.


If your home is perpetually cold then take note of where your HVAC ducts traverse through your "building's shell" and where perhaps there could be room for issue or improvement.  Delivery of the air is equally important to the creation of the air.  And, everyone must pay close attention to the details of their attic floor.  Creating a continuous air-barrier (not to allow any air to pass through) is critical to a comfortable and energy efficient home.


I would like to hear your comments about this article.  Feel free to post something below...

Thursday, November 19 2020
Crawl Space Encapsulation: The Basics

Let's face the facts about crawl spaces.  They leave a lot to be desired.  

Most crawl spaces are difficult to access in most cases they are stuffy, dusty and full of insects.

To make matters more complicated there are so many questions about how to properly seal and insulate an open crawl space.  For example:

When should crawl space vents be open?
Does an encapsulated crawl space need isulation at the ceiling?
How much does it cost to insulate a crawl space?
What is the best way to encapsulate a crawl space?
Do I need a vapor barrier in my crawl space?
What does it mean to seal a crawl space?

As an energy auditor, certified through the local Maryland utility, it is important to properly examine a crawl space in a number of different scenarios which can be complicated.  My method of simplifying the way I think helps me figure out the right solutions and explain them in easy to understand ways to the the homeowner.  

The information below are common insights required to make an informed decision about how to properly treat your crawl space.


Old School Thinking:  I See Insulation Everything is Fine

If you live in a home on a crawl space there is a very good chance that you think that this just is the way it is and there is not much you can do.

When you first moved in you ambitiously went into the crawl and you saw insulation below the floor.  Everything seemed fine.    

Maybe you have never looked in the direction of your crawl space, or any crawl space for that matter, and have no ideas on what one may look like.

If that is the case, have a look at this video taken during a BGE energy audit of a typical open crawl space.


When Should Crawl Space Vents be Open?

Open Crawl Space Vent Example

If possible, crawl space vents should always be blocked and sealed.  Crawl space vents provide virtually no benefit by being open.

Creating vent openings in the foundation wall were designed to allow "fresh" air into the crawl space for ventilation.  Millions of homes have been built using this method.

The problem is that you can't control what air moves into the crawl space and when it turns hot and humid or cold and dry, the open vent solution is not the best for climates that have seasonal changes like Maryland.

You cannot count on enough dry, average temperature days in a row to sufficiently dry out the crawl space.  Additionally, considering the vents are typically not nearly large enough or often times obstructed, your crawl space does not stand much of a chance for success and as a result, your indoor comfort and air quality suffer and your energy bills are high.

Check out one common issue due to open crawl space vents.

Open Crawl Spaces: Two Seasonal Problems

Summer Humidity

Inside look at a crawl space vent.Open vents allow humid air into the space, or worse streaming water, which tends to get trapped and migrate to unwanted places. 

So many of us plug up our dehumidifier in the summer to keep the basement dry. 

Those with open crawl spaces likely have two machines working and they may not be able to keep up with the high humidity. 

Open vents in a crawl space can have a significant impact on indoor air quality and are main factors in high indoor humidity levels.

Eighty percent of crawl spaces in humid climates have insulation that has fallen. Wood structural flooring components should not be subjected to moist, humid conditions for long periods of time.

energy audit maryland

Winter Issues and How Physics Plays a Role

During winter months, cold winter air is actually pulled into the vents due to physical dynamics that are at play - known as the stack effect, or chimney effect.  Insulation is unable to prevent infiltration through the floor.

Negative pressure is created in a crawl space when it is connected to the living space above.  As warm air rises and finds places to escape, it tugs the cold air from below right on in as seen in the diagram to the right.

Unconditioned cold air that migrates into the crawl space through the vents is then conveyed up through the floor and walls and into your living space.  

Therefore, as a result of this physical characteristic of most buildings, having an open crawl space is not a good solution if you live in a location with a cold season.



If You Have a Crawl Space – You Have an Energy Efficiency "Point of Weakness"

Big problems with comfort and high energy bills stem from irregularities in the building shell.  Twists and turns in a home’s design create more complex treatment solutions in locations such as:

  • Porches
  • Roof Overhangs
  • Shafts for Chimneys & Pipes
  • Protruding Windows & Doors
  • Indented Windows & Doors
  • Cantilevers
  • Garages
  • Knee Walls
  • Open Basements
  • Open Crawl Spaces

Most of the largest leaks in homes occur where framing (such as floor joists or wall studs) span from an area inside conditioned space to an unconditioned or vented space, such as the attic,crawlspace, garage, or roof. Appropriate blocking is needed in these instances and it requires a team that knows home performance techniques and solutions to do it right.

Does A Crawl Space Need a Vapor Barrier?


Your crawl space needs a properly sealed vapor barrier.  Ground moisture will wreak havoc on your wood flooring, joists and indoor air quality if left un-checked.  A fully encapsulated crawl space will always include a sealed vapor barrier.

Watch: Properly Installed Crawl Space Vapor Barrier


What to Look for In Order to Prescribe the Proper Treatment for an Open Crawl Space

No general rule should be applied to how to treat a crawl space. 

These three factors should be considered first:

1. Climate
2. Ground Dampness
3. Presence of Ducts in the Space

In Maryland we tend to have hot, humid summers and sometimes it can be damp well into the fall.  The winters bring cold snaps, some longer than others, that can put a significant load on any HVAC system. 

Seasonal changes make sealing crawl spaces in our region a good option.  Typically, ducts are in crawl spaces in homes where this foundation type exists.

Crawl space inspections will require defining the best place to establish or re-establish the thermal boundary.

The thermal boundary can be described as the location that divides the inside living space from the outside, unconditioned space of your home.

Most crawl spaces are outfitted with insulation at the ceiling.  And, most crawl spaces are sources of energy loss and comfort problems.


If I Have Insulation in My Crawl Space Ceiling, Why is it Such a Problem?

In order to understand any high-performance crawl space insulation retrofit, you must first understand the three key things that getting results are dependent upon:

  1. Proper Installation of an Air Barrier
  2. Proper Installation of a Sturdy Vapor Barrier
  3. Proper Installation of Insulation

Typically, all three key factors are missing in a crawl space.

If not properly sealed, penetrations at the crawl space ceiling (floor inside) will lead to communication of air between the two areas.

A vapor barrier is only good if it is 100% sealed, otherwise moisture will still migrate up and into your living space.

Fiberglass batting insulation is difficult to install in almost all applications.  The thermal performance of batt insulation is heavily dependent on proper installation.  To attain maximum R-value, the batt insulation should be in continuous contact with all the surround cavity surfaces where they are installed.  They need to be cut exactly to length because if they are too long they bunch up leaving the area to be insulated exposed and if too short, spaces are created that promote convection.


Open Crawl Space vs. Encapsulated Crawl Space

Past research has shown that a conventionally vented crawl space that has been converted into an non-vented and conditioned space tends to operate similarly to houses with basements, with several benefits for the homeowner: 

• Energy savings
• Comfort
• Moisture control
• Long-term durability
• Healthier air quality

Open crawl space with insulation at the ceiling and an improperly installed vapor barrier.


Watch: Take a Look at a Completed Crawl Space Project Including Blocked and Sealed Vents

Reasons Maryland Homeowners with Crawl Spaces Might Not Choose to Encapsulate

  • Significant efforts can be made with ease to seal and insulate ducts, air handlers, water heaters, pipes etc.
  • Lacking any paid heat source, the crawl space is consistently between ground temp and outdoor temp which is typically above 32 degrees
  • The floor has had significant air sealing and insulation work performed already; some investment has taken place
  • The cost to seal and insulate the floor is considerably less then encapsulation for some reason

A Big Opportunity That Often Gets Overlooked

Too often the ducts that are running through crawl spaces are asked to do way too much. 

Not only do they need to carry conditioned air to the furthest reaches of your home, but in some cases they are expected to transport 90 degree air through a duct that is super cooled to 25 degrees on the coldest of days.

Sealing a crawl space from the outside can drastically improve the performance of your HVAC system and will contain duct leakage because the immediate barrier outside of the ducts also plays into the amount they leak.

For example, ducts that run through an open crawl space will leak much more due to the pressure dynamics compared to an encapsulated crawl space.

How to Properly Encapsulate a Crawl Space

It is important to not begin a foundation insulation retrofit project until it is well drained and dry.  Drainage should be the priority if the crawl space recurring takes on water.

Next, the crawl space should be free of debris and items that might impede the ability to install a vapor barrier.  A thick plastic vapor barrier should always be installed in crawl spaces with dirt floors.

The vapor barrier should be sealed to the walls, piers and any other penetration from the ground.

Crawl space walls should be air sealed and insulated (typically by using a rigid foam board with high R-value) all the way up to the rim joist.  The rim and band joist should be air sealed and insulated.


Do you live in Maryland and need advice on how to treat your crawl space?

If you are interested in making your home more comfortable and more efficient, give me a call.  We can discuss your situation and likely getting a BGE or Pepco Energy Audit is the way to go.  

Incentives through the program can be quite advantageous, particularly for those that know that they have to get this problem resolved once and for all. 

Furthermore, an energy audit can uncover other factors that can contribute to your specific issue as each home is different - even the same model across the street.

Give me a call!  I'd love to help you out!

energy audit maryland

Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.

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