Skip to main content
Questions? Call!

Building Science 101

Specialized Maryland Contractor

Using Building Science Principles


Hometrust takes a whole-house approach to home remodeling and improvements.  Our visit to your home includes several steps of investigation and testing to properly diagnose and uncover potential issues in order to recommend energy efficient improvements that will work. 

One of the most important building science principles that should guide home improvement decisions is the stack effect

As seen in this figure, warm air rises in a home.  This concept is not new.  What is important to know is that the warm air that rises, if left unchecked, leaves the house through the gaps in the ceiling.  What gaps you ask?  That is what home performance is all about!  Uncontrolled air leakage occurs when air moves through gaps or openings in walls, floors, ceilings, duct work, doors or windows and is often a major source of energy loss in homes.

As the warm air leaves the building, outside air is pulled in to replace the air that escapes.  This is a physics phenomenon.  The term stack effect comes from this dynamic that happens in the residential building, much like the characteristics of a  chimney that while in use billows smoke at the top while the fire pulls oxygen in down at the base.  

This pressure dynamic is what wreaks winter time havoc on energy bills and comfort and it also hampers summer indoor conditions as well.

The typical leakage points in a ceiling are fans, vents, light fixtures, plumbing holes, floors, walls, ceiling & the foundation.  These are all things that are hiding in plain sight!

Stack Effect - Full View

The stack effect in Maryland

The stack effect conveys your conditioned air out of the house when left to its own devices.  Exfiltration points, as seen to the right, are opportunities to stop the conveyor belt and improve comfort and overall energy efficiency.

Attic Exfiltration Points

Maryland air sealing contractor

1. Plumbing vent bypass
2. Chimney bypass
3. Attic access hatch
4. Interior wall top plate
5. Electrical box bypass
6. Panned return duct
7. Exterior wall top plate

Building Performance Institute Certified
Building Performance Institute
Building Analysts
Envelope Professionals
BGE Approved Energy Contractor
Pepco Approved Energy Contractor

Helping You!

*Improve home comfort
Educate you about your home
*Find air leakage in your home
*Improve energy efficiency
*Use science for solutions
*Assess your building's shell
*Help prioritize improvements
*Find the root causes
*Assess insulation levels
*Measure indoor air quality
*Evaluate windows & doors
*Evaluate attic ventilation

    Specialized Maryland Contractor
    • MHIC Licensed
    • Building Analyst Certified
    • Envelope Professional Certification
    • EPA Lead Renovator Certified


    Hometrust Remodeling's mission is to help Maryland homeowners create a more comfortable home and save energy by using building science principles and modern air sealing and insulation techniques.


    Google Reviews

    Services & Service Areas

    Calvert County, Carroll County, Anne Arundel County, Baltimore County, Howard County, Montgomery County, Prince George's County

    Contact Us
    our facebook page youtube

    MHIC License # 114593
    Approved BGE Energy Contractor
    Approved Pepco Energy Contractor


    Hometrust Remodeling
    North Laurel, MD 20723
    Hometrust Remodeling

    Trust us to put all the pieces together right! 
    ©2021 Hometrust Remodeling | All Rights Reserved

    An Energy Auditor's Purpose 
    "Energy auditors visit residential buildings and talk to owners and residents.  They inspect, test, and measure to decide what energy-efficient retrofits are practical and cost effective." Residential Energy