What is an Energy-Efficiency Retrofit?

An energy-efficiency retrofit is any improvement made to an existing structure which provides an increase in the overall energy-efficiency or performance of the building.  The following are typical energy-efficiency retrofits which we prescribe, and contract.

  • targeted air-sealing of the building envelope
  • densepack, cavity-fill cellulose insulation for walls, above-grade floors and sloped/vaulted ceilings
  • loosefill cellulose insulation for attics
  • foundation/sill wall insulation
  • basement/crawlspace vapor barrier and sump-pump installation
  • roof gutter installation
  • bathroom/kitchen exhaust fan installation
  • whole-house ventilation
  • replacement heating systems
  • renewable energy installations
  • door and window replacement

What is air-sealing, and why is it important?
Air-sealing is sealing holes, cracks, and gaps in the building envelope where air passes into or out of your home. Over the year, you pay for heating and/or air-conditioning to maintain a comfortable temperature in your home–a house that leaks air costs more to heat or cool.  These same leaks may also create uncomfortable spaces. Sealing air leaks will help maintain year-round comfort in your home, and likely lower energy bills.  Every 1 square inch of air-sealing can save 1 gallon of heating oil annually.

The Stack Effect:  The manner in which air enters, travels through, and exits most homes.  Like a chimney, cold air enters from lower building levels pushing warm air up and out the top of the structure. Locating and sealing those entry and exit points will increase comfort and reduce energy costs.


Thermal Boundary: The thermal boundary of a home is the insulated envelope which is intended to reduce the flow of heat in or out of the building depending upon the season.  Effective insulation depends on a properly aligned and sealed air-barrier to complete the thermal boundary.



Air Sealing Your Home’s Hidden By-Passes:  Airflow within the building envelope also leads to discomfort and high fuel costs.  With my diagnostic equipment I can not only find your home’s significant air leaks, but can put together an airflow dynamic for the whole house.


Insulation:  A combination of air sealing, and properly applied insulation will save you money year after year.  Many contractors and insulation installers do not conduct proper air-sealing, and will often use improperly installed, inferior insulation products.  Avoid the blow-over!!!

The biggest holes are most often found in the attic and basement. These air leaks communicate with other parts of the building assembly in hidden and sometimes unexpected ways. Spray foam, foamboard, dense-packed cellulose, caulking, and weather-stripping are commonly used for air-sealing.

Most homes are not well air-sealed, even new ones. At Sustainable Structures, I use state-of-the-art diagnostic equipment, building science training, and building expertise to both find the problem areas in your home, and contract the fixes.  Following project completion, I conduct a “test-out” procedure (similar to the initial evaluation process) to verify the success of the energy-efficient retrofit.

Leave a Reply