What is a Home Envelope?
Updated: May 9, 2022
Your home’s envelope is essentially the way your home is designed and structured to be most appropriate for your climate. The building envelope for your home includes the roof, sub floor, exterior doors and windows, and exterior walls.
Essential parts of any building envelope are:
The physical structure - for example, any earthquake proofing along with internal and external supports.
Climate - both internal and external. One must consider the external climate as well as the elements that will go into heating and cooling the internal climate to ensure the ultimate comfort of all residents.
Visual appeal - in the end the structure needs to look nice and have a pleasant finish. In the case of a roof or exterior walls, the “finish” can actually contribute to the envelope’s efficiency in the form of a cool roof or a COOLWALL®.
Every element of your building envelope contributes to your comfort, along with the energy efficiency of your HVAC, air quality, and more.
Loose or Tight Building Envelope
A building envelope can be “loose” or “tight.” This doesn’t refer to whether you live in a tent or a wooden structure, but instead to how leak-proof your home really is.
Traditionally, homes were not built for air conditioning and extensive HVAC systems. They depended upon the overall climate and the structure of the home itself to keep you cool and comfortable in warmer climates - and snug and warm in cold climates.
This tradition has changed as our homes become more dependent upon HVAC to regulate internal temperatures. However, if you have an older home, your envelope may still be environmentally dependent and may not be ideal for the HVAC system you’d like to use. A drafty home in a warmer climate is great if you don’t plan to install an air conditioning system - but not very workable if you want an efficient ac unit.
Dos and Don’ts of Tightening Your Home Envelope
Many Californian homes need to a tighter building envelope to work with the modern conveniences of full HVAC units with heating, air, and filtered ventilation. Here are a few dos and don’ts when it comes to tightening your building envelope:
DO use double paned windows and doors to create a tighter, comfortable, and moisture-safe seal between your indoor temperatures and the outdoors.
DON’T caulk over damp or moldy window sills in order to get a tighter seal. You are just sealing in moisture and mold, which can cause problems down the road.
DO strategically install insulation to block outdoor temperatures from affecting your internal temperatures.
DON’T remove insulation in order to cool your home down in the summer.
DO get a professional evaluation to discover where your home is losing energy.
DON’T blow air through vents on your own. A professional may use special blowers to discover where air is leaching out, but just forcing air through your vents may cause dust and debris to flood into your home.
DO get your HVAC system cleaned and maintained regularly, even if you aren’t sure what else to do to tighten your envelope.
DON’T install an entirely new system without knowing how tight the envelope is.
Are you ready to increase your HVAC efficiency? Contact SF Green Construction to find out how we can improve your home energy function.