What is a Building Envelope?

When talking about the construction of a home, and especially when it comes to insulation, the term building envelope is thrown around a lot. But what exactly is a building envelope? Despite the importance of this feature, many people don’t quite understand what it is.

What is the Building Envelope?

Simply put, the building envelope is what separates the interior of your home from the outside elements. The envelope of your building plays an important role in protecting what’s inside while helping to control the indoor environment. 

The building envelope can be thought of as everything that touches the outside, including everything from the attic, down to the doors and windows, all the way down to the basement or crawl space. The most important factors that contribute to a good building envelope include the seals around windows and doors and the insulation.

These days people are constantly thinking about ways to make their home more energy-efficient, such as through the use of low-energy light bulbs, as well as water-conserving faucets and toilets. However, most homeowners are unaware that all of these fancy upgrades will have little impact without a solid building envelope.

No amount of high-tech energy-conserving light bulbs will be able to overcome the energy that could be wasted by an envelope that isn’t sealed properly.

What Does it Do?

Climate Control

The most important function of a building envelope it’s to increase the ease at which you can control the climate within your home. The building envelope is critical to controlling the passage of water, air, and heat between the inside and outside of your home. Maintaining the flow of all of these elements is critical not only in order to increase the energy efficiency of your home, but also to protect against other issues caused by the elements, such as mold.


Another important function of the building envelope is to lend additional strength and support to your structure. Having a rock-solid building envelope can lend additional structural Integrity to your home.


Although probably the least important function of a building envelope, having one can also increase the general attractiveness of your home. Having a good unified building envelope can make your home more aesthetically pleasing, and therefore increase its overall value.

How to Achieve a Good Building Envelope

There are many different ways to ensure your home has a good building envelope. Each situation is unique, but in most cases creating a good seal around your home may require a variety of different approaches.


The effectiveness of your building envelope can be improved dramatically through the use of insulation. Adding extra insulation is an easy way to achieve higher levels of energy efficiency in the home, by giving you more control over your indoor temperature.

While there are many different types of insulation available, spray foam is the best choice when it comes to upgrading your building envelope as it can achieve a completely airtight seal, as well as offer a host of other benefits.

Many older homes are either completely lacking in insulation or desperately need to have their insulation updated.  We recommend hiring a professional installation contractor to evaluate whatever insulation you might currently have in your home, and help you to determine if you could benefit from a new or updated installation.


Doors can be a common source of air leaks that are routinely overlooked. Any place a door is leading to the outside is a prime spot for conditioned air to escape.  Thankfully, most modern doors are cleverly designed to be energy-efficient, tending to leak less air, and accommodate high traffic.


Having modern windows installed in your home can make a big difference towards keeping your home energy efficient. While installing newer high-tech double or triple pane windows can be highly effective in updating your building envelope, it can be expensive.

If the cost of energy-efficient windows is prohibitory, you may consider using a window film. Just this thin layer of plastic on your window can dramatically increase how much warmth your home is able to retain during the winter while keeping the heat out during the summer.

If you are interested in upgrading your building envelope consider hiring an inspector to come to survey the different aspects of your home to determine its effectiveness. A good inspector will be sure to survey all different elements of the home including the roof, doors and windows, and insulation to ensure they are all working together to maintain an airtight seal.

An inspection of your building will include an assessment of any issues in your building, and suggestions as to what should be addressed if you desire to improve the overall envelope of your structure.