The Home Envelope Theory

The Home Envelope Theory

The core concept for understanding, creating, and maintaining a comfortable home environment. The home envelope is what allows homeowners to live comfortably. 

What Is The Building Envelope?

The building envelope is what separates the indoors from the outdoors.

All the elements of a building that comprise that separation work together to create a comprehensive barrier between the two environments.

Every home envelope is different, but there are similarities across structure types. These differences appear most prominently across different climates, regions, and biomes.

Find out more about the building envelope below.

What Does The Building Envelope Do?

A home’s “building envelope” is a key part of its defense against the weather, harsh conditions, and an uncomfortable living environment. It is an abstract term which defines the most practical and minute components that, together, create a livable and durable enclosure.

In a broad sense, think of the home’s envelope as the “outline” or silhouette of a house. It is comprised of the connecting exterior layers that separate the indoors from the outdoors. The graphic to the right shows an outline of a home, as well as its many fenestrations.

Roofs, walls, windows, and doors are the primary components of a building envelope. However, the term applies to any additional openings or barriers (air conditioners, chimneys, doggy doors, etc.) that bridge the gap between the natural outdoors and the constructed indoors.

Every aspect of a building envelope has a role to play in keeping a home secure, comfortable, and controllable.

Complex Roofing, Wall Systems

Within each component of the building envelope lies a deeper system of construction. The building envelope is not merely the home’s outer shell; it is the combined efforts of each ingredient in the property’s recipe.

From the insulation in the roof through the joists in the floor, all of the minutiae
involved in building a functioning home are considered part of the building envelope.

Poor insulation in roofing and walls are some of the most common reasons for a home’s reduction in energy efficiency. On top of that, it’s one of the last places homeowners think to look.


Fenestrations are the industry term for intentional opening areas in the building envelope where the indoors and outdoors can meet. These are primarily doors and windows, but also includes of skylights, chimneys, etc.

As the primary opening of choice in the building envelope, fenestrations are extremely common locations for improper air sealing. Loose door hinges, leaky windows, and poorly installed additions can allow energy to seep out from the home, which is a detriment to utility costs and energy efficiency.