What Is A Building Envelope And Why Is It So Important?


Whether you’re building a new property or renovating an existing one, you might have heard the term building envelope used when talking about the structure.

This is an important part of any property and is something that needs to be carefully considered for any building project.

But what exactly is a building envelope, and why do you need to know about it?

What is a building envelope?

In a nutshell, a building envelope (sometimes referred to as an architectural envelope) is the barrier that protects the inside of your property from the outside elements. Think of it literally like the shell or structure that envelopes the building.

It is designed for climate control, protection and structure, amongst other reasons, but we’ll look at these in more detail later.

What makes up a building envelope?

A building envelope is not just one thing. In fact, it is made up of all the structural elements that separate the inside from the outside of a property.

Essentially, it is the umbrella term for the external parts of a structure. So a building envelope is made up of aspects like:

  • Roofs
  • Walls
  • Windows
  • Cladding
  • Doors

Each of these aspects must be perfect, and they must work together to create the most energy efficient and strong structure possible.

The different types of envelope

There are two main types of building envelope; they are either defined as either tight or loose.


A tight building envelope, as the name suggests, is designed to create a tight seal around the property. This is done using insulation, sealant and more energy-efficient glazing.

The reason for creating such a tight seal on a property is for internal climate control. If the building is sealed effectively, the warm or cold air inside cannot leak out, giving the inhabitants more control over the indoor temperature.


On the other hand, loose building envelopes are designed to allow for more natural ventilation. This means the air can flow more freely throughout the structure, reducing the need for mechanical means like air conditioning units.

This can be beneficial for a number of reasons, but this style of envelope is also more prone to unwanted moisture. As such, it has to be very carefully designed and constructed for the best results.

Functions of a building envelope

We’ve briefly begun to touch on this, but now we’re going to look in more detail at the three key functions of a building envelope.

As we’ve said, it is crucial for internal climate control and making the building as energy efficient as possible.

The second function is structure. Since the envelope includes everything from walls to windows, these need to offer structural support and protect the inhabitants of the building from the outside elements.

What’s more, the foundation support must always meet the local regulations and building codes.

Finally, a building envelope will impact the style and finish of the building. For example, you might want to incorporate lots of glazed elements for a sleek glass finish. Alternatively, you might use wooden or colourful cladding for a unique exterior.

So it’s not always just practical; it’s also about creating something that is aesthetically pleasing too.

However, it’s not just important to understand the functions of a building envelope but also the other ways in which this can impact a property. Some of the other important reasons you need to get your envelope right include the following:

  • Movement – As the temperature changes or volatile weather sets in, your envelope must allow for movement without weakening the structure
  • Acoustics – Your envelope needs to protect inhabitants from external sounds, as well as keep sound contained from within
  • Cutting costs – Energy efficiency is vital for saving money on heating and cooling the property throughout the year

Why do you need to know about this?

The simple answer is you need to know about building envelopes to ensure that you choose the best architectural envelope solution for your property. This will help to ensure you choose the right materials for the job and that the work is completed to the highest possible standard, whether this is done by you or by a professional contractor.

Plus, as you can see, it serves some pretty important functions in protecting your property and making it comfortable and inhabitable, so it pays to understand this in more detail.

Therefore, when completing any building project, you must make sure you’re clued up on the architectural envelope and whether a tight or loose option is best. This will ensure that you create a structure that is strong, durable and energy efficient.