What is Building Envelope?
Building envelope is common terminology used in home improvement or insulation projects. Despite its ubiquity, not a lot of people understand what a building envelope is.
In this article, we’ll be exploring the definition of building envelope as well as other frequently asked questions regarding the subject.
Building Envelope Definition
A simple definition of building envelope is the separation of the interior and exterior of a building.
The envelope serves to protect the interior while facilitating climate control. Building envelope encompasses the entire exterior building system of your home. This includes your windows, doors, roof, floor, foundations, and insulation.
When people talk about energy efficiency solutions like LED bulbs or low-flow faucets, none of that will be of much use if your building envelope isn’t up to snuff. Let’s look at what function a building envelope serves in a home.
What is the Function of a Building Envelope?
As you might expect, building envelopes serve a variety of functions.
One such purpose is support. Building envelopes ensure strength and rigidity. Structural support is a key component of a good building envelope, as it determines how your home can handle external loads and forces.
Another function is control. This is where building envelopes enter into conversations about energy efficiency and climate control. A good building envelope ensures better control over your home insulation or the ability to keep warm or cold air indoors. Facilitating the passage of water, heat, and condensation between the interior and exterior of the building is a crucial function of building envelopes.
Aesthetics and looks are also important considerations for building envelopes. Proper envelopes help your building look more attractive, though it’s relatively secondary to its control and support functions.
Why is Building Envelope Important?
Building envelope plays an important role in protecting the occupants of a building from the elements and helping to regulate the indoor temperature.
In addition, the envelope plays a critical role in energy efficiency. By keeping heat inside during winter and outside during summer, the envelope helps to minimize the need for heating and cooling.
As a result, buildings with well-insulated envelopes can save a significant amount of energy. In today’s world, where sustainability is becoming increasingly important, the building envelope is more important than ever.
What are Building Envelope Solutions?
Before we discuss building envelope solutions, we first need to look at common issues. Identifying common problems with building envelopes will allow you to diagnose different solutions better.
Interior building envelope issues include:
- Staining of interior walls and ceilings
- Water-damaged insulation
- Water-damaged soffits and sills
- Peeling of wallpaper
- Stains and dirt along window tracks
- Stains alongside AC units
Exterior building envelope issues include:
- Rust marks
- Spalling brick
- Cracks that go through the masonry and mortar
- Discolored stone or masonry
- Signs of condensation on grass
- Roof seam splits
Many of these building envelope issues are signs of wear and tear or leak in your systems. Contacting your local contractors for an accurate quote on these symptoms will set you on the right track toward viable solutions.
These solutions might include replacing insulation, re-applying wallpaper, reconstructing walls and masonry, or replacing steel joints that’s beginning to rust.
How Can I Make a Building Envelope Better?
If you want to improve your building envelope, there are plenty of ways to go about it.
Which improvements you make depend on the issues your home might be having or your ultimate energy-efficiency goals. Here are a few ways you can improve your building envelope.
Building envelopes can be drastically improved if you apply proper insulation. Because insulation gives you much more control over your home temperatures, it’s the go-to move for achieving greater energy efficiency.
Many older buildings either need more insulation as requirements have changed or older materials have deteriorated. Get a professional contractor to check out your current insulation and determine whether or not you need to add more.
Another spot in the home that routinely leaks air are doors. Whether it’s on the front porch or doors connecting your rooms, doors are prime areas for cold or warm air to escape.
Luckily, many modern doors are designed to keep warm or cold air inside and accommodate instances where people are going in and out of a building. They’re also less leaky, providing better home insulation and building envelope.
Likewise, modern energy-efficient windows help keep cold air from escaping in the summer while keeping similarly frigid air out of your home in the winter.
If you don’t have the money to invest in energy-efficient windows, window film might be your next best bet. Window film on your windows can block UV rays from entering your home by reflecting them to the sun. These films help retain warmth in your home while keeping heat out during the summer.
In any case, your windows can often be improved to boost your building envelope.
Your roof is a crucial part of keeping your home cool in the summer, but constant exposure to the sun can deteriorate it over time. This leads to more leaks and poorer climate control, decreasing your building envelope.
Roof coatings can help prevent that by reflecting solar radiation. This keeps your attic and the rest of your house much cooler in the summer. It elongates your roof’s life span and keeps your building envelope high even during the hottest months.
What is a Building Envelope Specialist?
A building envelope inspection is a survey conducted by a building envelope consultant or expert to look at different aspects of your building envelope to determine its integrity.
The main focus is ensuring all the components – the roof, windows, doors, walls, etc. – can keep exterior elements outside of the house. For example, a building envelope inspector might try to find vulnerabilities in your home if your interior is experiencing water leaks.
Specific tests and procedures standard in a building envelope inspection include:
- Moisture and water analysis
- Building forensics
- Temperature testing
Overall, building envelope inspections illuminate specific building-related issues, which is crucial for improving their overall envelope and making home improvements.
What is another term used today for building envelope?
One term sometimes used today as a synonym for “building envelope” is “building enclosure.”
Both terms refer to the physical barrier that separates the interior of a building from the outdoor environment and includes the walls, roof, windows, doors, and foundation.
The building envelope or building enclosure plays an essential role in protecting the interior of a building from external elements such as weather, moisture, and pests and in maintaining comfortable indoor temperatures and air quality.
Other related terms include “thermal envelope” and “weather-resistant barrier.”
What does a building envelope consist of?
A building envelope, also known as a building enclosure, typically consists of the following components:
- Roof: The roof is the uppermost part of the building and provides protection against rain, snow, and other weather elements.
- Walls: The vertical surfaces surround the building and provide structural support and insulation.
- Windows and doors: These components provide access to the building and allow natural light to enter. They also play a critical role in regulating air flow in and out of the building.
- Foundation: The foundation supports the weight of the building and provides a stable base. It is typically made of concrete or masonry.
- Insulation: Insulation is installed within the walls, roof, and floors to reduce heat transfer and improve energy efficiency.
- Vapor barrier: A vapor barrier is a material layer that helps prevent moisture from entering the building.
- Air barrier: An air barrier is a material layer that helps prevent air leakage in and out of the building.
- Cladding: Cladding refers to the exterior finish material that is installed over the walls and roof of the building. It protects against weather elements and also contributes to the aesthetic appearance of the building.
These components work together to create a continuous barrier that separates the interior of the building from the outdoor environment and helps to maintain a comfortable and healthy indoor environment.
What typically contributes to building envelope failure?
Building envelope failure can occur due to a variety of factors, including:
- Poor design: Building envelope failure can occur if the envelope design needs to be more appropriate for the climate and weather conditions in which the building is located. For example, it may fail if the envelope is not designed to withstand high winds or heavy rain.
- Poor installation: The quality of installation is critical to the performance of the building envelope. If the envelope is not installed correctly, it may have gaps, leaks, or other defects that can compromise its ability to protect the building.
- Material deterioration: Over time, the materials that make up the building envelope can deteriorate due to exposure to the elements, such as sunlight, moisture, and temperature fluctuations. This can lead to cracks, gaps, and other defects allowing water, air, and pests to enter the building.
- Lack of maintenance: Regular maintenance is essential to ensuring the long-term performance of the building envelope. Failure to maintain the envelope, such as not repairing leaks or replacing damaged components, can result in the deterioration of the envelope and, ultimately, its failure.
- Physical damage: Building envelope failure can also occur due to physical damage, such as extreme weather events or accidents.
Building envelope failure can lead to various problems, including water damage, mold growth, reduced energy efficiency, and compromised indoor air quality. Regular inspection and maintenance of the building envelope can help to prevent failure and ensure the long-term performance of the building.
What are building envelope requirements?
Building envelope requirements can vary depending on the location of the building and the specific building code or applicable regulations. However, in general, building envelope requirements are designed to ensure that the building envelope provides adequate protection against weather elements and is energy-efficient.
Some standard building envelope requirements include:
- Thermal insulation: Building codes typically require a minimum level of thermal insulation to be installed in the building envelope’s walls, roof, and floors to reduce heat transfer and improve energy efficiency.
- Air leakage control: Building codes also typically require measures to be taken to control air leakage through the building envelope, such as installing air barriers and sealing gaps and cracks.
- Water management: Building codes require the building envelope to be designed and constructed to manage water infiltration, including installing a water-resistive barrier, proper flashing, and adequate drainage.
- Structural integrity: The building envelope must be designed and constructed to provide adequate structural integrity to support the loads placed on it, including wind, snow, and seismic loads.
- Fire resistance: Building codes may also require the building envelope to meet specific fire resistance standards to limit the spread of fire and smoke.
Many resources are available to help understand building envelope requirements, including building codes, regulations, and standards. Some helpful references include:
- International Building Code (IBC)
- ASHRAE Standard 90.1 – Energy Standard for Buildings Except for Low-Rise Residential Buildings
- National Institute of Building Sciences (NIBS) Whole Building Design Guide – Building Envelope Design Guide
- American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Handbook – Fundamentals