The building envelope is the physical barrier between the exterior and interior environments enclosing a structure.[1] To protect the interior space from environmental factors like precipitation, wind, temperature, humidity, and ultraviolet radiation, the building envelope is typically made up of a number of parts and systems (see figure 1). The inhabitants, furniture, building components, lighting, machinery, equipment, and the HVAC (heating, ventilation, and air conditioning) system make up the internal environment.
One of the best ways to increase energy efficiency is to improve the building envelope of homes.
Table of Contents
A Building Envelope Is What?
“Building envelope” is one phrase that is frequently used when constructing a home. The idea of a building envelope has to do with how the exterior of the home is built and designed. Using exterior wall components and designs that are climatically appropriate, structurally sound, and aesthetically pleasing is essential for a good building envelope. The main components in creating your building envelope are these three components. The roof, subfloor, exterior doors, windows, and of course the exterior walls make up a house’s building envelope.
Tight And Loose Building Envelopes
It is common to use the terms “tight” or “loose” to describe a building envelope. A building’s airflow can move more freely through a loose envelope as opposed to a tight one, which restricts airflow or modifies how it is admitted. In general, a tight envelope is the better option due to Australia’s climate, which is quite variable. The ability to take advantage of the environment and control the indoor climate using the outside of the house is growing thanks to innovations in the design and materials of exterior walls.
Building Support
The building envelope’s structural soundness comes first and foremost. The weight of their own structure, as well as that of the roof and any upper floors, is primarily supported by the external walls. Specially constructed walls known as load bearing walls take on this weight and then transmit it to the foundations. Walls must be strengthened to withstand lateral pressure in regions that are vulnerable to powerful winds and earthquakes. To learn more about any unique structural requirements your home might need to meet, consult your local building codes.
Climate Control
When designing a building envelope, several environmental factors need to be taken into account. A home should have adequate fresh air ventilation for comfort, but it should also be shielded from gusty winds and draughts. Mold and mildew can grow more easily in homes exposed to damp air in cold or humid climates, which is unhealthy and must be avoided. You might choose walls that will trap and release heat in response to external conditions as part of the building envelope in regions that regularly experience extreme temperatures. Your home will be healthier, cozier, and more effective if it has a building envelope that is sensitive to its surroundings and responsive to those changes.
Finish And Visual Appeal
The ideal house is one that not only looks elegant but also operates in harmony with its surroundings. Both form and function should be considered when finishing a building envelope. A beautiful finish will always raise the value of your home, and it is a wonderful feeling to come home to one. Just keep in mind that there may be limitations on the use of particular exterior paint colors and novel contemporary designs in some areas.
Function
The envelope of a building performs numerous tasks. Three categories can be used to group these functions:[2]
- Support: to ensure strength and rigidity; providing structural support against internal and external loads and forces.
- Control: to control the exchange of water, air, condensation and heat between the interior and exterior of the building.
- Finish: this is for aesthetic purposes. to perform support and control duties while maintaining the aesthetic appeal of the building.
Functions Of A Building Envelope
Utilizing the most recent building technologies, a building envelope’s three primary purposes are to support the structure, provide climate control, and finish the building aesthetically.
Structural Support
The walls of the structure are part of the building envelope, so it needs to be strong enough to support the building and maintain its structural integrity.
The walls must be load-bearing and the foundation must be strong enough to support the weight of the building. The building’s exterior and foundation support must adhere to local building codes.
Climate Control
Another important role of the building envelope is climate control. As was already mentioned, the envelope works to prevent energy loss by ensuring that conditioned air—whether heated or cooled—remains inside and outside air stays outside.
Each building envelope’s design is frequently influenced by the local climate. In comparison to a building in a warm, humid climate, a structure in a cold climate, for instance, requires more protection from the infiltration of cold air.
Finish
What does “finish” mean? curb appeal. All structures, whether they are commercial, residential, or industrial, need to keep their exteriors looking good.
The building envelope, which comprises the exterior of the structure, should therefore be created with appropriate aesthetics in mind. The building envelope must conform to any requirements for a location’s buildings’ exterior design in addition to providing structural support and climate control.
Components Of A Building Envelope
A structure’s exterior performance standards are designed to be met by the functional requirements of a building envelope. The foundation, walls, air, movement, acoustics, durability, and energy are some of the building material-based elements that make up the building envelope.
Foundation
Concrete walls, footings, and slabs are frequently used to construct a building’s foundation. The foundation’s job is to transfer the weight of a building to the ground below.
The foundation, which is a component of the building envelope, must provide moisture control (have waterproofing and suitable drainage), as well as shield the interior from thermal energy.
Walls
Because they offer support, restraint, and finishing, walls are a crucial component of a building envelope.
The necessary support is created by the structural elements of the exterior walls. Wall system components that control thermal energy as well as help walls resist moisture and condensation include insulation, exterior cladding and sheathing, a vapor barrier, and interior sheathing.
Air
Building envelope airtightness needs to be taken into account and managed in a structure. The envelope becomes more loosened as more air enters the interior space from the exterior, which can lead to the previously mentioned heating and cooling issues.
Membranes, spray foams, sealants, and sheathing are a few remedies for air leakage. Up to 20% of the energy used for heating and cooling a building can be attributed to these air barrier solutions.
Movement
Every structure is mobile. Buildings move as a result of ground shifting, changing weather, and temperature changes. These movements need to be possible within the building envelope.
An overly rigid building envelope (i.e., walls and foundations that allow no differential movement) can result in cracks and failure under smaller stresses than a more flexible structure would.
Acoustics
For the comfort of the occupants, a building’s envelope performs more functions than just assisting in climate control. In addition, the envelope must be soundproofed from outside noise.
The building’s attenuated acoustics allow occupants to conduct business or live there without as much interruption from the outside world.
Durability
It’s important that the building envelope last. The elements of the envelope must last because they are an essential part of the building’s structural integrity.
Placement of windows, doors, and the like should consider both aesthetics and functionality. Yes, the building envelope’s components need to look good in addition to giving the structure the strength and support it requires.
Energy
Energy consumption must be taken into account when building today. This covers both new construction and retrofits.
Energy loss through the building envelope is avoided by energy-efficient building design. Radiation, convection, and conduction must all be blocked by the envelope in order to prevent thermal transfer.
Energy-efficient construction and renovation result in more comfortable, economical, and environmentally friendly buildings.
Conclusion
Climate, structural integrity, and energy efficiency of a building are all significantly influenced by the building envelope.
To keep inside-conditioned air inside and outside air and heat (or cold) out, the foundation, walls, windows, doors, and other barrier materials cooperate.
By shielding the structure from moisture and movement damage, the strength and flexibility of the materials used help the structure last.
The last benefit is that a strong building envelope uses less energy, which is advantageous for environmental sustainability and offers building owners additional energy savings.
