Building fabric

The term 'building fabric' refers to structural materials, cladding, insulation, finishes, etc., that enclose the interior of a building, separating the internal from the external.

Very broadly, for most buildings, the building fabric will include a number of elements:

• The roof.
• External walls.
• Windows.
• Doors.
• The lowest floor.

Each of these will in turn be assemblies of a number of components.

The building fabric serves to:

• Protect the building occupants from the weather, such as wind, rain, solar radiation, snow, and so on.
• Regulate the indoor environment in terms of temperature, humidity, moisture, and so on.
• Provide privacy for occupants.
• Prevent the transmission of noise.
• Provide security for occupants and the building contents.
• Provide safety, for example preventing the spread of fire or smoke.
• Provide views into and out of the building.
• Provide access between the inside and the outside of the building.

It is also generally a major part of the structure of the building.

As a result, building fabric is now seen much less as just a stylistic add on to a building, but more as a fundamental part of to the way the building operates. Increasingly, this is resulting in the creation of complex, multi layered elements to the building fabric, and the use of modern materials such as high performance glazing, architectural fabrics, active shading, and so on.

The building fabric will usually contain openings as a means of providing physical access, admitting daylight, providing natural or mechanical ventilation, supplying services, allowing drainage, and so on. In some cases, this may conflict with other performance requirements, for example, openings may cause security, privacy or noise nuisance issues. These potential conflicts require careful consideration and design, which may include the use of screens, shades, baffles, and so on.

Junctions between the elements that make up the building fabric can also cause problems, for example creating a cold bridge between the inside and the outside.

Other considerations that might affect the design of the building fabric might include:

• Legislative requirements.
• Performance requirements.
• Site topography.
• Site conditions, such as noise nuisance and air quality.
• Climatic conditions.
• Shading requirements.
• Building type.
• Building services strategies, such as lighting and ventilating strategies.
• Context and stylistic considerations.
• The availability of materials and skills.
• The sustainability of materials.
• Maintenance and cleaning.
• Other requirements, such as the photovoltaics, rainwater run off or storage, landscaping, and so on.
• Durability, flexibility and expected life.
• Deconstructability and recyclability.

Good design can allow for reductions in heating and cooling loads, lower energy use and lower carbon emissions. This can mean there is a trade off between the capital cost of the building fabric, the capital cost of building services, and the operating cost of the building.

It can be more challenging to improve the performance of existing buildings. However, retrofitting can include improvements to air tightness, the introduction of double glazing, the installation of cavity wall insulation or internal or external solid wall insulation, and so on.

NB Conservation Principles, Guidance for the sustainable management of the historic environment in Northern Ireland, published by the Historic Environment Division in July 2021, defines fabric as: ‘The material substance of which places are formed, including geology, archaeological deposits, structures and buildings, construction materials, decorative details and finishes and planted or managed flora.’

Assessing risks in insulation retrofits using hygrothermal software tools, Heat and moisture transport in internally insulated stone walls, by Joseph Little, Calina Ferraro and Beñat Arregi, published by Historic Environment Scotland in 2015, defines building fabric as: ‘The sum of the structural, fixed materials of which the building is made. This contrasts with furnishings which are loose.’

[edit] Related articles on Designing Buildings

• Airtight.
• Building regulations.
• Cavity wall insulation.
• Cladding.
• Conduction.
• Convection.
• Curtain wall systems.
• Curved glass.
• Damp in buildings.
• Fabric first investigation into net zero for existing buildings.
• Façade.
• Glazing.
• Infill panel walls.
• Insulation.
• Insulation for ground floors.
• Kinetic facade.
• Load-bearing wall.
• Louvre specifications.
• Metal profile cladding.
• Passive building design.
• Sandwich panel.
• Solar gain.
• Thatch roofing.
• The building as climate modifier.
• Thermal bridge.
• Thermal imaging of the building fabric in the net zero world.
• Upcycling buildings.
• U value.
• Wall types.
• Weathertight.
• What are walls made of?

[edit] External references

• New-learn - Building fabric