Building fabric

The fabric, or envelope, of a Passivhaus needs to achieve high thermal and airtight performance whilst providing structural stability and weather protection. For building durability the design also needs to eliminate the danger of interstitial condensation forming within the structure. This section looks at general principles to consider regarding design and construction of the building fabric.

All construction types can achieve the Passivhaus standard. The decision over construction type often comes down to:

• building form and planning restrictions

• ease of achieving a good thermal envelope

• cost restraints, buildability, speed, material availability, risk, client preference and local skills

Good Practice Guide to Insulation

Passivhaus buildings are known to eliminate the performance gap, and insulation is a crucial element to the fabric first approach. This guide aims to give building professionals an insight into good practice for designing, procuring, storing...

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In a timber frame wall construction, the windtight layer (also known as the breather membrane) can be a rigid board or membrane, which will need taping to eliminate thermal bypass. Modern ‘vapour open’ but windtight and water-resistant...

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In general terms, the more mass there is within the thermal envelope the easier it is to control the possibility of overheating in summer months. A building with high thermal mass, exposed internally, will tend to have even temperatures and a...

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The Building Fabric Thermal Performance of Passivhaus Dwellings—Does It Do What It Says on the Tin?

The Passivhaus (or Passive House) Standard is one of the world’s most widely known voluntary energy performance standards. For a dwelling to achieve the Standard and be granted Certification, the building fabric requires careful design and detailing, high levels of thermal insulation, building...

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Ancon Building Products
Teplo Cavity Wall Ties

Ancon Teplo Low Thermal Conductivity Wall Ties suit cavities up to 450mm and minimise heat loss through thermal bridging, improving the energy efficiency of a masonry cavity wall. Ideal for today’s super-insulated building envelopes,...

Product certification:
BBA Certificate No. 14/5160
Featured project:
Steel Farm
Green Building Store
Compacfoam Compacfoam 200

Specialist rigid thermoplastic insulation used for thermal bridging detailing, including at window & door thresholds.

• Strong lightweight rigid insulation made from thermoplastic foam, based on polystyrene.

...
Product certification:
N/A
Featured project:
Homes for Exeter City Council

Comprises 142 or 172 mm thick structural insulated panels (SIPs) connected with a unique jointing system for walls and roofs, and intermediate floors using I-beams or open web joists.

Product certification:
N/A
Featured project:
The Greenhauses, London
Kingspan
Kooltherm K118 Insulated Plasterboard

Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance, lower lambda internal wall insulation, with a fibre-free rigid thermoset phenolic core. It has a 12.5mm plasterboard bonded to its front surface and a composite foil...

Product certification:
N/A
Featured project:
N/A