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Solving energy efficiency through the building fabric

Increased knowledge sharing across the supply chain would help tackle new energy efficiency policies, says Robert Cridford, technical manager at Siniat

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Two major energy efficiency policy updates are changing the way buildings are designed and refurbished. Under the government’s minimum energy efficiency standards, all domestic and commercial properties to be rented in England and Wales will need to achieve at least an ‘E’ rating on their energy performance certificate from 1 April 2018. 

The standards apply to all rented properties, old and new. For new builds, this will mean paying close attention to energy performance throughout the design process. Retrofit projects will need careful planning to meet the standards without spiralling cost implications.     

New energy efficiency policy was also introduced for homes in the capital in October last year. London’s commercial and residential buildings have long had to meet standards that are 35% stricter than the minimum for Part L of Building Regulations: Conservation of fuel and power. The GLA’s London Plan now stipulates that all new residential developments with ten or more dwellings must comply with zero carbon requirements, or make a yearly offset payment of £60 per tonne of carbon dioxide into a ring-fenced local authority pot. 

Whist the regulations only currently apply to specific regions or sections of the market, wider roll out is likely to be a matter of time as policymakers continue the shift towards a genuinely sustainable built environment.


Robert Cridford, technical manager at Siniat, explains that boosting the energy efficiency of the built environment will require a holistic approach across the design and construction sectors. It needs to incorporate a wide range of measures, from encouraging behavioural changes by occupiers to implementing new smart technologies to help manage energy use. But the way buildings are designed, constructed and refurbished will play a fundamental part.

Crucially, closer attention needs to be paid to building fabric. This must be centred on two key considerations: first, improving thermal insulation and second, air tightness.

Increasing thermal efficiency is all about using the best materials for the project. For example, says Cridford, using the right kind of plasterboard to insulate ceilings and partitions can significantly reduce energy use. For new-build commercial and residential projects, this is ultimately about encouraging greater knowledge sharing and collaboration across the supply chain. In particular, the expertise of materials providers must be shared with designers and specifiers from the start of the design process.

In the case of retrofit schemes, this will mean suppliers can advise on the most cost-effective solutions to meet higher efficiency standards but also other technical considerations that need to be kept in mind during any upgrade or change-of-use works, such as fire protection.

In turn, materials providers need to drive innovation, investing in research and development programmes to come to the table with new and improved solutions. Siniat, an Etex Building Performance company, is trialling new drywall materials at its specialist R&D centre in Avignon, France.


Increasing the air tightness of a building’s fabric is the second step to greater energy efficiency. A traditional air tightness target for developments is 10 cubic metres of air per hour per square metre of external building envelope (10m3/(h.m2)@50Pa). Cridford suggests that this should be further reduced to around two cubic metres per hour.

A more open and inclusive approach across the supply chain is again vital to getting this right and materials providers need to share their expertise. Siniat has created a gypsum sheathing board as an alternative to cement particle boards to improve air permeability. Traditional cement boards can expand and contract by up to 1.5mm per metre in different weather conditions, leading to air leakage. In contrast, Siniat’s Weather Defence provides an effective primary air-seal for the building envelope which consistently achieves less than (1.5m3/(h.m2)@50Pa). 

Siniat's technical teams are now working to share this knowledge and further industry understanding. The installation process for any building product also needs to be up to scratch and it is incumbent upon installers to make sure they are following accredited systems. 

Improving thermal efficiency and air tightness are just two elements of improving energy efficiency in new and existing buildings. Implementing these advances simply requires a change of approach and more enlightened thinking.

For more information and technical support visit:



Susie Smallridge

01275 377467



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