Summary
• Timber windows can contribute to a rating of Level 4-6 in the Code for Sustainable Homes.
• The housing downturn means more focus on public sector projects.
• NorDan’s Academic Brochure carries information on windows’ life cycle assessments and embodied energy.
• Its NTech Passive windows have been used in three houses in the BRE Innovation Park.

Sustainability and zero carbon homes are no longer just on the wish list when specifying a project, they are key to achieving compliance.

While PVCu remains popular, discerning developers and architects are now specifying timber, particularly those looking to achieve Level 4-6 of the Code for Sustainable Homes and enquiries for aluminium-clad timber windows, which tend to be more thermally efficient, are certainly on the increase.

With the downturn in the housing market, many contractors are focusing on social housing and other public sector build projects such as schools. This is a key area where there is usually a high specification of sustainability and energy saving – a good sign for timber windows.

This sector also tends to put a strong emphasis on maintenance and security, and some local authorities and housing associations are already asking for Level 3 or above on planning applications and looking at the whole life cycle cost of a product. With a building’s greatest energy loss through its windows, very low U-value, high performance timber windows must be the answer.

Architects also need to be asking questions related to timber sourcing: is the timber from well-managed forests and does a company have certification from organisations such as the Programme for the Endorsement of Forest Certification or the Forest Stewardship Council?

The terms ‘performance’, ‘sustainability’ and ‘energy saving’ should apply to a window, not only on installation, but over the whole product’s life span. This means considering the true embodied energy of a window, from how raw materials are produced and how much energy is used in the manufacturing process through to finished product, as well as energy used in transport.

This is an area NorDan feels passionately about, and we have invested heavily in research from leading construction and environmental academics to review and learn from the latest thinking on embodied energy and life cycle assessments. Our detailed Academic Brochure, which pulls together the latest research, is available via the NorDan website and there has been a lot of interest from architects and specifiers keen to make more informed choices when working on a project.

For example, the NorDan triple-glazed NTech Passive with its low U-value of 0.7W/m2K created a lot of interest after it featured in the Kingspan Lighthouse and Stewart Milne Group Sigma home at the BRE Offsite exhibition last year and has been specified for the Barratt Green House. Its low U-value makes it possible to reduce the energy used and the amount of building material in new houses without making a compromise with Building Regulations and the Code for Sustainable Homes. The result is lower expenses, lower energy consumption and a healthier indoor climate with the maximum contribution to zero carbon.

This was achieved by NorDan’s development of a highly-efficient, environmentally-friendly insulation board, combined with high-performance glazing and new warm edge technology with a much lower thermal conductivity. A further development was the removal of the trickle vent on the NTech range in line with Passivhaus recommendations.

Two schools have recently specified and installed NorDan windows. The new-build £1.9m four-classroom Mickleton Primary School in the Cotswolds had a range of specifications from safety and security, ease of maintenance, bright colours and a traditional appearance.

Natural ventilation and light were needed but also high levels of insulation. Gloucestershire County Council opted for NorDan inward-opening three-handle tilt-and-turn windows which offer good security, are easy to clean from the inside and give good weather performance. And because of the windows’ insulation it was possible to specify larger windows without compromising on energy efficiency.

NorDan tilt-and-turn timber and aluminium-clad windows and doors were specified for the £7.7m three-storey Winston Way Primary School in Redbridge near Ilford. Built as part of the government’s Building Schools for the Future initiative, the project included classroom windows, ground floor screens and doors out into play areas, plus full height fixed glazing units for the administration block.

Vandal-proof safety glass also addressed noise pollution concerns from the nearby busy main road. The whole job was supplied and installed within 12 weeks.