Sustainability is more than just another building industry buzzword. Since April 2007 it has been mandatory for publicly funded homes in England to meet strict new standards set out in the Government’s ‘Code for Sustainable Homes’. The new Code replaces the EcoHomes scheme and measures a dwelling’s sustainability across six key design categories, including the materials used to build it. Peter Sach, Technical Director of Durisol UK, developer of the innovative and eco-friendly Durisol wall form system, considers the impact of the Code on the choice of construction products and methods for public sector projects.

Few would argue that climate change is a reality and that urgent action is needed if we are to halt or even just limit its damaging effects. The Government’s Climate Change Bill commits to achieving a 60 per cent reduction in the UK’s carbon dioxide emissions by 2050 through various regulatory measures and incentives. There is, however, a serious challenge to this objective in the need to build thousands of new homes to meet rising demand in both the public and private sectors. Clearly this will put further strain on energy resources in terms of construction and use.

Although the rate of house building in the UK has grown in recent years it’s still not keeping pace with requirements. The ongoing housing shortage is helping to push up prices and that, in turn, is boosting the need for more affordable homes. Cutting back on housing development plans is one answer but not a very practical one from either a social or economic point of view. The solution, therefore, has to be to build new homes in a way that minimises their impact on the environment and that’s the main principle behind the Code for Sustainable Homes.

The Code highlights the fact that there’s much more to a sustainable home than fitting low energy light bulbs and switching the television off standby. In order to achieve a truly ‘green’ building the issue of sustainability needs to be considered in the design, method of construction and sourcing of more eco-friendly building materials. Indeed, the production, use and disposal of building materials accounts for significant quantities of energy. BRE and various other bodies believe that manufacturing materials and building on site accounts for 30% of a residential building’s lifetime carbon dioxide emissions. Selecting the right building materials is, therefore, as important as specifying an energy efficient heating system.

The sustainability of materials used for constructing the key elements of a house - the roof, external and internal walls, separating floors and windows - is vital to obtain a high sustainability rating for the whole building. This is measured across a number of factors, including the product’s embedded energy and its life cycle energy rating, typically measured over 60 years. The latter takes account of the product’s environmental impact from the ‘cradle to the grave’ so to speak, including repair and maintenance. It also covers the effect of dismantling or demolishing a building at the end of its life and whether the materials can be recycled, for example.

So that’s the background to the Code and its objectives, but what does it really mean when it comes to choosing materials for building projects, and how do public sector specifiers and contractors ensure that focusing on a product’s sustainability doesn’t compromise other equally important considerations, such as cost, availability and ease and speed of installation?

A sustainable building product must satisfy certain criteria in terms of its production, what it is manufactured from and last but not least its contribution to a building’s overall energy efficiency. In developing Durisol, the original stay-in-place wall form system, I believe we’ve addressed most, if not all these issues. The result is an innovative and durable building solution that can help decrease a building’s carbon footprint whilst also assisting faster build times. The use of recycled material, that is in itself 100% recyclable, is at the heart of a green building product and Durisol interlocking wall units are manufactured from at least 80% FSC recycled waste softwood bonded with proprietary cement. As far as speedier construction is concerned, the interlocking modular units are simply dry-stacked, with no need for mortar or bricklaying skills, and then filled with concrete to create solid walls with excellent thermal and sound insulation. Indeed, as the majority of the insulation is located on the exterior of the concrete core, the units benefit from a high thermal mass which contributes to lower energy requirements.

Durisol has also just made its range even greener with the introduction of new wall form units with integrated Rockwool mineral fibre insulation, a green material in itself which enables U-values as low as 0.21 plus a noise reduction coefficient for sound absorption as high as 0.95, without additional insulation or finishes. Life cycle costs have also been considered in the development of the Durisol wall form system. The units are very durable and will not rot or decay. They are also resistant to damage from vermin and wood boring insects and do not support fungal or bacterial growth.

In conclusion, we must now accept that sustainable building is no longer simply a desirable option, it’s a necessity. Adopting an environmentally responsible attitude towards the specification, design and construction of a building can have a positive environmental effect all through the life cycle of that building, whether it’s a house or a hospital. As demonstrated in the development of our wall form system, Durisol believes materials’ manufacturers can play an important role in developing green solutions that not only satisfy increasingly stringent environmental standards, but which also deliver the cost savings and construction efficiencies necessary to create more affordable homes.