With looming government regulations and an economy which appears to be digging its heels in, Housing Associations are facing an increasingly difficult challenge of meeting the demand for sustainable, affordable housing. The housing deficit continues to grow, yet diminishing budgets and tighter regulations are causing headaches for many organisations within the sector. Suppliers and contractors are being forced to consider investing in R&D, essential for developing cost effective, sustainable solutions to meet standards such as the Code for Sustainable Homes, against other key features within a company’s operations. Despite the difficult conditions, Victory Housing Trust, the East Anglia based housing charity, is facing the issue head on, already managing a number of low carbon developments.

Darryl Cox of Victory Housing Trust comments: “Sustainability is high on our agenda, not just for the obvious environmental reasons, but also because we are in the business of providing affordable homes – and that’s not just about the rents, but about the cost of running the home as well. Rising fuel costs mean that energy bills are a big part of a household’s outgoings, so providing efficient homes is an important part of maintaining that affordability factor. The challenge is doing this in a cost-effective way at a time when grant funding for building new homes is being squeezed.”

From a supplier perspective, Stewart Milne Timber Systems appreciates these challenges and is at the forefront of delivering cost-effective, sustainable homes, having worked on numerous low carbon affordable housing projects. Alex Goodfellow, group managing director – Stewart Milne Timber Systems, said: “In the challenging market conditions, it is becoming more and more difficult for Housing Associations to meet the stringent regulations with reduced budgets. Therefore, it is important for them to take a more detailed review of overall project costs alongside energy ones to meet budgets and sustainability requirements. Elements such as speed and simplicity of build, site prelim costs, waste management and onsite predictability can all be optimised when using timber frame to deliver projects cost effectively. Cost benefit is a significant area where we as a company have been particularly successful when working with affordable housing providers”.

Victory and Stewart Milne Timber Systems recently worked together on a sustainable housing development in Snettisham, Norfolk, which is an example of finding the right blend of meeting low carbon regulations while optimising budgets. The initial project brief for contractor, Youngs Homes, was to deliver cost-effectively fifteen Code Level 4 properties that would be of significant long term benefit to occupants. In order to deliver the homes to the necessary standard, Youngs sought to achieve first-class energy saving within build material features, including insulation and air tightness, as well as considerable cost-efficiencies through offsite prefabrication. Other key aspects included the variety of external finishes, window detailing and integration of services. With a diverse range of considerations, there was a requirement for a flexible, sustainable solution to help meet the project specifications. Due to its unrivalled sustainable properties and cost-efficiency potential, the properties were built in timber frame using Stewart Milne Timber Systems’ award winning Sigma II Build System.

Alex Goodfellow, group managing director – Stewart Milne Timber Systems, said: “The challenge of the project was to provide an all-round service which met the necessary performance and budgetary requirements. In order to do so, we worked very closely with all parties, from initial concept design, right through to onsite delivery. The project was completely tailored to the brief and, as well as providing a build system to meet the desired performance levels, we implemented some of our innovative onsite practices, including a scaffold-less erection system, which led to reduced health and safety risks and increased onsite efficiency. Due to our ability to offer cost certainties, we delivered the contract on a fixed price, which allowed the clients to maintain control of costs, and ensured project spend was optimised through the provision of value engineering."

In the first design, manufacture and erect project to utilise the Sigma II Build System, the homes benefitted from vastly improved thermal bridging, air tightness and unique design flexibility. The timber frame was manufactured offsite, offering cost savings and minimising health and safety risks, with the closed wall panels pre-insulated and filled with blown polystyrene beads. The system also featured seals pre-fitted to the top and bottom of wall panels, plus floor cassettes with perimeters pre-insulated and wrapped with airtight membrane, requiring only wall panel to wall panel joints to be taped on site. In terms of energy performance, the properties achieved an air tightness performance of 3m3/h/m2 @ 50pa while the system’s insulation, designed to achieve U-Value of 0.12 W/m2/k with a lambda value of 0.032, provided the homes with high water resistance, long term durability and thermal bypass prevention within the panel cavities. Other performance indicators included air tightness (2) and thermal bridging (0.02), largely thanks to the system’s innovative C-stud technology. As well as meeting the sustainability requirements, the Sigma II Build System was easily integrated into the house designs, demonstrating its flexibility and timber frame’s reputation as one of the most favoured materials in low carbon housing.

Darryl Cox comments: “The benefits to our residents of building sustainable homes is clear: reduced energy bills and a comfortable, warm place to live both have a big impact on their quality of life. And just like everybody else, our residents are concerned about the environment, and they are happy to live in homes which minimise their impact on their carbon footprint.”

Alex Goodfellow, group managing director – Stewart Milne Timber Systems, said: “The project at Snettisham was particularly exciting as it was the first to utilise the Sigma II Build System and, thanks to its technical properties and our close working partnerships with the other parties, we were able to deliver the homes to the desired specifications and, more importantly, cost effectively.”

January 2012