Modern methods of construction (MMC) are helping to address the need for more affordable homes that satisfy increasingly stringent sustainability standards, says Peter Sach of Durisol, the developer of the innovative Durisol wall form system.

The term MMC embraces a range of technologies and supply chain specifications to achieve high quality, well-designed buildings, more quickly and at lower cost. It includes techniques such as prefabrication and off-site assembly, and also promotes the use of sustainable building materials to ensure that a structure is resource efficient during construction and beyond. MMC is used increasingly in both the public and private sectors as a means of improving construction quality, efficiency, and site safety. It also reduces time spent on site, which cuts labour costs and minimises disruption, and addresses current skills shortages in the building sector. Given these many important benefits, MMC can, and is already, playing a key role in meeting demand for more social housing in a shorter time, without compromising issues such as thermal efficiency and sustainability.

Various Government initiatives are encouraging greater construction efficiencies, and the use of MMC, to assist in the building of quality homes at less cost and in less time compared with using established construction methods. These include the new Code for Sustainable Homes and the Design for Manufacture Competition, which feature several MMC solutions in the challenge to build a high quality eco-home for a capital cost of £60,000.

The development of Durisol, the original stay-in-place wall form system, encompasses the core benefits of MMC for private and public building projects. The system provides a durable, eco-friendly solution for interior and exterior walls and can help reduce a building’s carbon footprint, whilst also enabling faster build times.

Let’s look at the issue of speedier construction first - one of the key advantages associated with MMC. The Durisol system consists of interlocking hollow modular units manufactured from at least 80% FSC recycled waste softwood bonded with a proprietary cement/PFA (Pulverised Fuel Ash) mix. 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. This unique approach to wall forming is fully Part L compliant, has low embedded energy and is fully recyclable. Solid walls can be built in a fraction of the time it would take using traditional masonry methods. Drylining and fittings are attached with nails or screws, and the open surface texture provides an ideal substrate for plaster.

Durisol units can be used above and below ground, and their light weight means that individual wall form units can be quite large and still be easily handled by one person. This means that fewer units are used per wall than with traditional masonry components, which reduces construction time still further.

In addition Durisol wall form units are available with the exterior side of the cavity factory-filled with Rockwool insulation. This saves yet more time on site, and creates thermal performance up to twice that of a conventional wall with a high thermal mass which keeps the building in a thermal 'steady-state' and reduces the need for cooling and heating in the day-night cycle (and also in the summer-winter cycle). Durisol units with integrated Rockwool mineral fibre insulation create a wall with 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 on site. In addition, the Durisol wall form system uses no petrochemicals with no potential for off-gassing.

Modern methods of construction are also about using products that are themselves more eco-friendly, and which enhance the durability and lifetime running costs of a building. Durisol wall form units are so rugged that the infill mix can use recycled aggregates in a high slump concrete. And the casing of Durisol material is both a vapour barrier and a breathable membrane – which does away with the need to wrap the entire building in a film. Life cycle costs have also been considered in the development of Durisol. 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.

Modern methods of construction and associated building innovations, like the Durisol wall form system, are now widely regarded as an effective way for the construction industry to improve quality, enhance efficiency and achieve greater speed of delivery and sustainability. Given the many proven benefits, this is clearly the way forward if we are to meet current and future building demands.