INNOVATION AND THE FUTURE sustainability and carbon-zero houses Recently BRANZ and a Beacon-led industry group visited the BRE Innovation Park near to see how the UK industry is approaching the drive to increase the sustainability of new homes. By Mark Jones, BRANZ Building Performance Manager

o improve the overall sustainability home. The target is that all new housing should speeding up house delivery and more effective of new homes the UK Government be carbon-zero by 2016. use of construction materials. Landscaping launched the Code for Sustainable is included with sustainable drainage, T Homes in late 2006, a national standard BRE Innovation Park bioremediation and biofiltration. for sustainable design and construction. The BRE (Building Research Establishment) has standard gives the UK residential building worked closely with the UK Government in Osborne house built in 2 days industry guidance on designing and constructing developing the code and currently provides The Osborne demonstration house was homes with higher environmental standards. technical support. In 2005, BRE opened constructed before the code was launched. The The code provides an independent their Innovation Park in Watford, just north aim was to create a contemporary and economic assessment and rating for new homes, covering of London, to showcase the latest innovative home with a design that could be adapted for areas such as energy and CO2, water, materials, sustainable construction methods, particularly many types of housing, from detached and surface water run-off, waste, pollution, health those that are cutting-edge, practical and terraced through to 3-storey flats. and wellbeing, management and ecology. It is affordable. The park is sponsored by several The house was built in less than 2 days also designed to assist homebuyers to obtain government departments and partnered by UK using a structural insulated panel system. It better information about the environmental and European construction companies. Other uses a third of the heating and cooling energy impact and potential running costs of houses. industry partners also use the park to showcase required by a conventional house built to the their latest technology. current building regulations. Other features are UK houses carbon-zero by 2016 There are currently seven demonstration a ‘whole house’ heat recovery system and the Earlier this year, the UK Government made it buildings in the park. The houses highlight use of recycled plastic slates. A data delivery mandatory for all new houses to receive a code modern methods of construction and a range system showing energy consumption and live rating from 0 to 6 stars – 1 being just above their of technologies and processes involving public transport information is part of the smart current building code and 6 being a carbon-zero prefabrication and off-site assembly, all aimed at technology used.

Osborne, Kingspan Lighthouse and ecoTECH Organics houses. Hanson Ecohouse.

46 BUILD December 2008/January 2009 Different styles achieve 4 stars to enable a range of living spaces to be achieved. and development projects. The houses will be The ecoTECH Organics house and the Spaces can be left open or the floors can be monitored over the next 2 years to measure Hanson EcoHouse demonstrate markedly slotted between the frames. The building services performance, thermal comfort levels, air different innovative styles to achieve 4-star are integrated around a platform of renewable and quality characteristics, energy generation and code ratings. sustainable technologies: a biomass boiler, a wind thermal performance. To evaluate the houses’ The ecoTECH Organics house uses integrated catcher, mechanical ventilation with heat recovery, performance when fully occupied, it is intended panels. Designed to make sustainable homes building integrated photovoltaic panels and a solar- that families will live in them for periods of time accessible to more people, this system allows thermal array. The house achieves a zero carbon during the study. for flexible design and construction from studio energy supply for space and water heating using Beacon Pathway are thanked for permission apartments through to 5-bedroom houses. advanced power and water efficiency techniques. to use the photographs in this article and The Hanson EcoHouse uses high levels of Around 30% of the water is from rainwater supplying additional information. thermal mass from prefabricated masonry harvesting or greywater recycling systems. external walls, heavy-weight block internal The Barratt Green house won the 2007 Home partitions, a precast staircase and concrete for the Future design award competition, run floors. The design is based on a traditional by a UK Sunday newspaper. The focus of the brick kiln, with its steeply pitched roof and competition was to design a highly sustainable central chimney. Using convection, hot air is home that could be built by a mainstream volume drawn up the chimney while drawing cooler air builder. The prototype was then constructed within from a lower level. The building can store heat the Innovation Park by Barratt Development PLC. during warm periods and release it when the It is the only home in the park constructed by a temperature drops. mainstream house builder. Both houses have water-saving measures, Together with advanced water efficiency such as low-flow devices, and greywater and recycling technologies similar to the other recycling and filtration systems. The houses houses on site, the Barratt Green house also have also been designed to accommodate other has super-insulation, triple glazing, controlled Insulation panel. technologies (such as photovoltaic panels and ventilation and photovoltaic systems. Other mechanical heat recovery systems) to allow innovative features are computer-controlled them to be upgraded. Such energy-efficiency systems such as shutters, and central enhancements will result in the houses achieving interactive power and data storage facilities to higher code ratings in the future. enable wired/wireless technologies. Achieving 5 stars The Re-thinking School The Stewart Milne Sigma house is a 5-star The Re-thinking School provides for an improved construction. It is designed for higher density learning environment through the flexible and living and focuses on thermal performance, practical use of space combined with excellent the integration of solar thermal, photovoltaic lighting, ventilation and acoustics, and sustainable and micro-wind technologies for generating features. It has high levels of wall, roof and floor renewable energy and effective solar design. It insulation and high performance, low emissivity also uses low water consumption devices and double glazing. A wind turbine provides renewable an inbuilt internal greywater recycling system. energy. The school also has both rainwater and The house is based around a 3-storey Victorian greywater harvesting and water-efficient fittings. terraced house but is arranged over four levels The rooms have semicircular, movable walls that to make them more affordable and minimise can be reconfigured to meet the varying needs the building footprint, allowing 45 units to fit of pupils. into 1 hectare of land. An unusual feature of the Re-thinking School is that the building is designed to be remountable Net-zero carbon homes and could be dismantled and rebuilt elsewhere. The Kingspan Lighthouse and the Barratt Green Retractable, reusable screws and screw piles house achieve the highest code rating of 6 stars, are used for the foundations, which are suitable making them net-zero carbon homes. Both for difficult ground conditions. houses use super-insulation. The Kingspan Lighthouse was designed to R&D on demonstration houses provide generous daylight levels. It has effective Although these are all demonstration buildings, Barratt Green house. solar control and uses a timber portal structure at least two of them are also part of research

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