黑洞社区

Making existing buildings more energy efficient is one of the biggest challenges facing occupiers, government and the industry today. Just over 1% of the built environment is replaced each year, which means reducing carbon emissions can only be achieved by significantly improving building that are already there. This is why two years ago 黑洞社区 launched its 99% campaign, which called for action to improve existing stock.

But this is easier said than done. Upping the energy performance of existing buildings is particularly difficult because many are very leaky, barely insulated, single glazed and burdened by clapped out services. The archaic construction methods originally used for many of them makes updating even more tricky. Adding insulation to solid walls, for example, either makes internal spaces smaller or changes the external appearance of a building.

The 黑洞社区 99% Campaign award for refurbishment recognises teams that successfully overcame these challenges to produce energy-efficient buildings fit for the 21st century. Here we present the six entries that made it onto our shortlist including the winner Axis Design.

Axis Design, Ecoterrace

There is a lot of Victorian terraced housing around, and its poor energy performance makes finding ways of improving it particularly pressing. Architect Axis Design teamed up with Staffordshire Housing Association and two councils to do just that. The team took a row of six Victorian homes and improved their energy performance from a rock bottom EPC rating of G up to an A. Common methods were uses, such as adding insulation in the walls, under the floor and in the roof, high-performance windows and a high-efficiency heating system. What was most radical was that at the back, single-storey additions were replaced by sunspaces intended to maximise solar gain and improve daylight levels inside. These improvements have cut energy bills from 拢800-1,200 to 拢200.

3D Reid, Marks & Spencer store

Supermarkets have made a lot of noise about greening their property portfolios, which mainly means upgrading existing buildings.

To that end, retail giant Marks & Spencer engaged architect 3D Reid to upgrade a 70-year-old store in Bournemouth. Improvements to the building fabric included adding glazed lobbies and insulated display windows to the building to improve thermal performance and airtightness. A green roof was installed to increase biodiversity on the site.

A-rated materials from the BRE Green Guide to Specification were used where possible and water-saving taps and toilets have also been specified. The result was that the building, which uses 25% less energy than before, achieved a BREEAM 鈥渧ery good鈥� rating.

Tentigo Design, zero-carbon loft conversion

The energy performance of an existing Victorian terraced house has been significantly enhanced by the addition of a zero-carbon loft extension. Its specification is as radical as its appearance; it has well-insulated fabric, high performance glazing, a mechanical ventilation system with heat recovery, and phase change materials in the walls and ceilings to give it the same thermal mass as 90mm of concrete. It also has a wind turbine and greywater recycling facilities.

Because the loft extension increases the floor area by 50%, this means total energy and water use per square metre in the building should be cut by half. The project will be monitored to see if it delivers on these predictions.

Cundall, 50 Queen Anne鈥檚 Gate

At a cost of 拢100m, Cundall have upgraded a late seventies office building so it complies with the 2002 version of Part L. Improvements to the envelope include installing high-performance glazing and insulation. Energy-efficient lighting that incorporates movement and daylight sensors has also been specified. The M&E package includes high-efficiency boilers, chilled beams and heat recovery devices on the air handling plant. More than half the existing facade and 80% of the structure was retained.

Morgan Lovell, London office

When office refurbishment and fit-out specialist Morgan Lovell needed to refurbish its sixties London office it decided to make it an exemplar of what can be done to improve existing buildings. It teamed up with BRE to use the project as a test bed for the development of the BREEAM office fit-out method, and achieved a final score of 76%, which gave it an 鈥渆xcellent鈥� rating. Materials were carefully considered, for example, kitchen work surfaces were made from recycled plastic bottles and the entrance mats from old car tyres. Clay-based paints were used on the walls to cut down on solvent pollution. Efficient M&E features were specified, including dimmers that automatically adjust lighting and light sensors that shut off water supply to the toilets when unoccupied.

Simons Group, head office

Simons Group wanted to demonstrate that the environmental credentials of a head-office building could be significantly improved within normal commercial constraints. It decided to do so on a seventies office building in Lincoln, where it was responsible for design and refurbishment. It improved the performance of the building fabric by 20% above the 2002 version of Part L, installed efficient plant and lighting, and a rainwater harvesting systems. The building was designed to have an energy use of 174kWhr per year which compares well with 225kWhr per year that the Carbon Trust defines as a good practice building.