シャープ　太陽光発電システム（「イギリス・環境庁」篇）　ナレーター：吉永小百合

Red Kite House 　Thames Region 　Environment Agency　UK

Howbery Park, Wallingford, Oxfordshire, UK

Red Kite House is a new office for the Environment Agency. It is an example of sustainable development that demonstrates our leadership in the design of improved workplaces. We hope that it will help raise awareness for the potential for businesses, organisations and the public to make positive choices to protect and improve the environment.

The Environment Agency's West Area headquarters has been based at Howbery Park since 1993. Until Red Kite House was built, 250 staff working for the area were dispersed between eight different buildings. The buildings lacked internal flexibility, they were inefficient in their use of energy and water, and the distances between them hampered effective and efficient team work. We made a decision to move into a single building that offered more flexibility and was more efficient in its use of resources.

HR Wallingford Ltd. obtained planning permission to redevelop part of Howbery Park as a business/science park and construct 11,750-sqare metres of new office space. After evaluating a range of options, we agreed to lease one of the new office buildings for a period of 15 years.

The Howbery Park site was favoured because of the competitive lease terms, minimal business disruption, a beautiful parkland situation next to the River Thames and the site owners/developers allowing us to influence the design of the building. From the very start of the design process we worked closely with HR Wallingford Ltd. and their team of architects, designers and engineers. The agreed aim was to construct an office that would not only meet our operational needs but would also serve as an example of best practice in sustainable office development.

The basic building had to achieve a BREEAM "excellent" rating to meet the requirements set out in the Agreement for Lease. It was agreed that the office would be a three-storey, naturally-ventilated building with an internal floor area of approximately 3000 square metres. This was the area calculated as necessary to meet our requirements while improving the working environment through more flexible working settings.

Moss Construction of Newbury, a division of Kier Regional Limited, was awarded a design and build contract of approximately £4.5 million to construct the building. Moss worked closely with the design team and us to ensure a successful outcome to the project, especially in terms of the environmental matters.

Environmental features

Natural ventilation and cooling mechanisms

• Red Kite House is naturally ventilated and relies on thoughtful and innovative design features to provide the cooling required. The building is a curved shape and is orientated to capture the wind. This maximises airflow through the building and this supports the cooling processes.
• Manually operated window openings provide natural cross ventilation.
• High-level exposed concrete ceilings on each floor act as a heat sink during the day. They are cooled by air entering through 100 motorized windows on each floor.
• Roof-mounted turbines draw air in through the windows on the top floor, which is the most vulnerable floor to overheating in the summer.
• Neutral solar control glass minimises solar heat gain in summer whilst maximising natural daylight.
• The south-facing canopy provides external shading, especially to the top floor.

Energy

• Photo-voltaic cells that generate electrical power make up the south-facing canopy. They will reduce the amount of carbon dioxide being discharged to the atmosphere by about 12 tonnes per year.

The solar arrays installed are made up of a total of 316 Sharp 80W PV modules designed and supplied by solarcentury.

• Solar thermal panels to provide hot water have been installed on the roof. They will reduce the amount of carbon dioxide being discharged to the atmosphere by a further 1.6 tonnes per year.
• The building, in operation, is expected to have carbon emissions 26% below that defined in the Department of the Environment's "Good Practice" guidance.

Water and drainage

• A rainwater harvesting system to collect and re-use rainwater has been installed. This system collects rainwater from the roof for re-use within the building. This system will satisfy about 40% of the building’s annual demand for water. Overspill from the tank is directed into a reed bed.
• We are actively promoting more sustainable forms of drainage from all developments in order to reduce the impact of run-off on river systems. The 94-space car park uses pervious blocks, which allow rainwater to soak through into the ground. A geotextile membrane below the blocks traps oil and other pollutants.

Anticipated environmental benefits and savings