Oxford Circus House presented a unique challenge.
A 1920’s building with exceptionally low floor-to-ceiling heights, constructed above Oxford Circus Station, required transformation to meet the needs of Transport for London’s Operational Learning Department and further be designed to achieve a "BREEAM EXCELLENT RATING" in accordance with TfL’s requirements.
Design strategies devised to meet the functional requirement whilst reducing the carbon footprint of the building and achieving the BREEAM rating included the incorporation of :-
• Raft ceilings and exposed services. These were employed to create a sense of space despite limited headroom in some locations.
• The installation of 'de-minimus' secondary glazing utilising Low-E glass (to increase air tightness and minimise heat loss through cold radiation).
• Internal insulation to traditional masonry construction external walls (thus reducing the heating and cooling loads generated).
• Smart Building Plant: Due to high local external noise levels, natural ventilation not suitable. Each occupied space provided with mechanical ventilation (12 l/s/p) provided by ECE Type RG heat recovery AHU with high-efficiency inverter driven variable speed fans, providing full fresh air to each space and heat recovery, controlled by CO2 sensors in each room via Trox Technic volume control boxes. Heating and cooling to each space was provided by Mitsubishi “City Multi” VRF heat recovery system.
• Low energy T5 lighting system incorporating daylight dimming and occupancy control systems.
• Low water usage sanitary ware (dual low volume flush wc's and low flow taps etc).
• The maximisation of the re-use of existing structure and fabric; undertaken to minimise waste.
• Selection of products from the 'Green Guide' Product Selector
• Use of Solar Thermal panels for domestic water heating.
• Centralised building controls linked to distributed metering, a fully integrated BMS gives the clients a minute by minute overview of systems' performance.
WPA provided full architectural design and lead consultant services throughout the project, responding to a rigorous low energy brief driven by TfL Group Property and Facilities. The project was even able to install bat boxes in this central London location to assist a somewhat counter intuitive local eco-system.