New secure premises were urgently needed for the British Embassy in Georgia as it was housed in a hotel in the centre of Tbilisi. Our building services engineers collaborated with Wilford Schupp Architects on a competition entry concept design for a new embassy and ambassador’s residence. Ramboll was subsequently appointed to undertake the detailed design for all building services.
Located on the outskirts of the city, the site was formerly occupied by a hospital, and a gas main and water pipes had to be relocated. Major earthworks allow the 1,600 sq m building complex — a stacked basalt stone plinth structure — to sit firmly in the steep slope with a 30m bomb-blast security perimeter. Unusually, the 250 sq m official residence is located above the embassy, with access to the timber-decked roof of the structure below.
Although linked by a small elevator, the need for energy efficiency and security led to the provision of independent services for the two areas. The heavy thermal mass of the embassy, assisted by automated blinds, provides passive cooling even with the extreme annual temperature range of Georgia. Patterned metal screens encircle the residence above, providing shading and privacy. The residence is naturally ventilated, while the offices employ ceiling-mounted fan cooling units.
Services throughout have been designed to ensure equipment is hidden or disguised, as the location is exposed and high profile. The plant room is almost underground, at the rear of the complex, requiring challenging service routes up the building and across floor plates. Chillers are sunk below the level of the landscape adjacent to the underground car park. A solar thermal system, hidden by screens on top of the residence, is expected to meet half the annual hot water demand for the entire building. This is complemented by gas fired boilers. Several innovative ideas from the concept design had to be ruled out for security reasons, but the project expects to achieve a BREEAM ‘Excellent’ rating.