Plans for the main leisure centre complex comprise two swimming pools, sports hall, library, fitness suite, aerobics studio, cafГ© and external multi-use games area (MUGA).
The ВЈ2m gym contract was awarded, as a вЂmajor variationвЂ™ to the main works by The London Borough of Hillingdon in January.
Work will start immediately. Completion is due by Christmas 2009.
Martin Smout, chairman and chief executive said: вЂњGB was awarded this work due to the high quality of the work already being done on the site and our solutions-focused way of delivering our projects.
вЂњThe completion of the Botwell Leisure Centre will result in GB having built 11 swimming pools and five leisure centres in just three years.вЂќ
Businesses cut back on tech buys
ISG strengthens forward orderbook to ВЈ350m