Case Study // GCHQ


GCHQ is a British intelligence agency responsible for providing signals intelligence information to the British GCHQ is a British intelligence agency responsible for providing signals intelligence information to the British Government and armed forces. Based in the suburbs of Cheltenham, GCHQ was originally established after the First World War and moved to the outskirts of Cheltenham; setting up two sites – Oakley and Benhall. The two sites were subject to a considerable terrorism threat post the ‘cold war’. This resulted in the development of the iconic ‘doughnut building’ which was part of an overall re-development which saw the demolition of both GCHQ’s Oakley and Benhall sites. The re-development at the time was considered to be the second largest public sector development in Europe, with an estimated cost of £337,000,000.


As part of the re-development scheme, Erith were employed to carry out the demolition of a number of H-type and other significant structures situated in Cheltenham, Gloucestershire. The two sites comprised of a number of H-type, low rise, reinforced concrete structures. The concrete and partial brick construction consisted of asphalt panels and steel window frames. Erith’s services throughout the project included the following activities:

  • Strip-out of all non-structural elements
  • Removal of Asbestos Containing Materials
  • Structural demolition
  • Removal of all foundations and concrete raft slab
  • Drainage and service removal


In line with Erith’s on-going commitment to sustainability, Erith were able to divert material from landfill through the use of recycling. 98% of all demolition arisings were crushed and processed to produce geotechnical infill of existing voids on site. Dust, noise and vibration monitoring was carried out through the duration of the contract to help monitor our results and implement innovative measures of reduction wherever practically possible. Examples of implementations include the use of fine mist spray for dust suppression and the use of hydraulic munchers to minimise noise as opposed to the conventional means of breaker attachments.

Health and Safety

To ensure the contract was conducted in a safe and seamless manner, Erith ensured a full time Health and Safety Advisor was situated on site. In our commitment to delivering a best practice approach, we also employed Health and Safety consultants (The Health and Safety People) to undertake external audits fortnightly.

Segregated working perimeters were situated across sites to enable safe and segregated working parameters. Daily Pre and Post Job briefings were undertaken throughout the contract to ensure collaboration and communication on daily task activities. This process allowed workforce to share best practice methods and identify and mitigate any potential risks.

Engineering complexities

During the structural demolition it was identified that asbestos cement sheets had been utilised as formwork to the existing ground slab and would have not been identified within the type 2 asbestos survey. As a result, Erith were able to deploy our in-house asbestos removal division to undertake site investigations, identifying and removing any asbestos containing materials found within the in-situ formwork. The use of our in-house asbestos removal team ensured Erith’s programme did not overrun.

GCHQ at Cheltenham, Gloucestershire



 Project Goals

  • No reportable health, safety or environmental incidents or accident
  • 97.4% of all demolition arising’s recycled
  • Project completed within contract programme
  • Project completed within contract budget