This stage is to develop the technical information of how the project will be built and is usually undertaken after planning permission is granted.   

Stages 3 and 4 tend to run concurrently for the sake of efficiency and in speeding up the process but can be separated depending on the service to be provided.

During this stage other consultants such as structural engineers become more involved. The building fabric and performance are developed and finalised so these can achieve clearnace on Builing Regulation Plan Scrutiny, assessed against the Approved Documents so all comply with curent builing codes. Other consultants may be required for the preparation of  SAP calculations which may be asked for in approving the thermal performance of the building as an example.

Target stage 3  : is a submission for Building Regulations Plan Scrutiny Approval.