Last edited 10 Nov 2020

Occupation and defects liability period

The process for completing the design and construction of a building is often divided into stages. This can be helpful in establishing milestones for the submission of progress reports, the preparation of information for approval, client gateways, and for making payments. However there is a great deal of ambiguity between the naming of stages by different organisations and the definition of what individual stages actually include (see comparison of work stages) and so it is important that appointment documents make it clear specifically what activities fall within which stage, and what level of detail is required.

Within the Designing Buildings Wiki project plans, the stage, ‘occupation and defects liability period’ follows practical completion. It is the stage after the client has taken possession of the development for occupation when any defects are rectified.

On large projects the contractor may set up a hot desk for responding to any complaints or to provide assistance required by the incoming occupants. As the development is now occupied, and the contractor no longer has possession of the site, close co-operation is required between the contractor and the client so as so not to disturb occupants, whose activities will take priority over work required to rectify defects. This may involve out of office hours working.

At the end of the defects liability period, the contract administrator arranges inspections of the works and prepares a schedule of remaining defects and agrees the programme for their rectification with the client and contractor. The contract administrator then arranges final inspections of the works and if satisfied issues the certificate of making good defects. A final report and final account will be prepared and the final certificate issued signifying that the construction works have been fully completed. Any remaining retention is released.

Issuing the final certificate will normally signify the end of the consultant teams appointments. If post-occupancy evaluation services are required, these may involve a new appointment.

The occupation and defects liability period is analogous to the ‘Handover and close out’ stage of the RIBA Plan of Work, (See comparison of work stages), although the RIBA stage also includes post occupancy evaluation.

Within the Designing Buildings Wiki project plans post occupancy evaluation is part of the final stage ‘post occupancy evaluation’. This is the process of determining how successful the delivery of the project was, how successful the completed development is, where there is potential for further improvement, and what lessons can be learned for future projects. It can be particularly valuable to repeat developers and may be a requirement of some funding bodies. In practice, post occupancy evaluation may begin during the defects liability period, and ideally the client should commit to carrying out post occupancy evaluation at the beginning of the project so that appointments and briefing documents can include a requirement to test whether objectives were achieved.