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.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
Guidance notes to prepare for April ERA changes
From the Electrical Contractors' Association Employee Relations team.
Significant changes to be seen from the new ERA in 2026 and 2027, starting on 6 April 2026.
First aid in the modern workplace with St John Ambulance.
Ireland's National Residential Retrofit Plan
Staged initiatives introduced step by step.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.
Reflecting on the work of the CIOB Academy
Looking back on 2025 and where it's going next.
Procurement in construction: Knowledge hub
Brief, overview, key articles and over 1000 more covering procurement.
Sir John Betjeman’s love of Victorian church architecture.
Exchange for Change for UK deposit return scheme
The UK Deposit Management Organisation established to deliver Deposit Return Scheme unveils trading name.
A guide to integrating heat pumps
As the Future Homes Standard approaches Future Homes Hub publishes hints and tips for Architects and Architectural Technologists.
BSR as a standalone body; statements, key roles, context
Statements from key figures in key and changing roles.
Resident engagement as the key to successful retrofits
Retrofit is about people, not just buildings, from early starts to beyond handover.






















