Sectional completion and the retention nobody releases
A section handed over in March should not be waiting on a contract that finishes in November. In practice it usually is, because the spreadsheet has one completion date.
QScope Team · 18 December 2025 · 5 min read
Sectional completion is used wherever the employer needs part of the works before the rest: a school taking classrooms block by block, a retail unit opening ahead of the car park, a housing scheme releasing plots in phases. The contract divides the works into sections and gives each one its own completion date.
What follows from that is more than a scheduling convenience. Each section carries its own contractual consequences, and they arrive at different times.
What is separate
- Completion date. Each section has one, and each can be extended independently.
- Liquidated damages. Each section usually has its own rate, and damages accrue per section.
- Practical completion. Certified per section, on its own date.
- Rectification period. Runs from that section's practical completion, not from the last one.
- Retention. Released against that section, in the same two stages as any other contract.
Where the money gets stuck
Most commercial tracking, whether in a spreadsheet or in software, carries one practical completion date for the job. When the first section completes, the surveyor has three options: ignore it, adjust the whole retention manually, or halve everything. The first holds money that should have been released. The second creates a figure that cannot be reconciled to the certificate. The third releases money that is still security for the rest of the works.
None of those is a small error. On a scheme with an eighteen-month spread between the first and last sections, the money held incorrectly can run to six figures and sit there for a year.
Doing it properly
The mechanism is not complicated once the sections are given values. Retention accrues on the works as a whole at the contract rate. Each section then releases against its own value: half at its practical completion, the remainder at the end of its own rectification period.
That requires one discipline at the outset, which is apportioning the contract sum across the sections. It is worth doing carefully, because every retention release for the next two years is calculated from it. If the section values do not reconcile to the contract sum, the releases will eventually exceed or fall short of what was ever held, and nobody will notice until the last certificate.
Extensions do not apply evenly
A single delaying event can affect two sections by different amounts, or one section and not the other. A delay to a service diversion might push the section it serves by six weeks and leave the rest untouched.
This is why extension of time assessment on a sectional contract cannot be automated from a single register. The event is recorded once; the apportionment across sections is a judgement, and it needs to be written down with the reasoning, because it will be revisited.
Partial possession is not the same
Sectional completion is planned in the contract from the start. Partial possession is what happens when the employer wants part of the works early and the contract did not provide for it. The consequences look similar, but the route is different and so is the paperwork.
If phased handover is known at tender, put it in as sections. Retrofitting it through partial possession works, but it is a workaround, and it shows.
QScope holds each section separately, with its own value, dates and damages rate, and releases retention against that section at its own practical completion.