Sequencing a new-build programme from groundworks to first fix
A new build's critical path runs in a genuinely different order to a renovation's. There's no strip-out, no working around an occupied structure — but a great deal more has to happen below ground before anything above it can start.
It's tempting to think of a new-build programme as simpler than a renovation's, because there's no existing structure to work around or protect. In one sense that's true. In another, it's the opposite: a new build has to establish everything from nothing, in a specific order, and the stages that look straightforward on a bar chart are frequently where the real risk sits.
The critical path starts before the site is cleared
Services connection applications, ecology surveys that can only be done in the right season, and a warranty provider's pre-commencement requirements all sit on the critical path before groundworks begin — and each has its own lead time, measured in weeks to months rather than days. A programme that only starts counting from the first digger on site has already lost the time these steps actually took.
Groundworks: the widest range of outcomes in the whole programme
As with budget, groundworks is the programme stage most likely to reveal something — made ground, an unexpectedly high water table, a services clash — that changes the sequence of everything downstream. Building float in specifically here pays for itself more reliably than float placed anywhere else in the programme, precisely because it's the stage with the least visibility before you start.
Substructure to superstructure: the warranty inspection gate
Each early stage — foundations, damp-proof course, oversite — typically needs the warranty inspector's sign-off before it's covered up. Booking these inspections with proper notice, and genuinely not covering the work before sign-off, protects both the warranty and the mortgage drawdown that depends on it. It's a discipline worth building into the programme deliberately, not a bureaucratic delay to route around when the contractor's ready to move on.
Weathertight is the milestone that changes everything
Once a building is watertight — roof on, windows and external doors in — internal trades can proceed largely regardless of weather. A programme that gets a structure watertight before winter, versus one that's still open to the elements into December, has a materially different internal fit-out programme even with identical labour and identical weather afterwards. Where the weathertight milestone lands relative to the season is worth planning for deliberately, not discovering by accident.
First fix and the trades that can't overlap
First fix electrics, plumbing and structural carpentry can broadly run in parallel with coordination, but each depends on the building fabric being complete enough that chasing, drilling and routing won't need redoing later. A common self-build delay is first fix trades arriving before the building is genuinely ready for them, which creates abortive work and a dispute about whose fault the delay was — usually avoidable with a clearer definition of 'ready' in the programme itself.
Where self-build programmes typically lose the most time
- Long-lead items — windows, structural timber frame, bespoke joinery — ordered late rather than at design sign-off
- Warranty and building control inspection booking lead times underestimated
- Weather risk on groundworks and roof stages not allowed for at all
- Services connections applied for only once the build is already underway
- No float held specifically against the groundworks stage, where the widest range of outcomes actually sits