How Long Does a House extension Take in Sevenoaks?
A house extension in Sevenoaks typically takes 12–22 weeks on site once we start. That's the build phase only — design, planning approval, building regs and material lead-times add roughly 12–20 weeks before a spade goes in.
Sevenoaks projects in TN13, TN14, TN15 occasionally run longer when conservation officer comments come back on materials. We build that into our programme up front rather than discovering it mid-job.
Week-by-week programme for Sevenoaks
This is the standard Gantt we issue with every Sevenoaks house extension contract. You'll see each week's milestones in writing so progress is unambiguous.
- • Weeks 1–2: Strip out, set up, structural opening up
- • Weeks 3–6: Foundations / shell / structural
- • Weeks 7–17: First fix M&E, glazing, weathertight
- • Weeks 18–21: Second fix, joinery, plastering, tiling
- • Final week: Snagging, building control sign-off, handover
What slows a Sevenoaks project down
Sevenoaks's conservation requirements and the lead-time on heritage materials (peg tiles, oak, lime mortar) are the two biggest sources of delay we see. We pre-order long-lead items before we start on site to keep the programme.
- • Conservation officer requesting material samples (add 1–2 weeks)
- • Bespoke joinery lead-times — typically 4–6 weeks from sign-off
- • Engineer revisions if structural assumptions change once opened up
- • Client decision delays on finishes (we set a "lock-by" date per stage)
Get a written Sevenoaks programme with your quote
Every Sevenoaks project starts with a Gantt chart, lock-by dates for each stage, and a programme review every Friday on site.
Programme questions we get from Sevenoaks
Can a house extension in Sevenoaks be done faster than 12 weeks?
Occasionally — small straight refits with no structural change can run shorter, but we don't quote unrealistic programmes to win work. A 12-week minimum is what we deliver to.
Do you work on site every day in Sevenoaks?
Monday to Friday 7am–5pm, Saturday morning when programme needs it. Sevenoaks's residential conservation areas have noise restrictions we comply with.
What happens if you run over the programme?
Contract has liquidated damages clauses on programme slip caused by us. Weather and client variation changes are flagged in writing as they happen so the programme stays accurate.
Can we live in the house during a house extension in Sevenoaks?
For loft conversions and most kitchen / bathroom refits — yes, with one room out of action at a time. For full house extensions opening up the back of the property, moving out for 4–6 weeks is usually easier.
Related guides
Nearby areas we also cover
In short
12–22 weeks on site for a house extension in Sevenoaks, plus design and planning lead-time. Every project gets a written week-by-week programme up front.