How Much Does a House Extension Cost in Godstone and Tandridge? (2026 Guide)
Planning an extension in Godstone, Oxted or elsewhere in Tandridge? Realistic 2026 cost bands (£2,500–£3,500/m²), what pushes prices up or down locally, and how green belt affects what you can build.
If you own a home in Godstone, Bletchingley or anywhere in the Tandridge district and you're weighing up an extension, the first two questions are always the same: what will it cost, and will the green belt let me do it? This guide answers both with realistic 2026 numbers.
The honest cost bands for Tandridge in 2026
For a typical single-storey rear or side extension around Godstone, sensible budgeting starts at:
- £2,500–£3,000/m² — solid standard specification: bricked to match, standard bi-folds, plastered and decorated, allowances for kitchen contribution rather than a full high-end kitchen.
- £3,000–£3,500/m² — higher specification: structural glazing, larger spans with steels, underfloor heating, premium finishes.
So a common 3m x 7m (21m²) rear extension lands roughly between £52,000 and £74,000 including VAT, before professional fees. Those fees — architectural drawings, structural calculations and approvals — typically add 10–12% of build cost, and we always recommend holding a 10% contingency on top.
We've written before about why builder estimates vary so much — the short version is that two builders quoting "the same" extension are rarely pricing the same specification. A full specification of works is what makes quotes comparable.
The green belt question
Tandridge is one of the most constrained districts in England — roughly 94% of the district is green belt. Homeowners often assume that kills any extension plan. It usually doesn't:
- Permitted development rights still apply to most houses in the green belt. Single-storey rear extensions up to 4m (detached) or 3m (other houses) — and up to 8m/6m under the larger-home scheme with prior approval — often need no full planning application.
- Where planning permission is needed, Tandridge District Council's tests centre on whether the extension is proportionate to the original dwelling. Well-designed side and rear additions are routinely approved.
- What the green belt genuinely restricts: disproportionate additions that dwarf the original house, and outbuildings that amount to a separate dwelling.
If your house is in the Godstone conservation area or is listed, an extra layer applies — worth a conversation before you commit to a design.
What moves the price locally
A few Tandridge-specific factors we see again and again:
- Sloped plots. Homes off Godstone Hill or on the North Downs fringe often need stepped foundations and careful drainage — flat-site cost estimates miss this.
- Access. Narrow rural lanes and shared drives affect skip placement, deliveries and programme.
- Matching materials. Older stock around the village green may warrant reclaimed brick or clay tiles to satisfy both planning and resale value.
Getting from "roughly" to "actually"
Cost-per-square-metre gets you a budget envelope; a design and a specification get you a real number. Our design-and-build approach means the same team that draws your extension prices it and builds it — no gap between what was drawn and what was quoted.
If you're in Godstone or the surrounding villages, we offer a free consultation to walk your project, talk through planning honestly, and give you a realistic budget before you spend anything on drawings. Book a call — or read more about our home extension service.