House Extension Cost in Folkestone — 2026 Prices
A typical house extension in Folkestone runs £42,000–£120,000 all-in based on quotes we've written over the past two years across the CT19, CT20 postcodes. The mid-range — roughly £48,300–£102,000 — is where most Folkestone projects land once spec, finish level and structural complexity settle.
Get a Folkestone quote
Free site visit. Itemised written quote in 5 working days.
What drives house extension cost in Folkestone
Folkestone's typical housing stock — Victorian seafront terraces, Creative Quarter conversions, new-build estates — has a big effect on cost. Conservation overlays around Folkestone Creative Quarter can push joinery and roofing spec up by 10–15% because of matching tile, lime mortar or sash detailing.
- • Structural complexity (RSJs, foundations, knock-throughs)
- • Conservation / Article 4 detailing on listed or near-listed stock
- • Spec of kitchen, bathroom, joinery and flooring
- • Access — terrace, narrow lane, off-street parking
- • Whether you stay on site or move out
Itemised cost breakdown
Every Folkestone house extension quote we send breaks down into these lines so you can compare like-for-like with other builders.
- • Site set-up, scaffold, skip, welfare — £1,680–£6,000
- • Structural & foundations — £7,560–£26,400
- • Shell, roofing, glazing — £9,240–£31,200
- • M&E (plumbing, electrics, heating) — £5,040–£18,000
- • Joinery, kitchen / bathroom, finishes — £11,760–£38,400
- • Contingency (10%) — held back, not spent unless needed
In short
Most house extension projects in Folkestone land between £48,300–£102,000 all-in. The fastest way to get a real number for your CT19, CT20 address is a 30-minute site visit followed by an itemised written quote.
Folkestone cost FAQs
Is Folkestone more expensive than other parts of Kent for a house extension?
Marginally — Folkestone's CT19, CT20 postcode runs about 3–6% above the Kent average, mostly because of conservation detail and parking constraints near The Leas. The biggest cost variance is still spec, not postcode.
Will you provide a fixed-price quote or estimate?
Fixed-price written quote — itemised across the lines above, with a 10% contingency you only pay if it's actually used. We've worked on The Leas and surrounding Folkestone streets so we price from real local knowledge, not desktop assumptions.
What's the deposit and payment schedule?
10% on contract signing, then stage payments tied to milestones (slab down, weathertight, first fix, second fix, completion). Final 5% retained for 4 weeks post-handover.
Do you include VAT in quotes?
Yes — every Folkestone quote is VAT-inclusive. We're VAT-registered. Some listed-building work in Folkestone qualifies for reduced-rate VAT; we'll flag this if applicable.