House Extension Cost in Marden — 2026 Prices
A typical house extension in Marden runs £42,000–£120,000 all-in based on quotes we've written over the past two years across the TN12 postcodes. The mid-range — roughly £48,300–£102,000 — is where most Marden projects land once spec, finish level and structural complexity settle.
Our Biddenden yard is 7 miles (~16-minute drive) from Marden, so we don't carry distance loadings into Marden quotes the way a London or coast-based contractor would. That alone is usually 8–12% off the headline number.
Below is the cost breakdown we use in every written Marden quote — labour, materials, structural, finishes and a contingency line. No "from £X" headline pricing.
What drives house extension cost in Marden
Marden's typical housing stock — Victorian station terraces, 1960s estates, oast conversions — has a big effect on cost. Conservation overlays around Marden Village Centre 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 Marden 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
Get a real house extension price for your Marden property
Free site visit, written itemised quote within 5 working days. No "from" pricing — actual numbers for your address.
Marden cost FAQs
Is Marden more expensive than other parts of Kent for a house extension?
Marginally — Marden's TN12 postcode runs about 3–6% above the Kent average, mostly because of conservation detail and parking constraints near St Michael's Church. 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 West End and surrounding Marden 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 Marden quote is VAT-inclusive. We're VAT-registered. Some listed-building work in Marden qualifies for reduced-rate VAT; we'll flag this if applicable.
Related guides
Nearby areas we also cover
In short
Most house extension projects in Marden land between £48,300–£102,000 all-in. The fastest way to get a real number for your TN12 address is a 30-minute site visit followed by an itemised written quote.