Cheam, London
Areas · Sutton · South London
Cheam · SM1 · SM2 · SM3

House extensions in Cheam

Cheam sits in Sutton, where the streets are dominated by long Victorian terraces with narrow side returns and original rear closet wings. The build that pays back most reliably here is a double-storey rear that adds a bedroom and en-suite above the new kitchen.

Typical all-in (inc VAT)
£84k–£134k
Build rate per m²
£2675–£4075
On-site programme
12–20 weeks

What we build in Cheam

Most Cheam projects we scope fall into three buckets: a side-return or rear infill that fixes a dark galley kitchen, a full-width rear extension that opens the ground floor to the garden, and a rear-plus-loft package that adds a bedroom while the scaffold is already up. 1930s semis and detached, some Arts & Crafts in Cheam.

Rear extensionWraparoundLoft

Extension costs in Cheam

A mid-spec 25 m² extension in Cheam typically lands between £84,000 and £134,000 all-in — that figure includes professional fees, planning and Building Control, party wall, a 12% contingency and VAT at 20%. Ex-VAT build rates run £2675–£4075 per m² depending on glazing, structural spans and kitchen spend.

ProjectSizeCheam all-in
Side return infill15–20 m²£63k – £101k
Full-width rear20–30 m²£84k – £134k
Wraparound30–45 m²£122k – £194k
Double-storey rear40–60 m²£164k – £261k

Planning permission in Cheam

Sutton is broadly PD-friendly. Cheam Village and Beddington Park conservation areas need more design attention.

Before you assume permitted development applies to your street, check whether your street falls inside a conservation area or an Article 4 direction — both are common in Sutton and both remove PD rights for rear and side extensions. Our London planning guide walks through the tests in order.

Party wall and neighbours

Semi-detached typology.

Serve notice at least two months before you break ground. Budget £1,200–£2,400 per adjoining owner if they dissent and appoint their own surveyor — see the Party Wall Act guide.

Access, logistics and site set-up

Tight on-street parking means bay suspensions and timed deliveries — your builder should price this, not absorb it.

Every quote we issue for Cheam prices skip permits, parking suspensions, protection and welfare explicitly in the preliminaries — so the number you sign is the number you pay.

Value added in Cheam

Buyers in this area consistently pay a premium for open-plan kitchen-diners with direct garden access.

Typical programme

  1. Weeks 0–4Measured survey, design and structural calcs
  2. Weeks 4–12Planning or lawful development certificate, party wall notices
  3. Weeks 12–16Tender, builder selection and contract signing
  4. Weeks 16–34On site: groundworks, shell, watertight, first and second fix
  5. Week 35Building Control sign-off, snagging and handover

Full detail in the London extension timeline guide.

Why homeowners in Cheam use us

  • KYB-verified builders only
  • Live Sutton project experience
  • Itemised fixed-price specifications
  • Insurance, warranty and accreditation checks
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