Hillingdon, London
Boroughs · West London
Hillingdon · Outer London

House extensions in Hillingdon

Hillingdon combines the biggest plots in outer west London with London's most permissive planning stance — ideal for ambitious wraparounds on tight budgets.

Typical all-in (inc VAT)
£85k–£140k
Cost vs London base
-5%
Postcodes covered
UB3 · UB4 · UB7 · UB8

Housing stock in Hillingdon

1930s semis and detached, larger Arts & Crafts in Ruislip and Northwood.

WraparoundRear extensionDouble-storey

Planning in Hillingdon

One of the most PD-friendly boroughs in London. Northwood and Ruislip Manor conservation areas are the exceptions.

Party Wall Act — what to expect

Semi-detached — one party wall typical, often none for detached homes.

Read the Party Wall etc. Act 1996 guide for full detail on notices, timelines and surveyor costs.

Typical costs in Hillingdon

For a mid-spec 25 m² kitchen extension, all-in (professional fees, planning, party wall, VAT and 12% contingency), expect roughly £85,000 to £140,000. High-spec finishes, structural glazing or a full basement dig-out will push above the top of this range; a smaller side-return can come in under the bottom.

Cost tier
Outer London · -5% vs London average

Our calculator applies a 0.95× multiplier automatically for Hillingdon projects. Get an itemised breakdown in 60 seconds.

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Areas we cover in Hillingdon

UB3UB4UB7UB8UB9UB10HA4HA6

Why homeowners in Hillingdon pick us

  • KYB-verified builders only
  • Local Hillingdon project experience
  • Fixed, itemised written quotes
  • Full insurance & warranty checks
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