Kitchen Extension Cost in Muswell Hill: 2026 Price Guide

Ask a local builder what the most common job in Muswell Hill is, and a rear kitchen extension is usually near the top of the list - understandable given red-brick Edwardian parades along the Broadway and unified Edwardian and late Victorian houses on the residential streets radiating off it across much of the area. Most homeowners are chasing the same thing: a proper kitchen-diner instead of a cramped galley kitchen.

Typical costs

• Small extension (up to 15m²): roughly £30,000-£45,000
• Medium extension (15-25m²): roughly £45,000-£70,000
• Larger or wraparound extension (25m²+): £70,000 upwards

As with any ballpark figures, these cover the building work and a standard fit-out only - popular add-ons like bifold doors, roof lanterns and underfloor heating will move the total upward, sometimes significantly.

What affects the price locally

In Muswell Hill, the biggest local factor is usually access. Many streets are close terraces with no side access, which means materials have to be carried through the house and skips have to sit on the road - both of which builders will price in. Properties within the Muswell Hill conservation area - designated in 1974 and one of the largest in London - plus the Fortis Green and Rookfield Estate conservation areas sometimes face tighter controls on matching brick, roofline and window styles to the existing building, which can add to material costs even for a rear extension that doesn't need planning permission.

Foundations matter too - the Victorian and Edwardian housing near Alexandra Palace was typically built on shallower footings than current standards expect, so a structural engineer often specifies extra depth that a modern property simply wouldn't need.

Do you need planning permission?

Many single-storey rear extensions fall under permitted development, but there are limits on how far you can extend without full planning permission, and those limits are usually tighter for terraced and semi-detached houses than detached ones. If your home is in one of Muswell Hill's conservation areas, permitted development rights can be restricted further, so it's worth checking with the London Borough of Haringey's planning department - or a builder who works in the area regularly - before you commit to a design.