Post a job free and get contacted by local experienced builders in Barnet within hours. Covering EN4, EN5, N20, N11, N12 postcodes.
Single and double storey extensions for Barnet's large 1930s and post-war detached homes. Generous plots across EN4, EN5, and N20 make rear and side extensions very feasible.
Find a builder →Velux, dormer, and hip-to-gable loft conversions across Barnet. The leafy borough's detached housing stock is ideal for adding a full floor of additional space.
Find a builder →Full house refurbishments and upgrades across Barnet — high EPC improvement demand, kitchen and bathroom refits, and internal remodelling.
Find a builder →Office refurbishments and commercial building works across Barnet, East Barnet, New Barnet, and the surrounding EN and N postcode areas.
Find a builder →RSJ steel beam installation, load-bearing wall removal, and structural alterations for Barnet's detached and semi-detached properties.
Find a builder →Garden rooms, annexes, and garage conversions are extremely popular in Barnet's larger plots. New build single dwellings on infill plots also common.
Find a builder →| Job | Low estimate | High estimate |
|---|---|---|
| Single-storey rear extension | £25,000 | £50,000 |
| Double-storey extension | £45,000 | £90,000 |
| Loft conversion (Velux) | £20,000 | £35,000 |
| Loft conversion (dormer) | £35,000 | £65,000 |
| Full house refurbishment (3-bed) | £40,000 | £100,000 |
| Kitchen extension (open plan) | £30,000 | £60,000 |
| Garage conversion | £12,000 | £25,000 |
| Garden room / studio | £15,000 | £40,000 |
| Basement conversion | £40,000 | £80,000 |
| Party wall agreement | £700 | £2,000 |
| Load-bearing wall removal (RSJ) | £1,500 | £4,000 |
| New build (per m²) | £2,000 | £4,000 |
Prices are estimates for Barnet 2026. Always get at least three quotes before committing to any work.
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Barnet is one of North London's leafiest and most desirable outer boroughs, covering the EN4, EN5, N20, N11, and N12 postcode areas. The dominant housing stock is large 1930s and post-war detached and semi-detached homes with generous plot sizes — conditions that are ideal for a wide range of building projects. Unlike many inner London boroughs, Barnet has relatively few conservation area restrictions across its residential streets, meaning Permitted Development rights apply to most properties and standard extensions can proceed without full planning applications. This makes Barnet one of the more builder-friendly outer London boroughs for residential projects.
Garden rooms, annexes, and garage conversions are growing strongly in Barnet, driven by the borough's large plots and the shift to home working. Loft conversions are equally popular — Barnet's characteristic 1930s hip-roofed semis are perfectly suited to hip-to-gable plus rear dormer conversions that add a full extra bedroom and bathroom. The affluent character of areas like New Barnet, Cockfosters (EN4), and Whetstone (N20) supports a high-specification refurbishment market, and EPC improvement work is also increasingly in demand as homeowners prepare properties for stricter energy efficiency standards.
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Covering EN4 · EN5 · N20 · N11 · N12 · N3 · NW4