Builder Costs in Barnet
London | Prices updated for 2026 | All estimates include labour and materials
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Estimated cost in Barnet
£18,480 - £50,160
Single Storey Extension (medium (15-25 sqm))
Typical duration: 6-12 weeks
Builder Prices in Barnet
Single Storey Extension
£18,480 - £50,160Labour
£10,560 - £26,400
Materials
£7,920 - £23,760
Typical duration: 6-12 weeks
Garage Conversion
£8,580 - £19,800Labour
£5,280 - £11,880
Materials
£3,300 - £7,920
Typical duration: 2-4 weeks
Internal Wall Removal
£924 - £3,036Labour
£660 - £1,980
Materials
£264 - £1,056
Typical duration: 1-3 days
Patio Construction
£1,716 - £5,940Labour
£1,056 - £3,300
Materials
£660 - £2,640
Typical duration: 2-5 days
How Barnet Compares
More expensive
Trade prices in Barnet are typically 32% above the national average. This reflects local labour rates and the cost of living in London.
Seasonal Demand for Builder Work
Peak demand is typically in Jul, with the quietest period around Jan. You may find lower prices and better availability during off-peak months.
What Affects the Price
Single Storey Extension
- Extension size (square metres)
- Foundation type required by ground conditions
- Roof design (flat, pitched, or lean-to)
- Level of internal finish and specification
- Planning permission or permitted development status
Garage Conversion
- Garage size and structural condition
- Level of insulation and damp proofing needed
- Whether plumbing or electrics are required
- Quality of internal finish
Internal Wall Removal
- Whether the wall is load-bearing
- Steel beam size and specification
- Services (pipes, wires) running through the wall
- Making good to floor, ceiling, and adjacent walls
Patio Construction
- Patio area (square metres)
- Material choice (concrete slabs, natural stone, porcelain)
- Ground preparation and levelling
- Drainage and edging requirements
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Frequently Asked Questions
How much does a builder cost in Barnet?
Builder prices in Barnet typically range from £924 for internal wall removal to £50,160 for single storey extension. Prices include both labour and materials.
What is the average cost of single storey extension in Barnet?
Single Storey Extension in Barnet costs between £18,480 and £50,160 on average, depending on the scope of work and materials chosen.
When is the cheapest time to hire a builder in Barnet?
Demand for builder work in Barnet is typically lowest in January. Booking during quieter months may mean better availability and competitive pricing.
Are builder prices in Barnet above or below the national average?
Builder prices in Barnet are around 32% above the national average, reflecting higher local labour rates and cost of living.
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