Extension cost per m² in Cambridge
Extension cost by size in Cambridge
Each row multiplies the current £1,800–£3,000 per m² national benchmark by floor area and then applies the same regional factor.
What can change a real Cambridge quote?
- Floor area and number of storeys
- London and regional labour rates
- Steelwork and structural changes
- Kitchen or bathroom installation
- Glazing and door specification
- Finish level, access and contingency
Local planning considerations
Local labour demand, restricted central access and higher-specification property work can move real quotations outside the broad East of England planning range.
- Central access and delivery constraints can add logistics that are not captured by a simple regional multiplier.
- Check heritage, conservation or listed-building requirements before budgeting standard external alterations or replacement windows.
- Professional fees and specification choices can outweigh the regional factor on extensions, structural work and high-finish refurbishments.
How the regional model works
The 1.08× factor places this planning estimate 8% above the national planning baseline. We keep that modelling assumption separate from the dated national benchmark so users can see which part comes from an external source and which part is UK Home Costs modelling.
Sources
House Extension: Cost Breakdown 2026
Published / checked: June 2026
Used for: Extension cost-per-m² benchmarks and common add-on costs
Construction output price indices
Published / checked: 13 August 2026
Used for: Construction price trend and update checks
Frequently asked questions
How much does a house extension cost in Cambridge in 2026?
Our modelled Cambridge planning rate is about £1,950–£3,250 / m², based on the current national £1,800–£3,000 per m² benchmark and the East of England regional factor. This is not an observed city-wide quote average.
How much is a 20m² extension in Cambridge?
Applying the same regional model gives about £38,900–£64,800 before VAT for a straight-line 20m² example. Structural work, glazing, kitchens, bathrooms and access can move a real quote outside that range.
Why is the Cambridge estimate different from the UK benchmark?
UK Home Costs applies a 1.08× East of England planning factor, placing the model 8% above the national planning baseline. It is our modelling assumption rather than an external city price index.
Does the extension figure include VAT and professional fees?
The national benchmark is stated before VAT. Do not assume architect, structural engineer, planning, building-control, party-wall or specialist survey fees are included unless a contractor quote says so.