Extensions
Single storey, double storey and wrap-around
An extension covers design, structural calculations, groundworks, shell, roof, glazing, first and second fix and finishes. Cost is driven by floor area, glazing and ground conditions.
AVERAGE UK PRICE
£2,200 per m²
Typical range £30,000 – £120,000
Typical timeline12–24 weeks
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Benefits
- Often adds more value than it costs in high-demand areas
- Avoids the cost and stress of moving house
- Opportunity to upgrade insulation and heating at the same time
Common problems
- Drainage runs needing diversion
- Party wall agreements with neighbours
- Poor ground conditions requiring deeper foundations
Before and after
Recent extensions projects completed through PlanMyBuild.
Before
After
Before
After
Frequently asked questions
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