Extend or Move? Honest Cost Comparison 2026
Every homeowner who needs more space faces this decision. The financial case usually favours extending, but there are legitimate reasons to move. This guide compares both options honestly.
The details
The cost of moving (Dorset, 2026)
Moving from a £350,000 3-bed to a £450,000 4-bed costs: stamp duty (£12,500), agent fees (£5,250–£7,000), conveyancing (£2,000–£3,000), surveys (£500–£1,500), removals (£1,500–£3,000), plus the £100,000 price difference. Total cash outlay: £127,000–£142,000. And you start mortgage payments on a larger loan.
The cost of extending
Adding a bedroom + kitchen-diner via extension and/or loft conversion costs £65,000–£130,000 depending on scope. You keep your existing mortgage, neighbourhood, school, and neighbours. The work adds value to your current property.
When moving makes sense
Move if: you need to change area (schools, commute, lifestyle), your home cannot be meaningfully extended (tiny plot, structural limitations), the extension would cost more than the value it adds, or you want a fundamentally different type of home (flat to house, urban to rural).
| Factor | Extend | Move (£350k → £450k) |
|---|---|---|
| Cash outlay | £65,000–£130,000 | £127,000–£142,000 |
| Transaction costs | £0 | £27,000–£42,000 |
| Stamp duty | £0 | £12,500 |
| Disruption | 10–20 weeks | 3–6 months |
| School change | No | Possibly |
| Mortgage impact | Possible remortgage | New larger mortgage |
| Value added | 5–15% of current value | N/A |
Our verdict
Extending is almost always cheaper when you factor in the full cost of moving — especially stamp duty and agent fees. Move only if you need a different location, a fundamentally different property type, or your home cannot accommodate the space you need.
Common questions
Frequently asked questions
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