Extension vs moving house: which is better for your family?

Updated June 2026 9 min read

Quick verdict

Extending is usually cheaper than moving if you like your location and the house can take the extra space. Moving is better when you need a different area, schools, plot size or layout that an extension cannot fix.

Option A

Extension

Building extra living space onto your existing property, such as a rear, side return, wraparound, single-storey or double-storey extension.

Option B

Moving house

Selling your current home and buying another property to gain more space, a different layout or a better location.

Side-by-side comparison

A home extension normally wins on cost once estate agent fees, legal fees, removals and stamp duty are included. Moving wins when location, schools, parking or overall layout matter more than adding floor space.

Typical cost for more space

Extension

About £40,000 to £80,000 for 20m2Better

Moving house

Often £80,000 to £150,000+ extra after price gap and moving costs

Stamp duty

Extension

NoneBetter

Moving house

May be significant

Disruption

Extension

Building work for 2 to 4 months

Moving house

Sale, purchase and move process

Change location

Extension

Moving house

YesBetter

Planning

Extension

Permitted development or planning may apply

Moving house

Not applicableBetter

Potential value return

Extension

Often strong if well designedBetter

Moving house

Depends on market and purchase price

Best for

Extension

You like the area and need space

Moving house

You need a different area or property type

Compare	Extension	Moving house
Typical cost for more space	About £40,000 to £80,000 for 20m2Better	Often £80,000 to £150,000+ extra after price gap and moving costs
Stamp duty	NoneBetter	May be significant
Disruption	Building work for 2 to 4 months	Sale, purchase and move process
Change location	No	YesBetter
Planning	Permitted development or planning may apply	Not applicableBetter
Potential value return	Often strong if well designedBetter	Depends on market and purchase price
Best for	You like the area and need space	You need a different area or property type

Pros and cons

Extension pros and cons

Pros

✓Usually cheaper than upsizing
✓No stamp duty
✓Stay near schools and neighbours
✓Adds tailored living space
✓Can increase property value

Cons

-Building disruption
-May need planning approval
-Risk of budget overruns
-May reduce garden space
-Not every house is suitable

Moving house pros and cons

Pros

✓Change location
✓Choose a better layout
✓Avoid building work
✓Can gain garden, parking or school catchment
✓Immediate finished result after completion

Cons

-Stamp duty and transaction costs
-Estate agent and legal fees
-Chain risk
-Higher mortgage may be needed
-Emotional and practical upheaval

Cost examples

Family in the right area

A rear extension can add kitchen-dining space without changing schools or commute.

Likely fit: Extension

Wrong location

If the issue is schools, transport or parking, moving may solve more than extra floor space.

Likely fit: Moving

Tight plot

If an extension would remove too much garden, moving can be more practical.

Check: Plot

When to choose Extension

›You like your current area
›You need one or two extra rooms
›You have enough garden or side space
›You want to avoid stamp duty
›You can tolerate building work

When to choose Moving house

›You need a different school catchment
›You want a larger garden or driveway
›Your current layout cannot be fixed
›Planning would be difficult
›You do not want months of building disruption

FAQs

Is it cheaper to extend or move house?

Extending is often cheaper once stamp duty, agent fees, legal fees and removals are included, but it depends on build cost and local house prices.

Does an extension add value?

A well-designed extension can add value, especially if it creates a larger kitchen, extra bedroom or better living layout.

Do I need planning permission for an extension?

Some extensions fall under permitted development, but limits apply. Larger or sensitive projects may need planning permission.

When is moving better?

Moving is usually better when the real problem is location, schools, parking, plot size or a layout that cannot be improved enough.

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