Home Extension FAQs: Answers Every Surrey Homeowner Should Know Before Building

Home Extension FAQs: Answers Every Surrey Homeowner Should Know Before Building

If you're planning a home extension in Farnham, searching for a builder in Guildford, or comparing options across Surrey, you probably have one thing in common:

Questions. Lots of them.

That’s normal. Extending your home is a major investment, and getting the right answers early can save thousands of pounds, months of stress, and costly mistakes later.

At Forsyth Construction Surrey Ltd, we believe informed clients make better decisions. So here are the most common extension questions we hear from homeowners.

1. How much does a home extension cost in Surrey?

This depends on size, complexity, specification, and structural requirements.

Typical guide prices:

• Single-storey extension: £2,200–£3,200 per m²

• Rear kitchen extension: £45,000–£95,000+

• Double-storey extension: £75,000–£160,000+

• High-end bespoke extension: £180,000+

  
  

Be cautious of quotes dramatically cheaper than others.

Often, something is missing.

2. Do I need planning permission?

Not always.

Many extensions fall under Permitted Development, but it depends on:

• Property type

• Previous extensions

• Size proposed

• Conservation areas

• Boundary distances

• Roof height and design

For homeowners in Farnham and Guildford especially, local planning context matters.

Always verify before committing.

3. How long does an extension take?

Typical build times:

• Small rear extension: 10–14 weeks

• Medium extension: 14–20 weeks

• Large / structural projects: 20+ weeks

This excludes design, approvals, engineering and lead times.

A realistic programme matters more than an unrealistic promise.

4. Can we live in the house during the build?

Usually yes — but it depends on:

• Kitchen relocation needs

• Structural openings

• Dust/noise tolerance

• Young children or pets

• Temporary services disruption

  
  

Many clients remain in place for part or all of the project.

We always advise honestly based on the specific scheme.

5. What adds the most value?

Popular high-return extensions include:

• Open-plan kitchen / dining spaces

• Rear family extensions

• Loft conversions

• Utility + boot room additions

• Extra bedrooms with en-suites

  
  

The best value often comes from improving how you live, not just adding square metres.

6. How do I compare builder quotes properly?

This is where many homeowners go wrong.

Don’t compare only the final price.

Check for:

• Full specification detail

• Structural steel allowances

• Electrics included?

• Plumbing included?

• Decoration included?

• Waste removal included?

• Kitchen / flooring exclusions

• Provisional sums

• Project management responsibility

  
  

If one quote is dramatically cheaper, something is often omitted.

7. What causes budget overruns?

Most overruns come from:

• Incomplete quotations

• Late design changes

• Hidden structural issues

• Cheap initial pricing

• Poor planning

• Low-quality management

  
  

Transparent pricing at the start reduces surprises later.

8. Should I move house instead of extend?

Often, extending can be smarter than moving once you factor in:

• Stamp duty

• Legal fees

• Agent fees

• Moving costs

• Higher mortgage rates

• Losing a location you love

  
  

For many Surrey families, extending is the better long-term move.

9. When should I speak to a builder?

Earlier than most people think.

The best time is:

• After initial ideas

• Before submitting final drawings

• Before tendering blindly

• Before setting unrealistic budgets

  
  

Early contractor input can save major redesign costs.

10. How do I choose the right builder in Farnham or Guildford?

Look for:

• Proven local projects

• Clear communication

• Detailed quotations

• Strong reviews

• Realistic timelines

• Professional process

• Quality finish examples

  
  

Choose value, not just price.

Why Homeowners Choose Forsyth Construction Surrey Ltd

We specialise in:

• Home extensions

• Structural alterations

• Renovations

• Refurbishments

• High-quality domestic building projects

  
  

Clients value our:

✔ Transparent pricing✔ Honest advice✔ Professional management✔ Reliable timelines

✔ Excellent finish quality

Planning an Extension in Farnham, Guildford or Alton?

If you’d like practical advice before committing to drawings or quotes, we’re happy to help.

Contact Forsyth Construction Surrey Ltd today to discuss your project.