🏡 How Much Does a Home Extension Cost in Surrey in 2026?

As builders working in Ashford, Surrey one of the first questions homeowners ask us is:

“How much should I budget for my extension?”

This guide breaks down the numbers clearly, so you can plan with confidence before speaking to a builder or architect.

🔍 So, what does an extension cost in Ashford, Surrey in 2026?

In 2026, most extensions in Ashford, Surrey fall into £2,500 - £3,500 per m² for construction only.

This doesn’t include design, planning, kitchens, bathrooms or landscaping, we’ll break those down below.

The final cost depends on:

• Size
• Specification
• Structural complexity
• Ground conditions
• Finishes (standard vs luxury)

📌 Average Build Costs (2026)

Single-storey extension

£2,500 – £3,000 per m²
(typical Ashford, Surrey range for high-quality builds)

What affects the price?

• Flat roof vs pitched
• Bi-folds/slider cost
• Steel work
• Insulation
• Finish level (standard plaster & paint vs full kitchen install)

Double-storey extension

£2,800 – £3,500 per m²

Why more expensive?

• Additional structural work
• More scaffolding
• First-floor bathrooms/bedrooms
• More Electrics & Plumbing
• Higher insulation and fire protection requirements

💷 Realistic Total Project Budgets (2026)

Here’s what most Ashford, Surrey homeowners actually spend when all elements are included:

Small extension (10–15m²)
£35,000 – £55,000+
Medium extension (20–30m²)
£60,000 – £95,000+
Large wrap-around or major reconfiguration (35–55m²)
£110,000 – £175,000+
Double-storey extensions
£120,000 – £220,000+

These are realistic Surrey prices for projects finished to the standard we deliver at IN Construction Ltd; clean, modern, high-spec, high-detail work.

🛠 Additional Costs to Factor In

• Architectural drawings & structural engineering
  Basic drawings: £1,200 – £2,500+
  Full planning set + construction pack: £2,500 – £5,500+
  Structural engineer: £450 – £1,500+
  Planning permission & approvals
  Planning fee: £258-£528
  Building control: £600 – £1,200+
• Kitchens & bathrooms
  These vary hugely based on finish:
  Kitchens: £7,000 – £35,000+
  Bathrooms: £4,000 – £12,000+
• Windows, Bi-fold Doors, Sliding Doors & Roof-lights
  Sliding Doors: £3,000 – £8,000+
  Bi-fold Doors- £4,000 - £10,000+
  Roof-lights: £800 – £2,000+
  Lanterns: £1,500 – £3,500+
• Heating, electrical & plumbing upgrades
  Rewires, UFH, boilers, consumer unit upgrades: £1,500 – £8,000+
• Flooring & finishing
  LVT/herringbone: £50–£150 per m²
• Tiling £70–£150 per m²
• Painting/decorating: £1,500 – £5,000+

🧱 Why Ashford, Surrey Extensions Cost More Than the UK Average

Surrey typically sits at the higher end of UK construction pricing due to:

• Higher labour rates
• Higher material costs
• More complex house types (older stock, restricted access, narrow plots)
• Homeowners opting for higher-end finishes
• Strict local building control and insulation requirements

👷‍♂️ How IN Construction Ltd Helps You Avoid Unexpected Costs

Working in Ashford, Surrey we specialise in:

• Transparent, detailed estimates/quotations
• Clear payment schedules
• Strong communication
• Phased/value-engineered options
• Helping clients make informed decisions before committing
• This is exactly why homeowners trust us, and why our projects run smoothly.

📸 Example: What Drives Costs Up or Down

• Cheaper options
• Standard UPVC windows
• Flat roof with single roof-light
• No major internal reconfiguration
• Standard plaster & paint
• Simple electrics
• More expensive options
• Aluminium sliders
• Roof lanterns or multiple roof-lights
• Full structural knock-throughs
• Underfloor heating
• High-end kitchens
• Herringbone flooring
• Bespoke carpentry

🔮 Will Extension Prices Drop Later in 2026?

Short answer: unlikely.

Material prices have stabilised but aren’t dropping dramatically, and skilled labour in Surrey remains in high demand. Homeowners planning extensions this year shouldn’t expect lower prices by waiting.

📞 Thinking About Extending Your Home?

If you’re planning an extension in Ashford, Surrey we’re always happy to offer guidance.

👉 Request a free initial consultation today

📱 07748 993 763

📞 01784 542265

📧 info@inconstructionltd.co.uk

🔗 @inconstructionltd