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London • South East • 18 years • 240+ builds

WE BUILD SPACE FOR YOUR LIFE. EXTENSIONS THAT WOW.

ExtensionPoint is a UK design + build studio for rear extensions, side returns, double-storey extensions, loft conversions and garden rooms. From first sketch to planning, building control and final polish — one fixed-price team.

Get free design consult →See 240+ projects
240+Extensions built
4.9★1,180 reviews
10yrInsurance guarantee
Modern rear house extension in London
🏗️
£45k – £180kTypical extension budget
Kitchen extension interior
8–14 weeksAverage on-site build
REAR EXTENSIONS ✦ SIDE RETURNS ✦ LOFT CONVERSIONS ✦ KITCHEN EXTENSIONS ✦ DOUBLE STOREY ✦ GARDEN ROOMS ✦ PLANNING + BUILD ✦ REAR EXTENSIONS ✦ SIDE RETURNS ✦ LOFT CONVERSIONS ✦ KITCHEN EXTENSIONS ✦ DOUBLE STOREY ✦ GARDEN ROOMS ✦ PLANNING + BUILD ✦ 
01 — Who we are / About Extension Point

Not just builders.
We are space-makers.

ExtensionPointCom started in 2007 as two brothers with a van in Camden. Today we are 42 architects, engineers, project managers and craftsmen obsessed with one thing: giving British families more light, more room, more home — without moving house.

18
years on site
Architectural plans for house extension
Builders working on extension

Design, planning & build under one roof — so you never chase trades again.

Most extension nightmares happen between architect, council and builder. We fixed that. Our in-house team draws, submits to planning, handles party wall, building regs, steel, drainage, electrics and joinery. You get one contract, one manager, one WhatsApp group and a fixed price.

✓
RIBA architects
3D visuals + full planning pack
✓
FMB & TrustMark
Vetted, insured, guaranteed
✓
Fixed price
No hidden extras, ever
✓
10-year warranty
Insurance-backed guarantee

“They turned our dark Victorian terrace into a glass-box kitchen we live in all day. On time, on budget, neighbours still love us.” — Sarah & Tom, Walthamstow, 6x4m rear extension

What we build →Meet us on site
02 — Services

Everything for your extension. End-to-end.

From permitted development to double-storey brick builds — pick a service or let us design the whole journey.

01
Single storey rear extension

Single-Storey Rear Extensions

3–6m glass, brick & render extensions. Open-plan kitchen-diners, skylights, bi-folds. From £48k.

Get quote →
02
Kitchen side return extension

Side Return & Kitchen

Victorian terrace side infills, structural steels, luxury kitchens, underfloor heating. From £55k.

Get quote →
03
Double storey extension

Double-Storey Extensions

Two floors, two bedrooms + kitchen below. Best £/m² value. Planning + party wall handled. From £95k.

Get quote →
04
Loft conversion

Loft Conversions

Dormer, L-shape, mansard lofts with ensuite. Stairs, fire regs, Velux. From £42k.

Get quote →
05
Garden room office

Garden Rooms & Annexes

Insulated offices, gyms, granny annexes. Foundations, electrics, plumbing in 3–4 weeks.

Get quote →
06
Planning and architectural design

Design, Planning & Regs

Measured survey, 3D design, planning application, building control, SAP & structural calcs.

Get quote →
03 — Selected work

Recent builds we're proud of.

Glass box extension Crouch End
Rear 5x4m • Crouch End

Glass-box kitchen diner

Steel portal, 4m sliders, polished concrete • 11 weeks • £68k

Side return extension Hackney
Side return • Hackney

Victorian dark to light

Side infill + rear, crittall doors, oak floor • 13 weeks • £82k

Double storey extension Bromley
Double storey • Bromley

2 beds + open plan

Brick match, ensuite, utility • 20 weeks • £138k

Luxury kitchen extension
Kitchen • Richmond

Chef's kitchen + pantry

Handleless units, island, rooflights • 9 weeks • £59k

Loft conversion Walthamstow
L-shape loft • Walthamstow

Master suite in the sky

Dormer + ensuite + dressing • 10 weeks • £54k

Garden room office
Garden room • Surrey

Office that feels like home

SIP build, heating, data cabling • 4 weeks • £32k

04 — How it works

From idea to keys in 5 steps.

01

Free survey + feasibility

We visit, laser-measure, check planning constraints and give honest budget in 48h.

02

Design + 3D visuals

2–3 concepts, walk-through renders, materials board. You tweak until you love it.

03

Planning + regs

We submit planning / permitted development, party wall notices, building control + steels.

04

Fixed-price build

Dedicated manager, weekly video updates, dust control, considerate neighbours policy.

98%On-time handover
£0Hidden extras
42In-house experts
10yrGuarantee
05 — Why Extension Point

Why London trusts us with their homes.

Finished extension exterior

💷 One fixed price, in writing

Detailed 12-page quote with every socket and tile. If we miss something, we pay — not you.

📱 You see everything live

Daily site photos, weekly video walk-around, live budget tracker and schedule in your client portal.

🌿 Warm, quiet, efficient

Triple-glazed, MVHR-ready, U-values beating regs by 20%. Lower bills from day one.

★★★★★

"No drama with planning or neighbours. The team handled party wall with both sides. Finished 4 days early!"

Client
Priya K.
Side return, Tooting
★★★★★

"The 3D design sold it. What we saw on screen is exactly what we got. Kitchen is now the heart of the house."

Client
James W.
Rear extension, Ealing
★★★★★

"Clean, polite, insanely organised. Our toddler napped through most of the build. Can't recommend enough."

Client
Emily R.
Double storey, Sutton
06 — Journal / News

Ideas, costs & planning tips.

Honest guides from our architects and site managers. Updated weekly.

Extension guide

How much does a house extension cost in the UK in 2026?

Full cost breakdown per m², hidden fees and how to save £15k without cutting quality.

Planning permission

Permitted development vs planning permission: 2026 rules

When you can build 6m without permission and when you really need full plans.

Kitchen design

12 kitchen extension layouts that actually work

Island vs peninsula, pantry walls, light tunnels — with real floor plans.

07 — FAQ

Questions? Answered.

Still unsure? Ask us anything →

Builders discussing plans
Do I need planning permission for an extension? +
Often not. Single-storey rear extensions up to 6m (semi/terrace 3–6m under prior approval) and many lofts fall under permitted development. We check your council, conservation area and previous extensions for free and handle the application if needed.
How much does an extension cost in London in 2026? +
Budget £2,800–£3,800 per m² for good quality, £3,800–£5,000 for high-end glass and bespoke joinery. A typical 20m² rear extension is £60k–£85k including VAT, steels, kitchen and fees. We give fixed quotes, not estimates.
How long will the build take? +
Single-storey: 10–14 weeks on site. Double-storey: 18–24 weeks. Loft: 8–12 weeks. Design + planning adds 8–12 weeks before that. We give you a week-by-week programme before you sign.
Do you handle party wall and building control? +
Yes. In-house surveyors serve notices, agree awards, and our structural engineers provide calcs + building regs drawings. You don't talk to the council — we do.
Can we live at home during the build? +
In 90% of cases, yes. We seal off dust, keep one toilet/kitchen live as long as possible, work 8am–4:30pm and lock up securely every night.

GET YOUR FREE
EXTENSION PLAN + QUOTE

Free 30-min survey • feasibility + budget in 48h • no pushy sales. Slots for next week in London, Essex, Surrey, Kent & Hertfordshire.

Book my free survey →or call 020 7946 0958

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📍
Studio & Showroom
124 Camden High Street, London NW1 0NE
Open Mon–Sat 9:00–17:30
📞
020 7946 0958
Mon–Fri 8:00–18:00 • Sat 9:00–14:00
✉️
hello @ extensionpointcom.co.uk
Drawings & quotes within 48 hours
Finished kitchen extension interior