Expert Designers
for Home
Extensions
Hassle free, from the first sketch to the final handover — no gaps, no surprises.
Meet your designer
“Good design isn't just about how a space looks — it's about how it makes you feel the moment you walk in.”
- 🏠Residential interiors & extensions
- ✏️Space planning & concept design
- 🪵Materials, finishes & specification
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Drawings Complete
Architectural and technical drawings delivered across all sectors
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Average Project Value
We work on projects from £10,000 all the way up to £5 million
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Design Hours Complete
Hours invested in design, coordination and delivery
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Years of Combined Experience
Extensions · Loft conversions · Interior design · New builds
Our featured work
Case Studies
From rear extensions to full loft conversions — a selection of recently completed projects.
What We Do
Specialists in residential
design & delivery
All services 01
Home Extensions
More space, without moving
Rear and side extensions designed around how you actually live. We handle permitted development, planning permission, structural coordination, and party wall matters — so you don't have to.
- Feasibility & planning permission
- Permitted development advice
- Structural engineer coordination
- Party wall matters & building regs
02
Loft Conversions
Unlock your roof space
We assess structural feasibility, design the dormer and staircase, manage building regulations and oversee the build from first consultation to signed-off completion.
- Structural feasibility & permitted development
- Dormer, mansard & hip-to-gable design
- Staircase integration
- Building regulations & sign-off
03
Interior Design
Spaces that feel like home
From space planning to material selection, lighting and bespoke joinery — we create interiors where every finish, fitting and detail is considered so the result feels effortless.
- Space planning & layout optimisation
- Material, finish & lighting specification
- Custom furniture & joinery sourcing
- Contractor coordination & site oversight
How It Works
Extending can be stressful.
We make it simple in 4 steps
From first conversation to finished home — one team, one clear process, no surprises.
Tell us your vision
We visit your home, listen to your goals, and carry out a full measured survey. Your brief, budget, and planning requirements are agreed before a single drawing is started.
We design your plans
Our architects create detailed drawings tailored to your lifestyle. Be as creative as you like — leave the technical side to us. We iterate until every detail is exactly right.
We pick the right builder
We tender to our trusted contractor network and review every quote on your behalf. You get competitive pricing and the right team — without taking on that risk yourself.
We take you to the keys
Regular site visits, close contractor management, and quality checks at every stage. When the keys are handed over, your home is finished and completely transformed.
Instant Design Quote
Get an Instant Design Quote
Choose your project type and options to get a personalised design fee estimate in 30 seconds.
Project Type
Select Option
Extension — 3m Rear Extension
Single storey kitchen / living extension, 3m depth, ideal for small gardens
Design Reimagined
Why move when
you can grow?
We specialise in affordable design, transforming dusty lofts into bespoke living areas that breathe new life into your home.
How It Works
Extending can be stressful. We make it simple with these 4 steps
A single, integrated team guiding your project through every stage; no hand-offs, no gaps.
Brief
We start by listening. Through a structured briefing process we establish your goals, budget, programme, and constraints — giving us a clear foundation to build the right approach for your project.
Design Concepts
Our architects develop initial concept options that respond to your brief, the site, and the planning context — presented visually so you can explore possibilities and shape the direction before committing.
Planning
We prepare and submit planning applications, manage pre-application discussions with the local authority, and guide you through the statutory consent process — giving your project the best possible chance of approval.
Technical Drawings
Once planning is secured, we produce a full set of coordinated technical drawings covering architecture, structure, and building services — ready for building regulations approval and contractor pricing.
Construction Quotes
We package the project for tender, identify and approach suitable contractors, evaluate submissions, and advise on appointment — ensuring you get competitive pricing from capable, vetted teams.
Manage
Throughout construction we act as your on-site representative: chairing progress meetings, monitoring programme and cost, reviewing contractor applications, and resolving issues before they become problems.
Handover
We oversee practical completion, manage the snagging process, and ensure all certificates, warranties, and as-built information are in order — so you receive your finished space with complete confidence.
Brief
We start by listening. Through a structured briefing process we establish your goals, budget, programme, and constraints — giving us a clear foundation to build the right approach for your project.
Design Concepts
Our architects develop initial concept options that respond to your brief, the site, and the planning context — presented visually so you can explore possibilities and shape the direction before committing.
Planning
We prepare and submit planning applications, manage pre-application discussions with the local authority, and guide you through the statutory consent process — giving your project the best possible chance of approval.
Technical Drawings
Once planning is secured, we produce a full set of coordinated technical drawings covering architecture, structure, and building services — ready for building regulations approval and contractor pricing.
Construction Quotes
We package the project for tender, identify and approach suitable contractors, evaluate submissions, and advise on appointment — ensuring you get competitive pricing from capable, vetted teams.
Manage
Throughout construction we act as your on-site representative: chairing progress meetings, monitoring programme and cost, reviewing contractor applications, and resolving issues before they become problems.
Handover
We oversee practical completion, manage the snagging process, and ensure all certificates, warranties, and as-built information are in order — so you receive your finished space with complete confidence.
Brief
We start by listening. Through a structured briefing process we establish your goals, budget, programme, and constraints — giving us a clear foundation to build the right approach for your project.
Design Concepts
Our architects develop initial concept options that respond to your brief, the site, and the planning context — presented visually so you can explore possibilities and shape the direction before committing.
Planning
We prepare and submit planning applications, manage pre-application discussions with the local authority, and guide you through the statutory consent process — giving your project the best possible chance of approval.
Technical Drawings
Once planning is secured, we produce a full set of coordinated technical drawings covering architecture, structure, and building services — ready for building regulations approval and contractor pricing.
Construction Quotes
We package the project for tender, identify and approach suitable contractors, evaluate submissions, and advise on appointment — ensuring you get competitive pricing from capable, vetted teams.
Manage
Throughout construction we act as your on-site representative: chairing progress meetings, monitoring programme and cost, reviewing contractor applications, and resolving issues before they become problems.
Handover
We oversee practical completion, manage the snagging process, and ensure all certificates, warranties, and as-built information are in order — so you receive your finished space with complete confidence.
Client Feedback
What Our Clients Say
We measure success by the relationships we build and the results we deliver.
“extnd delivered our flagship workspace on time and exactly to budget. Their attention to detail, proactive communication, and quality of finish exceeded every expectation. I wouldn't hesitate to use them again.”
James Harrington
CEO, FUTR Group
“From feasibility through to handover, the extnd team were professional, transparent, and genuinely invested in the success of our project. The clinic looks exceptional and our patients love it.”
Dr. Sarah Okonkwo
Clinical Director, Meridian Health Group
“Managing a refurbishment in a listed building is notoriously difficult, but extnd navigated every challenge with expertise. The result is a building that beautifully balances its heritage with a modern living environment.”
Robert Ashworth
Property Director, Private Client
“They understood our sustainability ambitions from day one. The energy savings from the Klyk project have already paid back a significant portion of the build cost. Outstanding.”
Priya Mehta
Operations Director, Klyk Ltd
“We were nervous about extending — the horror stories you hear. extnd made the whole process feel effortless. Our new kitchen is exactly what we dreamed of and it came in on budget.”
Laura & Tom Davies
Homeowner, Walthamstow
“The side return was the best decision we ever made for this house. extnd handled the planning, the build, everything. The glazed roof floods the kitchen with light all day. Absolutely love it.”
Mark Osei
Homeowner, Islington
“Our wraparound extension transformed what was a cramped Victorian terrace into a genuinely spacious family home. extnd were honest about timelines, responsive throughout, and the finish is superb.”
Jen & Ali Rashid
Homeowners, Hackney
“We had quotes from four companies. extnd weren't the cheapest, but they were the clearest about what we'd get — and they delivered every bit of it. The loft and rear extension has added years of usability to our home.”
Sophie Hartley
Homeowner, Dulwich
“The garden office extnd designed is genuinely beautiful. We work from home full time and it's changed everything about our day. Delivered faster than expected and to a really high standard.”
Chris & Naomi Webb
Homeowners, Richmond
“What struck me most was how well they listened. They didn't just build what I asked for — they improved it. The dining extension has become the heart of our home.”
Fatima Okafor
Homeowner, Clapham
“Extending both the side and rear felt ambitious but extnd managed the complexity brilliantly. The result is a home that flows properly for the first time since we bought it.”
Dan & Rachel Forde
Homeowners, Battersea
“From planning application to final sign-off, extnd were on top of every detail. Our open-plan kitchen-living space is everything we hoped for. Neighbours keep asking for their number.”
Yemi Adeola
Homeowner, Hackney Downs
“Combining the loft conversion with the rear extension in one project was extnd's suggestion — and they were absolutely right. We now have a home that works for a family of five. Brilliant from start to finish.”
Claire & Simon Ngozi
Homeowners, Greenwich
“We have three kids and needed more space urgently. extnd understood the brief perfectly, were incredibly tidy on site, and finished ahead of schedule. The new extension feels like it was always part of the house.”
Kwame & Abena Mensah
Homeowners, Peckham
See your design get built — exactly as drawn.
Get an instant design quote in under 30 seconds — no obligation. We take on the stress so you don't have to.