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OUR SERVICES
Extension Builders Hertfordshire
More Room to Live, Without Moving House
Build Trust are extension builders serving homeowners across Hertfordshire, from single-storey kitchen extensions to full double-storey additions. We manage planning permission, architect drawings, structural build, groundworks and decoration under one roof — so you get one trusted contractor, not a chain of trades to coordinate. We work across Stevenage, Hertford, Welwyn Garden City, Potters Bar, Cheshunt and Berkhamsted.
What We Build
House Extensions Built Around How You Live
Rear & Kitchen Extensions
Open-plan kitchen diners that pull light and garden views into the heart of the home.
Single & Double-Storey
Extra bedrooms, bathrooms or living space, built to match your existing roofline and brick.
Open-Plan Living
Knock-through layouts that turn a house into a home built for family life.
Why build trust
End-to-End, From Drawings to Decoration
A house extension touches almost every trade in the book. We coordinate every one of them, so nothing falls through the cracks between contractors.
From the first planning permission application through to the final coat of paint, one team stays accountable for the whole build — including a live on-site design pass once the shell is up, so the finish matches the ambition of the extension itself.
Trusted & Accredited
Backed by the Industry's Highest Standards
Federation of Master Builders membership is earned through a vetting and inspection process — a recognised mark of quality, professionalism and proper standards. For you, it's added reassurance that you're working with a builder who takes both workmanship and client care seriously.
A Secure Process from Groundbreak to Handover
In line with our pragmatic, professional approach, we manage every technical detail to move you from planning to completion with ease:
1.
Intelligent Planning & Assessment
We evaluate your property's potential and coordinate with architects to ensure the design meets both aesthetic ambition and practical function.
2.
Dedicated Project Management
A dedicated lead keeps our team on schedule, maintaining a clean and respectful site that minimises disruption to your world.
3.
Rigorous Quality Handover
We conduct a final, comprehensive quality check before handing over the keys to a new space perfectly suited to your lifestyle.
10-Year
Workmanship promise on every build
Days
Live on-site design turnaround
100%
Project-managed, start to finish
10-Year
Workmanship promise on every build
Days
Live on-site design turnaround
100%
Project-managed, start to finish
Real voices
Homeowners speak about their experience
Ready When You Are
Ready to Extend Your Home?
Book a free consultation and get honest pricing on your extension — no obligation.
FAQs
Transparency is our promise. We've addressed the questions clients ask most. For anything else, our team is a quick call away.
Do I need planning permission for a house extension?
Often not — many single-storey rear extensions fall under permitted development. We assess this at survey stage and manage the application if one is needed.
How long does a house extension take?
Most single-storey extensions run 10–14 weeks once on site; double-storey projects typically take longer. We give you a realistic programme before work starts.
Can you match the extension to our existing brick?
Yes — brickwork is one of our in-house skills, and matching an extension to an older property's bond and colour is something we take seriously.
What does a free consultation involve?
A no-obligation visit to your home to discuss what you want, assess feasibility, and give you an honest steer on cost and timeline.
Get in Touch
Tell Us About Your Space
Send a few details and we'll be in touch to arrange your consultation. Prefer a call? Hit "Relax, We'll Call You" and we'll do the rest.
+44 7480 777 253
25 Town Square, Stevenage, SG1 1BP
Extensions, renovations, and landscaping across Hertfordshire, managed by one team.
Location
25 Town Square
Stevenage
SG1 1BP