House Extension Contractors — Delivering Across the UK

The most common issue with house extension projects is a contractor who starts well and then loses focus. They're on site every day for the first two weeks, then they start splitting their time across multiple jobs, and suddenly your project is moving at half speed. By the time you realise what's happening, you're already behind programme and the costs are starting to drift.

Other warning signs: a quote that doesn't include a formal programme, a contract that's just a one-page letter, and a builder who can't tell you exactly which trades will be on site and when. These aren't minor administrative gaps — they're the conditions that allow projects to go wrong.

UK house extensions also have specific regulatory requirements that catch homeowners out. Party Wall Act notices must be served on adjoining owners before work starts on shared boundaries — and the process takes time. Planning permission requirements vary by local authority, and what's permitted development in one area may require full planning in another. Conservation area restrictions can affect materials, roof profiles, and window styles. We know how to navigate all of this, and we factor it into the programme from day one.

Single storey rear extensions are the most common type we build — typically creating an open-plan kitchen-diner or additional living space at the back of the house. We handle the full process: structural design, planning or permitted development confirmation, groundworks, superstructure, roofing, glazing, and internal fit-out. Double storey side extensions follow the same process but add a first-floor bedroom or bathroom above the ground-floor addition.

Wraparound extensions combine a rear and side extension into a single L-shaped addition, which typically requires full planning permission and careful structural design. Basement conversions and extensions are more complex — they involve underpinning, waterproofing, and specialist structural work — but they're one of the most effective ways to add significant floor area to a property without affecting the garden or the street elevation.

We also build orangeries and garden rooms, which sit between a traditional extension and a conservatory — typically with a solid roof, full insulation, and a higher specification of glazing. For loft conversions, see our dedicated loft conversion and extension page. For kitchen-specific extensions, see our kitchen extension page.

All extension work is managed under our construction project management approach — single point of contact, formal programme, and a clear handover process.

We work across the whole of the UK on residential extension projects. We plan mobilisation carefully and price travel honestly — there's no hidden premium for being outside London or the South East. Whether your home is in a city, a market town, or a rural area, you get the same team and the same standard of delivery.

Regional variation in planning policy is something we research before every project. Permitted development rights differ between local authorities, and some areas have Article 4 directions that remove permitted development rights entirely. We check the planning position for your specific property and local authority before the project starts, so there are no surprises mid-build. You can see examples of our completed extension work on our projects page.

Every Vantix Group extension project is backed by a JCT contract, full public liability and professional indemnity insurance, and a formal programme agreed before work starts. You get a single point of contact throughout — not a salesperson who hands you off to a site manager you've never met.

We price transparently. Our quotes are detailed and fixed where the scope is fixed. We don't use low initial quotes to win work and then recover margin through variations. If something changes on site, you hear about it immediately — with a clear explanation and a fair cost.

Read more about how we work on our about page, or get in touch to discuss your extension project.