House Extension
in St Albans
Compare quotes from vetted St Albans extension builders for single-storey, double-storey and rear extensions. Transparent pricing from £17,500. Free, no-obligation quotes — results in 24 hours.
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How Much Do House Extension Cost in St Albans?
Real prices from completed projects in St Albans and the surrounding area. Costs vary by size, specification and access — use these as a starting guide, then get 3 free quotes for your specific project.
The most popular choice for UK terraces and semis. Adds a kitchen-diner or extra living space at ground level. Typically 3–5m deep, completed in 10–14 weeks.
Get quotes for this →Maximum space gain in a single build — adds a ground-floor room and a bedroom above. Strong ROI in most UK property markets. Requires full planning permission.
Get quotes for this →Ideal for terraced homes with a narrow side alley. Transforms a cramped kitchen into a full-width open-plan space. Often combined with a rear extension.
Get quotes for this →Costs depend on size, spec and access. The best way to know your exact price is to compare 3 quotes from vetted local specialists.
Get free quotes →St Albans pricing note: Eastern England (Essex, Hertfordshire, Cambridgeshire, Suffolk, Norfolk) runs approximately 8–12% above the national average, influenced by proximity to London and strong demand in commuter towns. Prices shown are indicative ranges for St Albans and Eastern. Always get at least 3 written quotes before committing to any builder.
House Extension Specialists Who Know St Albans
St Albans has a thriving home improvement market driven by a strong local economy and a mix of Victorian terraces, post-war housing and contemporary developments. Finding the right builder is key to any successful project.
Every builder in our St Albans network is thoroughly vetted before joining BestBuilders. We verify insurance cover, check trade memberships with bodies such as the FMB and CIOB, and require a minimum of five real customer reviews.
From a small bathroom refurbishment to a major double-storey extension, our vetted St Albans builders cover the full range of residential projects. Request your free quotes today and compare options before making any decisions.
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What St Albans Homeowners Say About Our House Extension Specialists
Rear and side extension combined on our 1970s detached in St Albans. Underfloor heating zoned separately from the rest of the house, A-rated boiler upgraded. Quote of £59520 held to within 1%. CCTV drain survey done before any digging started, no surprises later.
Compared four extension builders through BestBuilders for the St Albans job. Selected on availability rather than price - we needed to start before winter. Trade plates on the kerb so the council parking team did not bother them. Came in at £88120 fitted including site clean and hand-back. Already booking them for the loft conversion next.
Six months later, no settlement cracks anywhere - foundations were clearly done right. Builder we found via BestBuilders in St Albans argued for thicker insulation in the slab - heating bills are visibly lower year-round. Total £59880. Working from home is so much better with the new dedicated space.
House Extension in St Albans — FAQs
Plan Your house extension Project in St Albans
Whether you're researching costs, checking planning rules, or comparing approaches before you commit, our editorial team has produced these guides to help St Albans homeowners make informed decisions about their house extension project.
House Extension Cost Guide
Detailed UK price ranges, regional adjustments and worked examples for house extension projects.
Read House Extension Cost Guide →All House Extension Specialists
Browse our nationwide network of vetted house extension contractors covering all 519 UK towns.
Browse House Extension Specialists →All Cost Guides
Compare prices across extensions, lofts, kitchens, bathrooms, roofing, driveways and solar projects.
View All Cost Guides →Planning your house extension project? Read these guides:
Planning Your House Extension in St Albans
Before you compare quotes, it's worth understanding the full UK price picture for house extension and how St Albans sits within it. The guides below cover average costs, what affects your quote, and how to choose a builder you can trust.
UK House Extension Cost Guide
Full price ranges, worked examples and the factors that move your quote — drawn from real project data across 519 UK towns.
Read the house extension cost guide →House Extension Across the UK
Browse house extension services nationwide, see what's typical in your region, and request quotes from any UK location.
Visit the UK house extension hub →Planning Permission for House Extension in St Albans
Find out whether your house extension needs planning permission in St Albans, what Permitted Development limits apply, and how rules differ in conservation areas, Article 4 zones, and listed-building settings.
Read the house extension planning rules →More homeowner resources: all UK building guides, cost guides, planning permission, comparisons, how-to guides and industry insights.