House Extension
in Runcorn
Compare quotes from vetted Runcorn extension builders for single-storey, double-storey and rear extensions. Transparent pricing from £14,500. Free, no-obligation quotes — results in 24 hours.
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How Much Do House Extension Cost in Runcorn?
Real prices from completed projects in Runcorn 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 →Runcorn pricing note: Merseyside and North Wales prices are broadly competitive, sitting 5–10% below the national average. Liverpool projects may attract minor access surcharges; rural North Wales locations can add logistics costs for specialist trades. Prices shown are indicative ranges for Runcorn and Merseyside & North Wales. Always get at least 3 written quotes before committing to any builder.
House Extension Specialists Who Know Runcorn
Runcorn is one of the UK's most active home renovation markets. With a diverse range of properties across the area, from period homes to modern new builds, local builders need to be versatile, skilled, and reliable.
BestBuilders vets every builder in our Runcorn network. We check for public liability insurance, relevant trade qualifications (CIOB, FMB, Gas Safe, NICEIC), and a minimum of five verified customer reviews before any builder can appear on our platform.
Whether you are planning a rear extension, a loft conversion, or a full kitchen renovation in Runcorn, we will connect you with the right specialist within 24 hours. All quotes are free and there is no obligation to proceed.
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What Runcorn Homeowners Say About Our House Extension Specialists
Conservation-area sympathetic extension on our 1960s detached in Runcorn. Cantilevered glass roof at the threshold with no internal columns - clean look. Final invoice £80900 over 17 weeks. Full insurance-backed warranty in writing on the structural works.
Compared four extension builders through BestBuilders for the Runcorn job. Final pick had a structural engineer on staff, not subcontracted. CDM regs followed properly - principal designer and contractor roles defined in writing. Came to £84400 across 16 weeks. Insurance happy with the structural certificate.
Past a year and the extension is the most-used part of the whole house. Builder we found via BestBuilders in Runcorn integrated MVHR ducting into the new ceiling void - no soffit boxes needed. Total £62400. Family logistics transformed - everyone has space to themselves.
House Extension in Runcorn — FAQs
Plan Your house extension Project in Runcorn
Whether you're researching costs, checking planning rules, or comparing approaches before you commit, our editorial team has produced these guides to help Runcorn 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:
House Extension Near Runcorn
We also connect homeowners with vetted house extension specialists in towns surrounding Runcorn.
Planning Your House Extension in Runcorn
Before you compare quotes, it's worth understanding the full UK price picture for house extension and how Runcorn 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 Runcorn
Find out whether your house extension needs planning permission in Runcorn, 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.