House Extension
in St Helens
Compare quotes from vetted St Helens 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 St Helens?
Real prices from completed projects in St Helens 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 Helens 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 St Helens and Merseyside & North Wales. Always get at least 3 written quotes before committing to any builder.
House Extension Specialists Who Know St Helens
Home renovation activity in St Helens continues to grow year on year. The area's varied housing stock, from older stone-built properties to new-build estates, means there is always strong demand for skilled, experienced local builders.
Before any builder appears on our St Helens platform, we carry out a full vetting check covering public liability insurance, trade qualifications, company registration and verified customer feedback. Only builders who pass every stage are listed.
Our St Helens builder network covers extensions, loft conversions, kitchens, bathrooms, roofing, driveways and more. Get up to 3 free, no-obligation quotes within 24 hours and choose the builder that best fits your project and budget.
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What St Helens Homeowners Say About Our House Extension Specialists
Larger Permitted Development extension on our 1960s detached in St Helens. Cantilevered glass roof at the threshold with no internal columns - clean look. Final invoice £80410 over 17 weeks. Full insurance-backed warranty in writing on the structural works.
Compared four extension builders through BestBuilders for the St Helens job. Selected on the depth of the spec - 28 pages versus the cheapest at 4 pages. CDM regs followed properly - principal designer and contractor roles defined in writing. Came to £83930 across 16 weeks. Insurance happy with the structural certificate.
Through a full freeze-thaw winter, no movement around the new openings. Builder we found via BestBuilders in St Helens integrated MVHR ducting into the new ceiling void - no soffit boxes needed. Total £61980. Family logistics transformed - everyone has space to themselves.
House Extension in St Helens — FAQs
Plan Your house extension Project in St Helens
Whether you're researching costs, checking planning rules, or comparing approaches before you commit, our editorial team has produced these guides to help St Helens 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 St Helens
We also connect homeowners with vetted house extension specialists in towns surrounding St Helens.
Planning Your House Extension in St Helens
Before you compare quotes, it's worth understanding the full UK price picture for house extension and how St Helens 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 Helens
Find out whether your house extension needs planning permission in St Helens, 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.