House Extension
in Grantham
Compare quotes from vetted Grantham extension builders for single-storey, double-storey and rear extensions. Transparent pricing from £16,500. Free, no-obligation quotes — results in 24 hours.
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How Much Do House Extension Cost in Grantham?
Real prices from completed projects in Grantham 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 →Grantham pricing note: East Midlands building costs are broadly in line with the national average. Prices in Nottingham, Leicester and Derby are competitive, with good availability of vetted local contractors across the region. Prices shown are indicative ranges for Grantham and East Midlands. Always get at least 3 written quotes before committing to any builder.
House Extension Specialists Who Know Grantham
Home renovation activity in Grantham 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 Grantham 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 Grantham 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 Grantham Homeowners Say About Our House Extension Specialists
Rear and side extension combined on our 1990s semi in Grantham. 24m² rear with structural opening through to the existing kitchen and a steel beam above. £80860 across 14 working weeks. FMB-credentialed builder, structural calcs done in-house.
Compared four extension builders through BestBuilders for the Grantham job. Selected on availability rather than price - we needed to start before winter. Steel goalpost frame craned in on day 8, then fixed within 24 hours. Final invoice £60940 - within 2% of the original quote. Moved out for two weeks during the demolition and steel install, the rest was bearable.
Six months later, no settlement cracks anywhere - foundations were clearly done right. Builder we found via BestBuilders in Grantham reused the original chimney as a feature inside the new space - clever bit of design. Total £76260. Decided to stay rather than move - the extension solved the space problem entirely.
House Extension in Grantham — FAQs
Plan Your house extension Project in Grantham
Whether you're researching costs, checking planning rules, or comparing approaches before you commit, our editorial team has produced these guides to help Grantham 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 Grantham
We also connect homeowners with vetted house extension specialists in towns surrounding Grantham.
Planning Your House Extension in Grantham
Before you compare quotes, it's worth understanding the full UK price picture for house extension and how Grantham 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 Grantham
Find out whether your house extension needs planning permission in Grantham, 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.