House Extension
in Portsmouth
Compare quotes from vetted Portsmouth 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 Portsmouth?
Real prices from completed projects in Portsmouth 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 →Portsmouth pricing note: Southern England (Hampshire, Dorset, West Sussex) sits around 10–15% above the national average. Coastal locations and areas with restricted site access can attract additional charges from contractors. Prices shown are indicative ranges for Portsmouth and Southern. Always get at least 3 written quotes before committing to any builder.
House Extension Specialists Who Know Portsmouth
Portsmouth 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 Portsmouth 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 Portsmouth, 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 Portsmouth Homeowners Say About Our House Extension Specialists
Found an excellent builder through BestBuilders for our extension project. The quote process was straightforward, the builder was professional throughout and the finished result exceeded our expectations.
We used BestBuilders to find a loft conversion specialist. Received 3 competitive quotes within 48 hours and the builder we chose delivered on time and on budget. Highly recommended.
Good experience overall. The kitchen renovation was completed to a high standard. Minor delays on materials but the builder kept us informed. Would use BestBuilders again.
House Extension in Portsmouth — FAQs
House Extension Near Portsmouth
We also connect homeowners with vetted house extension specialists in towns surrounding Portsmouth.