Portsmouth price guide
House extension quotes in Portsmouth
Typical local pricing runs £1,900–£3,150 per m² of new floor area, excluding VAT and kitchen fit-out. Here is what drives that range in Portsmouth, and what to check on the quotation in front of you.
Indicative Portsmouth range
£1,900 – £3,150
per m² of new floor area, excluding VAT and kitchen fit-out. Based on a local cost index of 1.09 against the UK average.
Why Portsmouth pricing differs
Access and parking constraints on Portsea Island add cost. Roofing and window trades are in constant demand from coastal weathering.
Dense Victorian terraces in Southsea, island geography with tight streets, and significant exposure to salt-laden wind.
Planning and consent
Portsmouth City Council has conservation areas across Southsea and Old Portsmouth with tight frontage controls.
What to check on a house extension quotation
- Foundation depth allowed for, and the rate if a deeper dig is needed
- Whether structural steel, engineer's fees and building control are inside the price
- The glazing allowance, stated per m² or per unit
- Which items are provisional sums rather than fixed prices
Areas we see quotes from
Homeowners across Southsea, Cosham, Fratton, Drayton, Hilsea and the wider Hampshire area use KnowMyQuote to understand what a contractor has actually priced before committing.
Frequently asked questions
How much does house extension work cost in Portsmouth?
Local pricing typically runs £1,900–£3,150 per m² of new floor area, excluding VAT and kitchen fit-out, based on a higher-than-average cost index of 1.09 for Portsmouth.
Why do quotes in Portsmouth differ so much?
Because they rarely cover the same scope. Access and parking constraints on Portsea Island add cost. Roofing and window trades are in constant demand from coastal weathering. Two quotes for the same job can exclude different items, which is why comparing exclusions matters more than comparing totals.
Do I need planning permission in Portsmouth?
Portsmouth City Council has conservation areas across Southsea and Old Portsmouth with tight frontage controls. Always confirm with the local authority before committing, and apply for a Lawful Development Certificate where the work is permitted development.
How many quotes should I get?
Three, all priced against the same drawings and written specification. Without a common document you are comparing three different buildings, not three prices.
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