Two-storey extensions in Portsmouth
Planning a bigger home in Portsmouth? Compare extension types and guide prices below, then book a free site visit.
Portsmouth at a glance
- Postcode districts
- PO1, PO2 and PO3
- Area
- Hampshire, England
- Price region
- South East England
- Nearest towns
- Southsea (1.1 miles), Gosport (1.7 miles), Cosham (3.5 miles), South Hayling (5.1 miles)
- Distance to Southampton
- about 15.5 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
We cover postcode districts PO1, PO2 and PO3 in and around Portsmouth, along with neighbouring Southsea, Gosport and Cosham.
Extensions available in Portsmouth
Two-storey rear extensions
Portsmouth guide price from £61,500, Standard spec.
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Two-storey side extensions
Guide from £94,500 in Portsmouth, including VAT.
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Two-storey wraparound extensions
Design, approvals and build for Portsmouth homes. Guide from £132,500.
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Part single, part two-storey extensions
Portsmouth guide price from £79,000, Standard spec.
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Extensions over a garage
Guide from £34,500 in Portsmouth, including VAT.
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First-floor extensions
For homes in Portsmouth: typical guide from £27,500.
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Two-storey extensions for semi-detached houses
For homes in Portsmouth: typical guide from £61,500.
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Two-storey extensions for detached houses
Portsmouth guide price from £94,500, Standard spec.
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Kitchen extensions with bedrooms above
Design, approvals and build for Portsmouth homes. Guide from £61,500 (before kitchen units).
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Extra bedroom and en-suite extensions
Design, approvals and build for Portsmouth homes. Guide from £61,500 (plus en-suite).
Learn moreWhich type suits your house?
Which type suits your house in Portsmouth depends mostly on where you have room. A deep garden points to a rear extension; space beside the house points to a side or over-garage extension; a house that already has a single-storey extension can often take a first floor on top.
Also available in Hampshire
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Portsmouth
Portsmouth is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in Portsmouth
Do you cover Portsmouth?
Yes. We cover Portsmouth (PO1, PO2 and PO3) and the surrounding area, including Southsea and Gosport. The first site visit is free.
What does a two-storey extension cost in Portsmouth?
Using our South East England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £61,500–£83,000 including VAT. An extension over a garage is about £34,500–£50,500.
Which other places near Portsmouth do you cover?
Everywhere around it, including Southsea (1.1 miles), Gosport (1.7 miles) and Cosham (3.5 miles), and the rest of Hampshire.