Two-storey extensions in Portland
We design, get approval for and build two-storey extensions in Portland and the surrounding area. Choose the type of extension below or book a free site visit.
Portland at a glance
- Postcode districts
- DT5
- Area
- Dorset, England
- Price region
- South West England
- Nearest towns
- Weymouth (3.3 miles), Dorchester (10.3 miles), Bridport (17.9 miles), Swanage (21.6 miles)
- Distance to Bournemouth
- about 26.9 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 Portland (DT5) and the places around it, including Weymouth (3.3 miles), Dorchester (10.3 miles) and Bridport.
Extensions available in Portland
Two-storey rear extensions
Guide from £57,500 in Portland, including VAT.
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Two-storey side extensions
Design, approvals and build for Portland homes. Guide from £88,500.
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Two-storey wraparound extensions
Guide from £124,000 in Portland, including VAT.
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Part single, part two-storey extensions
From £74,000 in Portland. Free visit to firm it up.
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Extensions over a garage
Design, approvals and build for Portland homes. Guide from £32,500.
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First-floor extensions
Portland guide price from £26,000, Standard spec.
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Two-storey extensions for semi-detached houses
Design, approvals and build for Portland homes. Guide from £57,500.
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Two-storey extensions for detached houses
Design, approvals and build for Portland homes. Guide from £88,500.
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Kitchen extensions with bedrooms above
Design, approvals and build for Portland homes. Guide from £57,500 (before kitchen units).
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Extra bedroom and en-suite extensions
From £57,500 (plus en-suite) in Portland. Free visit to firm it up.
Learn moreWhich type suits your house?
If you're not sure which type fits, that's what the free visit is for. We'll sketch the realistic options for your house in Portland, with a rough idea of the approval route and cost for each.
Also available in Dorset
- 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 Portland
Portland 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 Portland
Do you cover Portland?
Yes. We cover Portland (DT5) and the surrounding area, including Weymouth and Dorchester. The first site visit is free.
What does a two-storey extension cost in Portland?
Using our South West 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 £57,500–£78,000 including VAT. An extension over a garage is about £32,500–£47,500.
Which other places near Portland do you cover?
Everywhere around it, including Weymouth (3.3 miles), Dorchester (10.3 miles) and Bridport (17.9 miles), and the rest of Dorset.