Penzance, Cornwall
Two-storey rear extension in Penzance
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Penzance and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Penzance is covered from our Cornwall round, including TR18. In Penzance, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Penzance?
A two-storey rear extension in Penzance is priced at £1,870–£2,810 per square metre including VAT as a guide, before kitchen fit-out and fees. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £56,000–£84,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £90,000–£135,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a two-storey rear extension in Penzance?
Here is how the rules in England apply to a two-storey rear extension in Penzance.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Penzance like to extend?
Penzance has Victorian terraces nearer the centre and post-war semis on the edges. Sloping gardens are frequent, which affects floor levels and steps down to the patio.
How a two-storey rear extension in Penzance comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Penzance
We also build two-storey rear extensions in nearby Helston (11.9 miles) and Camborne (12.5 miles).
- Two-storey rear extension in Helston
- Two-storey rear extension in Camborne
- Two-storey rear extension in Redruth
- Two-storey rear extension in Falmouth
- Two-storey rear extension in Truro
Other work in Penzance:
FAQ
Two-storey rear extension questions in Penzance
What postcode areas do you cover around Penzance?
Including TR18, and the surrounding Cornwall area.
How long does a rear extension take to build in Penzance?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What is the 45-degree rule?
Many councils check that a two-storey extension does not cross a 45-degree line drawn from the nearest habitable window of the neighbouring house. We test it at the first drawing.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Can you match the brick or stone on my Penzance house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.