Suffolk
Flat-roof rear extensions in Suffolk
Warm flat roofs with lanterns, parapets and long-life membranes. We design and build rear extensions across Suffolk, from Ipswich and Lowestoft to Bury St Edmunds, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Flat roofs are the usual choice for rear extensions because they stay below first-floor windows and take a lantern neatly. Suffolk mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How much does a flat-roof rear extension cost in Suffolk?
A flat-roof rear extension in Suffolk is priced at £2,010–£3,290 per square metre including VAT as a guide, before kitchen fit-out and fees. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission in Suffolk?
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Suffolk do we work?
FAQ
Questions people ask
How long does a flat roof last?
A well-built single-ply or GRP warm roof typically lasts 25 years or more.
Is a flat roof really flat?
No; it is built to falls so water drains to outlets or gutters.
Can I walk on it?
Not as a balcony without planning permission and a guarding design; it can be accessed for maintenance.
Do you cover all of Suffolk?
We cover 12 towns and districts in Suffolk, including Ipswich, Lowestoft and Bury St Edmunds.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.