Alnwick flat roof extensions, designed and built
From the first sketch to final sign-off, we plan and build flat roof extensions in Alnwick and the surrounding Northumberland area.
- Guide price in AlnwickFrom £19,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsNE66
Flat roof extension prices in Alnwick
These guide figures apply our North East England adjustment (×0.91) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Alnwick: £1,590 to £3,050 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,000 – £22,500 | £22,000 – £28,500 | £28,000 – £37,000 |
| 4 m × 5 m 20 m² | £31,500 – £37,500 | £37,000 – £47,500 | £47,000 – £61,000 |
| 5 m × 6 m 30 m² | £47,500 – £56,000 | £55,500 – £71,000 | £70,500 – £91,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in Alnwick?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
The planning position for a specific Alnwick address depends on its history and any designations, which is why we check it at the first visit.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
What is included
- Falls and outlets designed to drain properly
- Warm-roof design with insulation above the deck
- Parapets or edge trims and flashings to the house
- Lanterns or rooflights with upstands
- Membrane choice: single-ply, EPDM or GRP
Local to Alnwick
Postcode districts we cover around Alnwick include NE66. The same team covers Morpeth (17 miles), Ashington (19 miles), Bedlington (21 miles), Blyth (23 miles), all within easy reach.
For homes towards Tyne and Wear, Whitley Bay is around 29 miles away. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Alnwick
Do I need building regulations approval in Alnwick?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Alnwick, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a flat roof extension in Alnwick?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Can I walk on a flat roof extension?
Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,590 to £3,050 per m² including VAT.
Book a free site visit in Alnwick
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.