Pitched roof extensions in St Helens: design, approvals and build
From the first sketch to final sign-off, we plan and build pitched roof extensions in St Helens and the surrounding Merseyside area.
- Guide price in St HelensFrom £21,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsL34, L35, WA9, WA10, WA11
Do I need planning permission in St Helens?
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 St Helens 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).
Pitched roof extension prices in St Helens
Prices below are for St Helens, using the North West England factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.
Typical rates in St Helens: £1,760 to £3,320 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £21,000 – £25,000 | £24,500 – £31,500 | £31,000 – £40,000 |
| 4 m × 5 m 20 m² | £35,000 – £41,000 | £40,500 – £52,500 | £52,000 – £66,500 |
| 5 m × 6 m 30 m² | £52,500 – £61,500 | £61,000 – £78,500 | £78,000 – £100,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Local to St Helens
Across L34, L35, WA9, WA10, WA11, WA12, we can visit, measure and advise. Neighbouring towns we cover include Prescot (3 miles), Huyton (5 miles), Newton-le-Willows (5 miles), Golborne (6 miles).
For homes towards Greater Manchester, Ashton-in-Makerfield is around 4 miles away. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
Included in a typical project
- Roof windows positioned for light and ventilation
- Insulation to current building regulations
- Lead or proprietary flashings to the main wall
- Vaulted ceilings or flat ceilings with storage above
- Roof design matched to the existing pitch and tiles
From first visit to completion
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about pitched roof extensions
How long does a pitched roof extension take to build in St Helens?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Will my neighbours in St Helens be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do you cover all of St Helens?
Yes. We cover St Helens and the surrounding parts of Merseyside. Site visits are free and there is no obligation.
How much does a pitched roof extension cost?
Our guide range is about £1,760 to £3,320 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
Can I have a vaulted ceiling?
Yes. A vaulted ceiling with roof windows is one of the main reasons to choose a pitched roof. It needs insulation between and under the rafters to meet the building regulations.
Book a free site visit in St Helens
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.