Poole at a glance
- Postcode districts
- BH12, BH13, BH14, BH15, BH17, BH18
- Population
- about 151,500 (GeoNames)
- Council area
- BCP Council
- Building approval
- BCP Council building control, or a registered building control approver
- Nearest main town
- Bournemouth, about 5 miles
- Guide price region
- South West (+3% on West Midlands rates)
What makes a good extension roof in Poole?
Extension roofs in Poole are often replaced because the original was built cheaply: thin chipboard decks, little or no insulation and felt turned up the wall without a proper flashing. Twenty or thirty years on, those weaknesses show up as leaks at the back wall and a cold, damp ceiling.
In a city like Poole, flat roofs are commonly found on low-rise post-war blocks of flats or 1960s and 1970s link-detached houses with flat-roofed garages and porches. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage.
How much does a new extension roof cost in Poole?
For Poole we use South West rates: £2,900–£5,050 is the guide for a 20 m² extension roof in EPDM with a new deck and insulation, VAT included. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,900–£5,050 |
| Extension (20 m²), GRP, new deck + insulation | £3,100–£5,550 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £3,100–£5,400 |
| Single garage (18 m²), EPDM rubber | £1,650–£2,900 |
Why does water pond or leak where the extension meets the house?
Usually because the fall runs the wrong way, the abutment detail has failed, or the roof has sagged close to the wall. The junction with the house is the most common leak point on an extension roof.
If the roof falls towards the house, or the deck dips near the wall, water sits against the upstand and finds any weakness in the flashing above. Older roofs often have the felt simply turned up the brickwork with no cover flashing, or a flashing that has pulled out of its joint. A patch will not change a fall. We re-firr or use tapered insulation so water runs away from the wall, then form a new upstand, usually 150 mm above the finished roof, with a flashing chased into the mortar joint.
Rooflights and lanterns are the other weak point. A lantern needs a properly built kerb with the membrane dressed up and under its frame. We rebuild rooflight upstands within the roof job; we do not supply the lantern itself. Our guide to ponding water explains the causes in more depth.
What's included?
- Building control handled where needed, and a written workmanship guarantee
- Free survey of the roof, abutment and room below
- New deck, vapour control layer and warm-roof insulation
- Falls set away from the house wall
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
- Bournemouth · 5 mi
- Wimborne Minster · 5 mi
- Ferndown · 7 mi
- Christchurch · 9 mi
- New Milton · 14 mi
- Dorchester · 20 mi
Extension and kitchen roofs in Poole: questions
Do you cover Poole?
Yes. Poole is part of our Dorset coverage, including postcode districts BH12, BH13, BH14, BH15, BH17, BH18. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Poole?
Where the work needs approval it goes to BCP Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a new extension roof cost in Poole?
£2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
How do I know my extension roof needs replacing rather than repairing?
Repeated leaks, a soft deck, wet insulation or widespread cracking point to replacement. A single defect on a dry, sound roof can usually be repaired.
Is EPDM or GRP better for a kitchen extension?
Neither is better in every case. EPDM suits simple rectangular roofs with few details, while GRP is often chosen where there are rooflights, corners or occasional foot traffic.