- Guide price
- £3,900–£7,100
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
County Down at a glance
- Largest towns
- Bangor, Newtownards, Newry, Banbridge
- Postcode areas
- BT
- Building control
- Ards and North Down Borough Council, Newry, Mourne and Down District Council, Armagh City, Banbridge and Craigavon Borough Council and 1 other council
- Neighbouring areas
- Belfast · County Antrim · County Armagh · County Tyrone
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
How much does a green roof cost in County Down?
Guide prices including VAT at Northern Ireland rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM with sedum green roof | £3,900–£7,100 |
| Extension (20 m²), EPDM, new deck + insulation | £2,450–£4,300 |
Which flat roofs are common in County Down?
Flat roofs in County Down sit on 1930s semis with flat-roofed garages and kitchen extensions, newer estates where the first extension roofs are now being replaced and shops with flat-roofed rear stores below flats. Northern Ireland averages roughly 1,150 mm of rain a year, spread over many wet days, so a roof that sheds water quickly to clear outlets lasts far longer than one that holds puddles. Approximate 1991–2020 regional averages based on Met Office data.
Building control in Northern Ireland
In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where feasible. In County Down the application goes to Ards and North Down Borough Council, Newry, Mourne and Down District Council, Armagh City, Banbridge and Craigavon Borough Council and 1 other council. More on the rules.
Can a green roof go on my existing flat roof?
Only if the existing waterproofing is sound, root-resistant or protected by a root barrier, and has plenty of life left. In most cases it makes more sense to lay a green roof as part of a replacement.
Once the sedum, substrate and drainage layers are down, the membrane underneath is hard to inspect and expensive to repair, because the green layers have to be lifted to get to it. Putting a green roof on an ageing covering risks paying for the greenery twice. Our repair or replace guide helps you judge whether your current roof is a sensible base.
As for planning, re-covering a house roof normally needs no application if its appearance doesn't change materially. Because a green roof does change how a roof looks, check with your council, especially for listed buildings, conservation areas and roofs that are easily seen. The planning guide has more.
Which towns in County Down do we cover?
- Bangor
- Newtownards
- Newry
- Banbridge
- Dundonald
- Holywood
- Downpatrick
- Comber
- Carryduff
- Warrenpoint
- Newcastle
- Donaghadee
Green and sedum roofs in County Down: questions
Which towns in County Down do you cover?
All of County Down. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a green roof cost in County Down?
£3,900–£7,100 for a 20 m² insulated extension roof finished as a sedum green roof, at Northern Ireland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in County Down?
It depends on where the roof is: in County Down that's Ards and North Down Borough Council, Newry, Mourne and Down District Council, Armagh City, Banbridge and Craigavon Borough Council and 1 other council. In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. We confirm which applies at the survey.
Can I walk on a green roof?
Only for maintenance, and only where it is safe. Most extensive green roofs on homes aren't designed as roof terraces, and a terrace generally needs planning permission and edge protection.
Can you put a sedum roof on a garage?
Often, yes, if the structure is strong enough. Many older garage roofs have light timbers, so a structural check comes first and strengthening may be needed.
Does a green roof leak more than a normal flat roof?
No, as long as it is built correctly. The waterproofing beneath is what keeps water out, and the green layers protect it from sun and weather. The main risk is building it on a weak or ageing membrane.
Everything about green and sedum roofs → · All flat roofing in County Down →