Holywood at a glance
- Postcode districts
- BT18
- Population
- about 13,109 (GeoNames)
- Council area
- Ards and North Down Borough Council
- Building approval
- Ards and North Down Borough Council building control
- Nearest main town
- Belfast, about 5 miles
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
Why choose a green roof in Holywood?
In a place like Holywood, many people look out over a flat extension or garage roof from upstairs. Grey felt or rubber isn't much of a view, and a sedum roof turns it into something green that changes colour through the seasons and flowers in summer.
Holywood's flat roofs are mostly on bungalows with flat-roofed side extensions and dormers, with plenty on low-rise post-war blocks of flats too. 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.
How much does a green roof cost in Holywood?
For Holywood we use Northern Ireland rates: £3,900–£7,100 is the guide for a 20 m² insulated extension roof finished as a sedum green roof, VAT included. 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 |
How long does a green roof last and how much maintenance does it need?
A well-built extensive green roof needs one or two maintenance visits a year, and the plant layer can help protect the membrane from sunlight and temperature swings.
Typical maintenance means pulling out weeds and tree seedlings before they root, clearing outlets and the gravel strips around edges, filling in any bare patches, and adding a slow-release feed if the sedum looks thin. Sedum is drought-tolerant once established, but newly laid blankets may need watering in a long dry spell during the first season.
The waterproofing underneath has the same expected life as on any other roof of that system. A green roof also slows down rainwater run-off from the roof and, when sedum flowers, attracts bees and other insects. Some councils encourage green roofs for those reasons, so it is worth mentioning one in a planning application for a new extension. Our maintenance guide covers routine checks.
What's included?
- Root-resistant membrane or separate root barrier
- Pre-grown sedum blankets laid and watered in
- Drainage layer, filter and lightweight growing medium
- Structural check of joists, deck and supports
Building control in Northern Ireland
In Northern Ireland, Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where that's feasible. The district council's building control should be contacted before work starts, and we prepare the details it asks for. More on the rules.
Which nearby areas do we also cover?
Green and sedum roofs in Holywood: questions
Do you cover Holywood?
Yes. Holywood is part of our County Down coverage, including postcode districts BT18. 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 Holywood?
Where the work needs approval it goes to Ards and North Down Borough Council building control. 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 green roof cost in Holywood?
£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.
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.
Do I need to water a sedum roof?
Usually only in the first season, during long dry spells, while the blankets establish. After that, sedum copes with dry weather well.