Blue roof, Kings Cross, London
- Blue roof
- Living roof
This innovative 300m2 roof in the North London area of King’s Cross was completed in 2020. It combines the triumvirate of sustainable roofing: blue, green…
Blue roofs – the frontline against flash flooding
Blue roof is the common name for roofs that conform to sustainable drainage systems (SuDS) regulations. They aren’t actually ‘blue’. They restrict the rate that water runs off from a building into storm drains or natural watercourses after a downpour, thus minimising the impact on water quality, biodiversity and flooding.
Pritchard & Pritchard is the leading expert in design, install and maintenance of all types of SuDS-compliant blue roofs, including blue-green roofs and paved blue roofs.
Our SuDS specialists have been installing blue roofs since 2012.
Blue-green roofs
A blue roof incorporates a sustainable drainage system (SuDS), which retains water following a downpour and manages how the water is dispersed to prevent the damaging run off.
Commonly a green roof is installed above the blue roof – sometimes called a blue-green roof. This hits the dual development targets of increasing SuDS and green roofs. An example blue-green project in Kings Cross is shown adjacent.
London’s Sustainable Design and Construction SPG provisions (2014) states: “New development should incorporate Sustainable Urban Drainage Systems and green roofs where practical with the aim of achieving a Greenfield run-off rate, increasing biodiversity and improving water quality.”
Paved blue roofs and roof gardens
A blue roof or SuDS-compliant roof can easily be incorporated into a rooftop garden or terrace.
The adjacent image, from a Barclay Homes development, shows Pritchard & Pritchard’s paving team laying slabs on adjustable pedestals over a blue roof system.
For more information on pedestal paving see: rooftop gardens and podiums.
Blue roof maintenance
Maintenance plans for blue roofs depend on the type of roof with which it is combined.
The main distinction is that blue roof systems include sophisticated drainage systems that should be regularly checked for blockages.
For details of P&Ps maintenance services, see: Living roof maintenance for more information.
If your blue roof has structural or aesthetic issues, call in our Living Roof Doctor for a consultation.
Explainer / FAQ
- What is a blue roof?
- What is the difference between a blue, brown and green roof?
- What are the benefits of a blue roof?
- What are the planning considerations with blue roofs?
- How much maintenance does a blue roof require?
All your blue roof questions are answered in our extensive living roof FAQ.
Latest case studies
Roof restoration and maintenance, City of London
- Living roof
- Maintenance
Pritchard & Pritchard’s maintenance team were tasked with restoring four roofs where the weeds had taken over, to their former glory. Replanting completed 2019; maintenance…
Wimbledon Grounds combats flooding and pollution with 14,000 square metres of SuDS blue roofs and podiums
- Podium & Roof gardens
- Podium garden
- Roof garden
London’s largest blue roof. Exemplar storm-water-management roofing project Every roof in the development is blue and green (wildflower roofs) Half of the roofs are also…
