Summary
Creating a 3,500 m2 accessible rooftop garden for people and nature on top of a commercial building.
Timescale
A well-known furniture company announced its plans to build a new store in 2013. Construction on site started 4 years later, in November 2017.
The store opened in February 2019 already with seven small-scale green roof bike shelters. The green roof installation started in October 2018. The roof garden opened to the public in March 2019.
Location
Millennium Retail Park, Greenwich, London, UK
What problem did it address?
The company saw this project as an opportunity to demonstrate high levels of sustainability in building design.
Having said that, there is a significant problem with air pollution in Greenwich. In 2008, small particle air pollution caused 150 deaths. Extrapolating UK figures, the cost of air pollution to the residents of the Borough is an estimated £53m p.a.
How did it do it?
The store integrates many sustainability concepts.
Creating habitat for wildlife and achieving BREAM status were two key drivers for the green roof design.
The green roof and roof garden have a wildflower meadow. Log mounds on the roof and bird and bat boxes in the ‘woodland’ garden area enhance the value for wildlife. Seven green roof bike shelters in front of the store provide insect habitats and add floral colour to the shoppers’ welcome.
The roof garden has raised garden beds for school, community and co-worker use and planters as well as paving and artificial turf for community activities.
The rooftop garden is accessible all-year round during opening hours. It provides a space for relaxation and nature exploration.
The solar roof areas collect rain water for flushing toilets, saving up to 50% of drinking water.
Water evaporating from vegetation on the roof creates a natural cooling effect. This reduces energy demand and represents both mitigation and adaptation to climate change
The building incorporates a range of sustainable technologies such as solar power, LED lighting and renewable construction materials.
The store is also accessible via public transport, with 46 bus services per hour serving the site. Facilities to encourage cycling are on site.
Who has benefitted and how?
Cost savings – the green roof is likely to provide 4.5kWh/m2 of cooling during the summer months.
Visitors of the store benefit from access to a greenspace and associated relaxation and wellbeing.
There is also a ‘Learning Lab’. This is a dedicated space for customers, partners and the local community to explore recycling, reducing waste and growing your own food.
What was the cost and how was it funded?
The furniture company financed the green roof. The cost to build the store is stated as £100m in various public sources. The exact cost is confidential.
The cost for the creation of a green roof of this size and style is typically between £110 and £150 per square meter.
Produced with the kind permission of Dusty Gedge.
Evidence of success
The new store helps to inspire and enable people to live a more sustainable life at home. The roof garden is a haven for both people and wildlife. The green roof has become a Green Infrastructure asset for Greenwich.
The store achieved a BREEAM ‘Outstanding’ rating for energy efficiency and sustainability. It has achieved the highest rating of any of the company’s global stores.
The green roof is one of London’s largest roofs for people and nature. It will act as an exemplar and inspiration for future green roofs.
The biodiverse roof featured as an exemplary case study in the new London Green Roof Report.
Difficulties
One of the planning constraints was the expected additional travel and associated air pollution. This made the development controversial. The green roof filtering out some particle pollution, encouraging cycling and use of public transport are all part of the mitigation strategy. The company’s ambition is that 100 % of workers will travel by sustainable means.
Contact details
Dusty Gedge, Director, Livingroofs.org; email: dusty@dustygedge.co.uk
Website and links to relevant resources
BREEAM website https://www.breeam.com/
Living Roofs and Walls from policy to practice 10 years of urban greening in London and beyond, Living Roofs and Mayor of London, 2019
https://livingroofs.org/wp-content/uploads/2019/04/LONDON-LIVING-ROOFS-WALLS-REPORT-2019.pdf
Project partners and contractors
McLaughlin & Harvey Construction Ltd (lead building constructor)
Bridgman & Bridgman (installation of green roof and landscape)
Building Services: Waldeck Associates Ltd
Bauder (green roof supplier)
Green Roof Shelters (provision of green roof bike shelters)
Benchmark street furniture
