Situation

B&Q, which operates 350 stores in the UK, is part of Kingfisher plc. Through its One Planet sustainability programme, B&Q has been cutting carbon, saving water, reducing waste and sourcing sustainable timber since 2007. Hammerson’s sustainability framework, Positive Places, aims to create retail destinations that deliver positive impacts economically, socially and environmentally.  

When B&Q approached Hammerson about an Eco Learning Store at Cyfarthfa Retail Park, Hammerson welcomed the opportunity to collaborate to build a large-scale, sustainable and low-energy store. Hammerson and B&Q agreed a set of best practice sustainability targets at an early stage of development. These targets go above and beyond local planning requirements and support Hammerson and B&Q’s sustainability objectives. Issues covered include energy efficiency, embodied carbon, recycled content, responsibly sourced timber, waste management, water consumption, biodiversity and climate change adaptation.

Fulfilling B&Q’s aspirations meant that the new store must:

• Demonstrate a sustainable approach that is replicable and scalable
• Be flexible and future proofed to respond to changing market needs
• Be commercially viable
• Be subject to a post-occupancy evaluation after 18 months.

The 4,200m² Eco Learning Store, which opened in 2014, was designed by Powell Dobson Architects and built by BAM Construction. The store won the Property Week Sustainability Achievement Award in 2015, with Hammerson and B&Q praised by the judges for their collaborative and holistic approach.

Actions and benefits

Key sustainability features, being evaluated for potential roll out to other stores, include:

• 34% reduction in gas consumption resulting from the Transpired Solar Collector system, which harvests the sun’s heat to warm the store, and solar thermal panels, which provide heat for domestic hot water.
• 50% of available roof area covered with an ecologically diverse, plant rich green roof, supporting biodiversity, improving thermal insulation and reducing local flood risk by slowing rainwater run-off rates. The amount of green roof space was affected by factors such as weight, cost, access and equipment.
• 50% of water provided through a rainwater harvesting system to flush toilets and urinals, and supply the garden centre irrigation system.
• 23% less embodied carbon than industry benchmarks for similar retail developments (0.336 tCO₂e per m² ‘cradle to gate’ including transport), through the use of steel cladding rather than aluminium, insulation with recycled content and cement replacement in the structural concrete.
• 15% better energy efficiency than required by Building Regulations (2010 Part L), with high thermal efficiency in the building fabric (air tightness of 2.47m³/hr/m²), energy efficient LED lighting, automatic daylight dimming and sun pipes that channel light from the roof through highly reflective pipes.
• 100% of timber from guaranteed sustainable sources, as certified by the Forest Stewardship Council (FSC)
• 90% of construction waste diverted from landfill.
• Climate change adaptation measures included the green roof and Grasscrete in some areas of the car park, as part of a sustainable urban drainage scheme, slowing rainwater run-off and so reducing flood risk.
• Locally procured materials to benefit the local economy and cut transport CO₂ emissions, including steel from Port Talbot, cladding and roofing from Cardiff, insulation from Barry, and pulverised fuel ash concrete replacement sourced from Port Talbot and manufactured in Cardiff.

Financials

Commercial Transpired Solar Collector systems typically have a three- to ten-year payback, depending on whether:

• The project is a new build or a refurbishment.
• The system operates in series with or parallel to a conventional space heating system. If the system is in series, only the incremental cost of the collector and interfaces need to be accounted for in the payback.
• Contractors increase rates for perceived risk associated with new technology.

For example, the 280m² Transpired Solar Collector installed on the Eco Learning Store is expected to:

• Produce direct gas savings of 37MWh per annum and other system benefits from recirculation and night cooling.
• Deliver annual savings of circa £3,500, based on conventional system overall efficiency of 80%, average gas costs of £0.04 per kWh and including the Renewable Heat Incentive.
• Cost £36,000, although this doesn’t account for the financial savings associated with the installation of a smaller heating system.
• Estimated to achieve payback in less than 10 years.

The Transpired Solar Collector at Cyfarthfa Retail Park was an innovative demonstration project rather than a pure commercial solution. It attracted funding from the Welsh European Funding Office to inform future design and installation of similar systems in the UK on a commercial basis. Performance of the Transpired Solar Collector is being monitored by Cardiff University and Tata Steel.

Find out more

Richard Quartermaine

Environmental Manager

http://sustainability.hammerson.com/