A sustainable approach to the development of Cabot Circus was adopted from the outset, transforming a former brownfield site into a thriving city centre with a barrier-free public environment and improved transport options.

Environmental considerations then followed throughout the design and construction of Cabot Circus – helping to secure Bristol's future as a truly sustainable city.

And now Cabot Circus has become the first UK retail project of its kind in the UK to achieve the highest BREEAM rating of "excellent", following a detailed environmental assessment.

Located on a 36-acre site, the centre features a mix of nine different uses – including retail, catering, leisure, offices, housing, student accommodation, a hotel and car park.

It is the largest retail-led city centre urban regeneration project in the UK and has been designed by seven different firms to create architectural variety and a cosmopolitan streetscape.

The scheme is integrated into the city through a series of open streets and squares, and features a dramatic glazed roof above the central open space.

Bob De Barr, Bristol Alliance project director, pictured below right, said: "We have earned one of the industry's highest sustainability ratings, BREEAM Excellent, through our commitment to delivering all possible sustainable measures throughout every stage of the project's construction. It is a demonstration of our commitment to be as sustainable as possible."

Design philosophy

The overall design philosophy for Cabot Circus is focused on extended existing spaces and creating an outdoor environment - moving away from the typical sanitised "mall" shopping experience. Natural ventilation is one the scheme's most recognisable characteristics, saving an estimated 5 million kilowatt hours per annum, equivalent to the energy consumed by 450 homes.

As there are no doors or gates, the need for heating and cooling – and associated energy demands – are eliminated. The curved glass roof has been designed to "hover" above much of the central area, creating a light, open environment but also providing shoppers with protection from the elements.

The layout of the buildings themselves has also been designed to encourage the natural funnelling of air to avoid the need for smoke ventilation and air-conditioning systems. In addition, architectural design has maximised opportunities for passive solar gain to help harness the potential for renewable energy generation in the future.

Waste minimisation

Locally sourced materials have been used wherever possible during the construction of Cabot Circus, including natural stone, brick, steel and glass. Timber and recyclable materials were specified over less recyclable materials.

During the demolition phase – which saw the de-construction of the 16-storey Tollgate House – over 90 per cent of waste generated on site was recycled. Emphasis was placed on re-using waste materials elsewhere on site to minimise carbon emissions generated by transportation, as well as traffic congestion.

There has also been a focus on using materials containing a high level of recycled content, helping to support the market for recycled products and divert waste from landfill. Sixty per cent of the structural steel used is derived from recycled sources.

Sustainability targets

The Bristol Alliance set a strict 80 per cent recycling target for all retailers during the internal fit-out stage and produced a shop-fit guide to help achieve this. Environmental guidance was provided to all tenants, including management training and a green issues awareness programme.

Water and energy

Particular emphasis has been placed on the efficient use of resources throughout Cabot Circus and a number of energy- and water-saving measures have been integrated into the design.

Street lighting is subtle and high-efficacy lamps have been used where appropriate. Back-of-store lighting is controlled by presence detectors and the car park energy usage costs could be halved through the use of intelligent controls and low-energy lamps.

One of the innovative water efficiency features is the rainwater-harvesting system, which captures rainwater from the canopies for re-use in flushing toilets and irrigation throughout the scheme.

Bright future

As well as generating 3,500 construction jobs, more than 4,000 permanent jobs were created by Cabot Circus, providing a wealth of opportunities for local people and a welcome boost to the city's economy.

More than 24 million people are expected to pass through Cabot Circus during the first year of opening and current footfall is averaging 500,000 visitors each week – representing a significant increase in tourism and investment.

The scheme has added spark and new life to the city centre, elevating Bristol to its rightful position as the shopping capital of the South West.

Landmark sculpture

A new sculpture at the gateway to Cabot Circus was recently unveiled to mark the completion of the scheme's sustainability agenda.

Twist, a 65.7ft-high sculpture created by artists Ackroyd and Harvey, takes the form of an elegant illuminated tower and turbine, powered solely by wind and solar energy.

Commissioned by the Bristol Alliance as part of a wide-ranging public art programme for Cabot Circus, the tower is sited in the centre of the Newfoundland Circus on the main approach into Bristol from the M32. The work has a low environmental impact and is intended to engage with a city that aims is responding to urban pressures to become one of Europe's leading green capitals.

The materials chosen to create the landmark structure are equally sustainable.

Clad with an intensive layering of thin dark grey slates, a waste material from the roofing industry, the strata-like tower supports a glazed solar canopy, from which rises a four metre-high vertical axis wind turbine.