A new building under construction at Cape Town’s V&A Waterfront is among the first commercial buildings in the world to use ecobrick technology.

Recycled beverage bottles, including the typical 2 𝓵 bottles, are being used as ecobricks in the construction of The Ridge, a custom-designed green building to accommodate the Cape Town offices of international professional services firm Deloitte.

The bottles are filled to constant density with waste plastics and can take up to 250 small chips packets or 56 shopping plastic bags in each bottle. They weigh an average of 600 g. The ecobricks were donated by community volunteers and scholars from and around Cape Town.

The main contractor does quality control on site. Density is important, so each ecobrick has to be checked for compliance. The bottles are then used as void formers.

“To the best of our knowledge, we are the first large commercial building to be using this regenerative technology,” says V&A Waterfront development director Mark Noble.

“It’s a very environmentally conscious way of not only burying waste but also replacing environmentally insensitive building materials,” he tells Engineering News & Mining Weekly.

Void formers are used to ‘fill’ space and reduce the amount of concrete required.

“Usually, big chunks of expanded polystyrene are used. Firstly, it’s a virgin plastic. It doesn’t biodegrade at all. When it is shaped to fit and then cut on site, a lot of the waste – little white balls – are blown into stormwater systems and washed out to sea. They are in the system forever,” explains Noble.

The switch to ecobricks is a way of mitigating this kind of waste.

Noble says the developers used ecobricks in the non-load-bearing parts of the building, such as the floor slabs in the central toilet areas.

The Ridge project will use 12 000 ecobricks. This will lead to a displacement of 57 t of concrete in the absence of any other common void-forming material being used.

The project has been seen as a win-win for developers and the community.

As an existing partner of the V&A, Ian Dommisse, of Ecobrick Exchange, has involved schools and communities in Cape Town in the recycling and making of the ecobricks. The Eros School for physically and mentally challenged children, in Athlone, together with Edgemead Primary and Capricorn Primary, in Muizenberg, as well as Tracy Pretorius, a self-confessed eco-warrior, has helped to churn out the ecobricks.

Any kind of everyday-use plastic, such as sweet wrappers, chips packets and plastic bags, can be used to fill the 2 𝓵 bottles. Communities, schools and nongovernmental organisations can sell their ecobricks to raise money for community projects.

Noble hopes that the use of ecobricks in a commercial building will set a benchmark for future industry projects in South Africa and around the world.

It is estimated that, in South Africa, 16% of plastic is recycled, 10% ends up in waterways and the ocean, with the remaining 74% ending up in landfill.

The ecobricks element is one sustainability-focused aspect of the 8 500 m2 building. The development also includes a ground-breaking ‘central street’ concept, naturally ventilated with fresh air and breakaway zones. The use of timber for the façade of the commercial building is a first in South Africa. The building features a cross-laminated timber façade that significantly reduces the carbon footprint of the building.

“We have spent a lot of time and energy on the high-performance façade, which keeps the energy in,” says Noble. The façade is designed to facilitate passive climate control inside.

“I think we are at the forefront of development on the continent and are up there with a lot of interesting practices and clients around the world. We have tried to do the responsible thing with everything in this building,” he adds.

The building has been designed in line with Deloitte’s commitment to the United Nations Sustainable Development Goals.

The V&A is jointly owned by Growthpoint Properties and the Government Employees Pension Fund, represented by the Public Investment Corporation.