The new No 1 Silo office building at Cape Town’s Victoria & Alfred (V&A) Waterfront has been awarded a six-star Green Star SA rating by the Green Building Council of South Africa (GBCSA).

The Green Star SA rating system was established by the GBCSA in 2008 with the aim of evaluating the potential environmental performance of buildings.

The No 1 Silo office development is South Africa’s largest green office building, the second building to be awarded a six-star green rating in the country and the first in the Western Cape.

“We have adopted a rigorous approach to green construction and sustainable design principles, and the efficient use of natural and energy resources,” V&A Waterfront CEO David Green says.

The No 1 Silo development is currently under construction and due for completion in June. Among its environment-friendly features is the use of seawater from the Atlantic Ocean, to reject waste heat from the cooling plant, resulting in significant potable water savings, while improving overall energy efficiency.

To further save drinkable water, a grey water system has been installed, which will collect and treat wastewater from hand washbasins and showers to be reused in the toilets.

Another key innovation of the building is the double-glazed, double-skin and high- performance façade that reduces solar heat gain, while maximising the natural light penetration into the building.

The underfloor mechanical air-conditioning system supplies cool, fresh air from the raised floor, which then absorbs warmth as it rises and is extracted at ceiling level, thereby effec- tively preventing the build-up of pollutants.

To add to its energy-saving abilities, No 1 Silo has been equipped with an efficient and environment-friendly lighting system, with highly efficient fittings having been selected. In addition, an intelligent individual addressable lighting system, fitted with appropriate sensors, will ensure lights are on only when needed.

The building is being constructed using 60% less concrete than its conventional counterparts and Forest Stewardship Council-certified timber is being used, which has been procured from environmentally sustainable and ethical sources.

Further, more than 70% of all waste generated on site will be recycled.

Meanwhile, the V&A Waterfront was upgraded to a gold-level recipient of the global eco-labelling and rating system, the Heritage Environmental Rating Programme, in Decem- ber. This followed the waterfront’s 2012 Eskom eta Award for energy efficiency in the com-mercial category, as well as the 2012 Energy Efficiency Forum Awards for commercial buildings in November.