Adding to Aurecon’s growing list of environmentally sustainable building projects, Mayfair on the Lake, a multifunctional development on KwaZulu-Natal’s (KZN) prestigious Umhlanga Ridge, has been awarded a four-star Green Star SA Office As Built v1 rating.

Developed by Growthpoint Properties, Mayfair on the Lake is the first office building in the province to have been designed and constructed by a property developer to achieve a four-star rating from the Green Building Council of South Africa (GBCSA) without tenant impetus. It is also only the third building in South Africa to achieve both Office Design v1 and As Built v1 ratings.

Construction of Mayfair on the Lake, a R100-million development, began early in 2011 on the second of three planned phases, with the second phase completed in May 2012. Designed to be a modern interpretation of neighbouring Lincoln on the Lake, the first phase of the development, the L-shaped five-storey office building has a total gross floor area of 6 415 m². The final phase of the development is in conceptual design stage.

“Mayfair on the Lake encapsulates the owner’s commitment to environmental sustainability principles, while delivering efficient usable floor space combined with an economical façade,” explains Candice Manning, Aurecon Environmentally Sustainable Design (ESD) Consultant and winner of the GBCSA’s ‘Rising Green Star Award’ this year.

Aurecon was appointed as ESD consultant as well as the Wet Services engineers and Mechanical engineers on the project – the fifth building project in which Aurecon was involved that achieved a Green Star SA rating.

“Our growing track record in Green Star rated buildings meant that we brought an unparalleled body of knowledge to help achieve the developer’s environmental objectives,” says Manning. “Guiding the professional team to apply optimal attention to each of the nine Green Star SA environmental performance categories is a particularly interesting new dimension to our project involvement.”

Some of the key areas that contributed significant points to a Green Star SA rating were:

Thermally-efficient envelope: a high level of thermal insulation was incorporated in the design of the building envelope and roof. Sun-facing areas of the façade feature overhangs and shading structures to reduce heat gain to the building. Argon gas sealed double-glazed windows with a low shading coefficient enhance the insulation efficiency of the envelope.

“Aurecon’s sophisticated energy modelling confirmed that the building envelope, together with the efficient building services, decreased greenhouse gas emissions by 46% compared to a notional standard building. This assessment is based on the principles in SANS 204, which compares energy efficiency by using the equivalent amount of greenhouse gas emissions as the common denominator,” explains Andrew Wills, Aurecon’s heating, ventilation, and air conditioning (HVAC) engineer for this project.

Keeping cool in KZN: indoor environment quality and energy are the two highest potential point scoring allocations of the Green Star SA rating system and particular attention was paid to optimising the building’s air conditioning.

Wills says: “Energy efficient air-cooled chillers, with future ice storage facilities, mounted at roof level serve air-handling units located in zoned areas on each of the floors. Variable air volume (VAV) systems have been designed with optimally short duct runs to minimise static pressure and reduce fan energy consumption. Variable speed drives on the fan motors further reduce energy usage under part load conditions. Individual control of spaces is achieved with VAV diffusers to ensure optimum thermal comfort to occupants.”

Water saving: the project achieved a high score for its water conservation systems.  Condensate waste water from the air-conditioning system replaces the normal use of potable water for the building’s toilet flushing system. Low water consumption fittings have been used throughout the building, such as dual flush toilets, waterless urinals, high-efficiency showers for cyclists and low-flow efficient taps.

“The cumulative impact of addressing a host of seemingly small water usage elements has been extremely beneficial,” comments Aurecon’s Wet Services Engineer, Ryan Lloyd.

Ultimate goal: Mayfair on the Lake has successfully combined an aesthetically imposing building that is an asset to the urbanisation initiatives in this sought after developing precinct, with the ultimate goal of delivering cost-efficient and environmentally-friendly office space to future tenants.

“The outcome is a credit to the environmentally sensitive long-view taken by the developers, and the commitment to sustainable design and build quality of the entire professional team,” concludes Manning.