Another ‘green’ office building for the Lynnwood Bridge precinct, Tshwane

12 March 2014 - Engineering, management and specialist technical services company Aurecon achieved a first in Tshwane in 2011 when its Lynnwood Bridge Office Park building, situated just off of the N1 highway, achieved a 4 star GreenStar SA – [Office Design v1, Office Design v1] rating from the Green Building Council of Southern Africa.

The company is currently undertaking work on another ‘green’ office building in the same precinct which will comprise five basement levels, as well as ground plus five floors.

The project is being developed by Atterbury, with Studio 3 Architects International (Pty) Ltd as architects, and Aurecon responsible for the majority of engineering design disciplines on the project. “It’s been encouraging to work with a project team who is committed to and sees the value in ‘going green’,” comments Smith. The entire project team has tackled multiple challenges thus far, including an adjacent wetland and the two podiums being rated as a single development, as a team effort. “This kind of collaboration is only possible when a professional team sees the value in pursuing sustainable developments,” explains Aurecon’s national green building expert, Martin Smith.

“A wetland in close proximity to the building threatened registration with GreenStar SA, unless a viable solution to mitigating potentially harmful water run-off, which could negatively affect the surrounding flora and fauna, was found,” explains Environmentally Sustainable Design consultant at Aurecon Marni Punt. Aurecon’s building makes use of various species of plants affixed to the building’s northern car park façade to act as a natural filtration system. “This system, although effective, was a costly solution for these offices,” explains Punt. “This building will make use of a mechanical water filtration system which is more cost-effective and integrated with the building’s other water systems.”

Additional features aimed at achieving maximum sustainability include, amongst others:

• All taps throughout the building will be fitted with flow restrictors so that no water is wasted through unnecessary usage.
• A rainwater harvesting system will collect, store, treat and use large quantities of rain from the roof of the building and surrounding hard surfaces such as paving. This treated water will then be used in applications where potable water is conventionally (and unnecessarily) used, i.e. for flushing toilets. Potable or municipal water will be used in the remainder of applications within the building i.e. bathroom and kitchen taps, change room showers and tea bays.
• Water meters will be installed for all major water uses in the project, as well as an automated effective mechanism for monitoring water consumption data. This Building Management System will mean that water leaks can be detected far more quickly and attended to straightaway.
• Furthermore, each floor fitted with a sprinkler system has isolation valves or shut-off points for floor-by-floor testing (using recycled water). These measures ensure that large quantities of water are not wasted through routine fire system testing.

Smith goes on to say that these offices have been designed to provide a comfortable and stimulating environment for tenants, with indoor environment quality enhanced by the following features:

• The design will aim, and modeling carried out to ensure that 98% of the building’s occupants will feel comfortable and satisfied with the internal building temperature.
• Efforts have been made to ensure that a maximum amount of daylight enters the building. The unwanted effects of daylight glare have been minimised through control measures such as fixed shading devices and blinds on the windows which may be adjusted to shade the working plane from direct sun at desk height.
• The CO2 levels will be carefully monitored and controlled to optimise the indoor air quality, while at the same time conserving energy.
• The HVAC systems will operate on full fresh air when outside conditions are favourable.
• High frequency ballasts will be installed in over 95% of the office Useable Area (UA) to eradicate the flickering effects of fluorescent lighting, which often causes headaches. This will also serve to improve the efficiency of the lighting.
• To limit the amount of Volatile Organic Compounds (VOCs) in the air, interior finishings such as carpets, paints, adhesives and sealants with low VOC emissions will be used.
• Within the general office space, internal noise resulting from the building services and ambient sound levels has been reduced by using materials with a sufficient sound insulation level.
• All composite wood products have low formaldehyde emissions.
• The building includes a dedicated tenant’s exhaust riser system which eliminates harmful pollutants from the printing areas.
• High performance glass will limit the noise from the adjacent highway and ensure maximum thermal comfort.

Punt adds that because the building consists of two towers, many of the tower’s systems could not be fully integrated. “The two towers will be submitted as one development with a single rating, which means both towers are jointly required to achieve a high level of performance.” She explains that this will be achieved through careful modelling of the towers’ performance and constant tweaking of the building systems to achieve desirable performance levels.

After handover, the building owner will implement tuning of all building systems. Monthly monitoring will be undertaken, and the outcomes will reported to the building owner quarterly to allow corrective action to be taken. What’s more, full re-commissioning will be undertaken 12 months after practical completion. These initiatives will ensure that the building systems perform optimally, in the manner in which they were designed.

On the question of whether the investment in green technologies is more costly than a conventional building, Smith believes: “It’s critical to realise that a green building is a long-term investment. Paybacks such as increased productivity and decreased sick rates, although difficult to quantify, also represent significant gains. Both Aurecon’s current offices and this ‘green’ office building in the same precinct demonstrate that it’s possible to deliver a superior, integrated end product that is an asset to the people who use it and the natural landscape which surrounds it.”