In terms of mandates, the one for the new Vangate Shared Services Centre Building in Athlone was bold and unambiguous: an iconic green building that addresses the social and economic needs of the surrounding communities. It was also the Western Cape provincial government’s first attempt at green building.
The R160 million Vangate Shared Services Centre Building (VSSC) completed in late 2010, employed environmentally friendly design strategies and technologies such as passive solar light shelves, screens and solar chimneys which assist with hybrid passive ventilation and an energy efficient HVAC system. It claims to be 60% more efficient than the standard systems and the highest efficiency of this type of building in the country to date. The building is water self-sufficient and materials used are predominantly local, non-toxic and from renewable sources, while the embodied energy of each material was considered in order to minimise impact. The construction process also followed some clear empowerment targets.
However despite the commendable intentions, according to David Aitchison, acting senior manager of Provincial Public Works General Buildings, changed requirements from the end user, as well as having to attend to various latent defects, there has been no follow-up data study as yet.
Architect Pieter Swanepoel, from the Western Cape Department of Transport and Public Works who is currently overseeing the VSSC progress, elaborates and states that some additions and reconfigurations are taking place to meet the requirements of new tenants who were not part of the initial design process. The building is currently not fully occupied and various latent defects and maintenance issues are still being addressed. Accurate data testing and analysis will be considered in the future, once completion of the building has been certified.
Thembi Jacobs, director of TMTJ Cape and project manager of the VSSC building, adds; “There are no defects related to the original design. We have had to change the layouts to accommodate the tenants of the building, which in turn has obviously impacted on the service layouts. None of the changes have in any way affected the green benchmarks the building design has set itself. The defects currently noticeable are being dealt with. Furthermore, there are a few issues continuously coming up that are maintenance related, and these are also being dealt with by the client.”
James Wei, mechanical engineer at WSP Consulting Engineers SA (Pty) Ltd, explains; “with a large portion of the heat load attributed to computers and people, recording energy consumption would be fruitless unless the building is under normal use and fully occupied. The data collection is also best done over a long period, which includes hot summer conditions and cold winter conditions.”
Ryan Visser, mechanical engineer, also from WSP, adds that “although the HVAC system was designed and installed to be able to operate as efficiently as possible, it is not possible to monitor the exact efficiency of the system, as no power monitoring systems were installed to record its energy consumption although it was something that was looked at. Also, the HVAC system will only be effective if operated correctly which it currently isn’t and is not performing at its optimum potential as a result. Many of its features are not being utilised and the control system has not been adjusted to suit the final tenant requirements.”
According to Peter Geddes, mechanical engineer of Provincial Public Works General Buildings, who was brought in to attend to user concerns of poor air circulation and heat, the HVAC system appears as if it has never been properly commissioned. The maintenance contractors are currently engaged in restoring the system to operate at its full design capacity, only after which fine-tuning of the controls can be done with the aim to realise the energy-saving potential of the design.
Conflicting feedback was received about the effectiveness of the grey water system, which was designed for toilet flushing purposes (with the municipal water system as back-up). Closer investigation indicated that it has never been operational.
Shaun Pietersen, director of Ubunye Engineering Services (Pty) Ltd., the plumbing and drainage consultants for the VSSC project, confirms: “The grey water system has never been a problem for flushing as it’s never been used.” This was mainly due to the building being partially occupied. The pumps were vandalised and clogged due to non-circulation. “The large amount of bacteria found after taking a water sample required the entire system to be flushed, then refilled with municipal water and then re-activating the grey water system in order for the system to work to its full capacity. We are currently waiting on the go-ahead for reinstating the system,” says Pietersen.
On a positive note, Riaan Steenkamp of MDL Architects reports that the performance of VOC-free paints in terms of durability and fading has been equivalent to any of the superior paints on the market containing toxic chemical compounds and the addition of fly-ash content in the concrete has also been successful. No defects such as cracks have been observed.
It appears that due to the VSSC being a technologically advanced building, appropriate post-development training skills are required in combination with constant management and proper building maintenance systems to deal with the sophisticated requirements.
The new completion date is now March 2012. This building remains a flagship for bold vision and lessons learnt the hard way.
Read the full feature in the April-May 2011 issue on p48.