The Western Cape Government Department of Health’s new day clinic in Beaufort West – Hillside Clinic – was recently awarded the AfriSam-SAIA Sustainable Design Award for its innovative and sustainable design considerations implemented in close collaboration with recognised local architectural firm, Gabriel Fagan Architects.
During our exclusive interview with John Wilson-Harris, director at Gabriel Fagan Architects, he explained how they overcame common sustainability challenges within a limited budget to bring a new dimension to approaching local architectural challenges by giving special consideration to the building’s context.
Concept building designs
John explains that they approached Greenplan, a local company specialising in services enabling sustainable energy solutions, solar loads and thermal comfort. Greenplan provided specific calculated verification of general passive building design concepts. They investigated two concept building types, with the main difference between the two designs being the orientation of sub-waiting areas, which are also used as circulation routes.
The importance of context and its environment
“Our core intension was to design Hillside Clinic at a similar cost to other clinics with a reduced environmental footprint, both during construction and operation, which is why we are extremely pleased that our efforts to use rammed earth for the walls and rock stores for thermal tempering of fresh air supply have been both recognised and supported by our peers as well as the Western Cape’s Department of Health,” he comments.
John explains, “As with all sustainability projects, which should in fact be all projects, the key focus areas should be the building’s orientation, and its context and environment, and how these can contribute to green principles and passive design.”
Therefore, the first step was to analyse the local environment, which is Beaufort West, situated in the northern part of the Western Cape province and is the largest town in the arid Great Karoo region. Understanding the climactic conditions and how to optimise the building’s functionality within these parameters were major considerations.
The architecture relates to the urban-domestic context creating an invitingly scaled building that welcomes the community whilst being a beacon of hope.
Extreme weather considerations
The area experiences extremely high levels of solar radiation with relatively low cloud cover. With peak summer temperatures exceeding 40°C and mid-winter temperatures sometimes falling well below freezing point, adequate thermal comfort was essential.
Considering these rather extreme weather conditions combined with limited control of indoor temperatures by mechanical means, the architects were concerned about thermal comfort in the building, especially in the waiting areas which required large amounts of air changes per hour and where air conditioning is generally not included in Government clinics.
Thermal comfort criteria
Greenplan analysed the thermal comfort in the passages and waiting areas using the adaptive comfort model for naturally ventilated spaces from ASHRAE Standard 55.
The data for the alternative design was obtained by performing multiple simulation runs for both different roof overhangs and different orientations, comparing periods predicted to be too cold with periods predicted to be too hot.
In the original design, the waiting areas were located on the south side to be cool during the hot days, but the simulation showed that they would in fact be too cool and that a north orientation would provide better spread of acceptable temperature range. The overhangs were then modelled to achieve best protection from direct sun penetration during summer and for allowing the best penetration of warming sun during winter.
Rammed earth: using local resources
Gabriel Fagan Architects did extensive soil analysis using Outeniqua Laboratories for the technical analysis of possible soil sources, as well as employing simple methods of analysis to establish structural qualities of the available soils. It was found that the soil sourced from the nearby empty Beaufort West dam could be used as the base material for the rammed earth walls, creating an explorative building system for this type of architecture. The system is also labour intensive which assisted with job creation, and those working on the project learnt a new construction technique.
New thinking: rock store for ventilation
John also noted that the area’s rock formations were an ideal fit for introducing the cost effective and alternative rock-store system for the building’s airflow management.
This system uses naturally occurring rocks from the area, ideally shaped in a circular form (roughly the size of a baby’s head) with the right density and interior composition, which then facilitates effective airflow and distribution. The high daytime air temperature is tempered by the cool rocks as the air passes through them. As the rocks relinquish their “coolth” they gradually heat up through the day. During the night the cold night air cools them down again, making them ready for the next day’s cycle of air cooling. In winter the fan is turned off during the night so that the warmth stored in the rocks from the previous afternoon is available to temper the extremely cold early morning temperatures. Electricity used to run the fans is a fraction of the amount used for air-conditioning.
Material and design modularity
In terms of to what extent the knowledge gained from this clinic could be replicated in other projects, John notes, “Modularity is feasible where the climate and environments are the same, typically in UK, but in SA we have considerable climactic differences in our respective provinces, calling for a tailored and contextual approach to these projects.”
Although circulation and spatial relationships between parts of a clinic will remain similar, Cookie-cutter clinic design will not necessarily be feasible for our local healthcare industry given each facility’s area of specialisation and service offering, and the different contexts in which they are placed.
However, the Department has vast insight from working on a range of projects with various architects and have hands-on knowledge on what works best in which environment. This means that modularity or cookie-cutter solutions can apply to layouts of individual spaces such as consulting rooms and treatment rooms.
Champions for change
John says that the Department of Public Works must receive recognition for their willingness to champion the experimental use of sustainable construction methods such as rammed earth and rock-stores as materials of choice for this project. “The Department know what works in their healthcare facilities. From their experience, they have very clear feedback as to what materials they prefer to use, so this diversion from type has been brave of them” John says and adds, “We are very keen to see how they will use the good lessons learnt from this clinic.”
Other material and design aspects:
Other sustainability focus areas of the building include the following:
• Changing the orientation of the waiting areas and patient rooms.
• Overhang, glazed walkways that stop direct sunlight in summer and help to create a warmer hospital in winter.
• Construction – the use of SA Pine, a material that is readily available and regrown. Hardwood was only used sparingly on the outside of the building as beading to the walkway windows.
• Rammed earth for walling.
• Rock stores for a low-cost alternative to airflow management.
• Porcelain tiles because of their antibacterial resistance and durability.
“The department and architects closely consulted with the community to employ local labour and listened to their needs. By doing so we hope that we were able to collectively deliver a building that acts as a centre for dignity and change on socio-economic levels,” concludes John.
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