The previous part of the “Serious about Green Roofs” series investigated four international green roof case studies. I identified four key lessons that we can learn from these cases to help with creating our own green roof industry. Now we can take a look at two national case studies as a comparison. The only incentive towards green roofs in South Africa is a sustainability rating tool called the Green Building Council’s Green Star SA Credits. This voluntary system was inspired by the 2002 Australian Green Star tool and has been in effect since 2007. The tool awards up to one hundred credits to a development based on specific sustainability criteria. A green roof has the potential to earn twenty four of these credits. Compared to other international sustainability rating tools the Green Star SA Credits is the least effective in incentivising a high level of sustainability. Even with the lack of policies and incentives the following case studies will show the various potentials for the introduction of a green roof industry.
Cape Town, South Africa:
Cape Town’s Management of Urban Stormwater Impacts Policy (2009) mentions Water Sensitive Urban Design (WSUD) which provides an opportunity for green roofs to be absorbed into the policy. The policy defines this type of design as practises that encourage biodiversity, amenity and aesthetics. Furthermore it is stated that the City may introduce incentives to encourage these types of design. The City has also published a Cape Town Smart Building Handbook (2012) within which a pilot garden roof developed on a city building features as an example. Other than these documents there are a few other projects in the area that show support for green roofs. These include two intensive garden roofs implemented on City owned buildings in 2000 and 2006. Another innovative project includes the implementation of green walls within informal settlements to promote a greater quality of living for the lower income residents of the city.
Durban, South Africa:
Durban seems to be miles ahead of Cape Town at this stage. Since 2006 the City has been running a Municipal Climate Protection Programme. The programme entails a series of phases including extensive local research and plan formulation. During 2008 the Green Roof Pilot Project was launched as part of this programme. Eight green roofs were constructed on a City building each featuring different plants, growing mediums and green roof techniques. Within the same year green roofs where also included within the Municipal Adaptation Plans as effective stormwater management techniques. The pilot project led to the creation of the Guideline for Green Roof Habitats in 2010. This was a very important contribution as residents within the area had already started to implement their own green roofs. These guidelines assist with the different substrate, plant and maintenance options specific to the Durban area. Another project within the area worth mentioning was a high school green roof that was part of the Creating Learning Space Programme. Here green roofs where implemented on various school buildings as well as on the covered walkways. The plants used in the project could all be found within a 50km radius of the school. International scholars have noted that this project currently has one of the greatest varieties of plant species recorded on a green roof. Looking at these cases it becomes apparent that South Africa still has a very long way to go. Especially Cape Town when compared to Durban. The key lessons identified in the previous part of the series can help us in establishing the areas we have to work on.
- Research: In this aspect Durban has the upper hand. If the time that it took Linz to get a system in place has to be taken as a benchmark South African cities will only start to effectively implement green roof strategies in about 10 years. This is, if they have already started to do some form of research on the topic.
- Motive: Durban has already launched a dedicated research project regarding the concept of green roofs. They have also chosen a direction through which to promote green roof uptake in relation to climate change mitigation. Other localities should also look at their own individual issues and determine where green roofs can be used to mitigate these.
- Support: In both Durban and Cape Town the City has already expressed their interest in the technology by constructing green roofs or garden roofs on their buildings. It is important for the government to lead by example.
- Variety: As far as policies and incentives go there are virtually none of these available in a South African context. As mentioned previously, the only real incentive is the SA Green Building Star Credits which is at this stage only a voluntary system. However, gaps within existing policies could be used to tie in green roofs in an effortless manner. The main problem to solve in this regard is with what policy or incentive we need to start.
Also see Green Roofs: International Inspirations + Green Roofs: Local Realities Booysen, K. 2013. Aspects that encourage the successful integration of Green Roofs in cities: Policy Issues and Green Roof Specialist Perceptions, Dissertation submitted in partial fulfilment of the requirements of the Degree in Master of Philosophy in Urban Infrastructure Management and Design, Department of Engineering and Built Environment, University of Cape Town. Cape Town Green Roofs: Garden & I Landscape SA Durban Green Roofs: Green Roof Designs