The many facets and opportunities of green building design, and the latest rating tool updates.
Green building is underpinned by the seriousness of the state of the planet and the need to provide healthy, comfortable work environments for people. Buildings are long term investments and are around for many years thus it makes sense to make them efficient and happy place to inhabit, says Brian Wilkinson CEO, Green Building Council of South Africa (GBCSA).
“Every individual green building is complex and unique with many different opportunities and challenges that are explored by developers and owners along with their professional teams. Each one is essentially a response to the site, context, brief and budget, with the overall aim of creating a well-designed space for the user.”
When talking about sustainability, most people default to energy-efficiency, but green building spans to include water-efficiency, resource and material efficiency, waste management and alternative transport measures. There are so many facets of green design that offer a plethora of challenges, possibilities and opportunities.
Indoor environmental quality
Creating optimal indoor environmental quality is key to designing a healthy building and involves introducing more daylight and ample fresh air into a space. This needs to be balanced with efficient and well designed HVAC systems in order to not increase energy consumption but the benefits show increased productivity of people as well as less staff sick days, comments Simon Berry, commercial director, WSP Consulting Engineers.
Research conducted by Professor Vivian Loftness, internationally renowned researcher focused on environmental design and the integration of advanced building systems for health and productivity, incorporated global studies that showed:
• An increase of daylight and access to natural views in hospitals can reduce the average length of stay among patients.
• Increased outside air in schools and homes reduces the prevalence of asthma and allergies among children.
• Natural ventilation in workplaces can reduce the risk of exposure to colds and absence due to illness.
• Workers who can control their own task and ambient lighting are more productive and have less headaches.
• Employees with seated access to views of outside vegetation are more productive than those with no view of the outdoors.
“The difficult part is to quantify these savings,” notes Berry. “Whereas you can measure something such as electricity savings very accurately, it is much more difficult to measure staff’s productivity in a green building and compare it to a normal building. Clients are willing to invest in something where they can see the monetary returns, but if you can’t show the exact benefit it creates a bit of a tangent,” he explains.
Passive design elements
“By far the easiest win on any building is just to get the shape, orientation and fixed shadings right. There is something amazing in using interesting passive elements in the building design,” notes Berry.
“Part of the problem with our industry is that we’ve had cheap electricity for too long. Prior to the 1950s, buildings were intrinsically well-designed with, for example, thick walls, lots of shades and verandas in hot climates to keep buildings cool. Once cheap electricity and the air conditioning unit came along, it became very easy to use air-conditioning to overcome bad designs. So the architectural and engineering professions have lost some of that original skill in the passive designs of buildings, something that is coming back into fashion now thanks to the focus on sustainability,” he says.
New double-skin facades
The 30 000m² 90 Grayston Drive project in Sandton, developed by Redefine and due to be completed later this year, will be one of the first commercial buildings that will exhibit a double-skin facade.
It is designed by GLH Architects, together with WSP Green by Design, both companies whom also conceptualised the five-star Green Star SA-rated Standard Bank development in Rosebank and the six-star rated Vodacom Innovation Centre.
Berry explains that by adding an additional skin, a cavity is created with vents at the top and bottom so that the space between the two panes absorbs the solar gains, the hot air rises and escapes at the top instead of heating up the building, while cool air flows in from the bottom. The gap is about 600mm wide, so one can easily walk in there to maintain it. In addition, blinds can also be installed in the cavity rather than on the inside of the building, which will block the sun before the heat can enter the building.
International green building consultant, Jerry Yudelson, calls green building “the tsunami of the future that will inundate the entire real estate industry”.
In his trend forecast for 2014, posted on energydigital.com, he predicts an increasing role of building automation for energy-efficiency using cloud-based systems. He expects that many building owners and developers might even take it a step further to design and operate zero-net-energy buildings in order to distinguish themselves in this area.
Some of his other predictions include that the focus of the green building industry will continue to switch from new buildings to greening existing ones, and that green building performance and product disclosure declarations, along with various “red lists” of chemicals of concern, will become increasingly contentious. He also expects solar power use to grow and an increased awareness of the looming crises in fresh water supply, as climate change affects rainfall and water supply systems worldwide.
Wilkinson points out that in order to maintain the leading edge of building design, there are a few things that the GBCSA sees as becoming more and more important.
Firstly, good design is imperative. “The most sustainable buildings are the most loved and most used buildings. Green buildings need to be both good-looking and perform efficiently,” he says.
Secondly, the better and more integrative the design process both between the professional team members and the team and the client, the better the building.
Thirdly, at a building scale it is imperative to maximise the use of energy and thermal computer modelling tools to test design principals before they are actually implemented. Cutting-edge glass facades, including photovoltaic integrated facades, building integrated renewable energy systems and water filtration systems, as well as innovative ways of cooling and heating, are some of the design elements becoming more established.
Hugh Fraser of Paragon Architects agrees that climate modulating elements inform the design of a building and says that architects should design buildings that look like they work, not just some arbitrary diagram.
Fraser recommends that improving public transport and alternative transport systems, such as cycling, will have a profound impact on where and how we live, including city densities. “It will make the urban fabric more dense and enjoyable and will make cities more walkable,” he says.
Improving insulation on both new and existing buildings, using water tanks, solar power water heating and changing attitudes to water use, are other key factors he highlights. “We need to make long-term comprehensive and thorough decisions that affect buildings and the way we inhabit them,” Fraser emphasises.
Full thanks and acknowledgement are given to the GBCSA, WSP, Paragon and www.energydigital.com for the information given to write this article.
Rating tools update
2014 will see the GBCSA introducing a new Energy & Water Benchmarking Tool for certification, as well as three rating tools becoming available for certification in v1.
The new Energy & Water Benchmarking Tool will enable office building owners to benchmark their performance for energy and water against industry norms, and will help to inform an action plan for building owners to getting a Green Star SA – Existing Building Performance rating.
After having launched the Green Star SA – Existing Building Performance Tool (pilot) in October last year, the GBCSA has received an overwhelming amount of applications for the pilot project programme, which will see over 50 buildings testing the waters. From this process the GBCSA will make final improvements and ensure market applicability before its release in Version 1 later this year. This tool is aimed at existing buildings in operation and will assess the performance, operations and maintenance of a building over a 12-month period.
The Green Star SA – Interiors Tool (pilot) was created to rate interior spaces that are occupied by tenants, and what the tenant has control over, even in multi-tenanted buildings where the base building has not been rated. Several tenants have registered to run the interiors pilot tool for the fit-outs of their spaces and the GBCSA plans to release the tool in Version 1 later this year, after the trial period is complete. The GBCSA expects demand for this tool to come mostly from the retail and corporate office and banking sector, but has seen some interest from the hospitality sector too.
The pilot programme for the socio-economic category is also currently running, in which projects are testing this new category of the Green Star SA rating tool. This optional category assesses the socio-economic sustainability opportunities that exist in the design and construction of buildings.