Is green building really solving problems of sustainability, or is it just a bunch of overly complex rating systems used on a small percentage of projects?
First, it is important to define what constitutes a green building? The US EPA says “green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment by:
- Efficiently using energy, water, and other resources
- Protecting occupant health and improving employee productivity
- Reducing waste, pollution and environment degradation”
The Green Building Council of Australia notes that “Our built environment is currently the world's single largest contributor to greenhouse gas emissions, and also consumes around a third of our water and generates 40 per cent of our waste.”
According to the Department of Environment, “Almost a quarter (23%) of Australia’s total GHG emissions are the result of the energy demand from the building sector.”
The built environment has some room for improvement in sustainability, and green building rating tools have delivered substantial improvements.
Green Star has certified more than 640 buildings since launching in 2003. A 2013 report by the Green Building Council of Australia, The Value of Green Star - A Decade of Environmental Benefits, offers some examples of the efficacy of green building and the Green Star program.
- On average, Green Star certified buildings produce 62 per cent fewer greenhouse gas emissions than average Australian buildings, and 45 per cent fewer greenhouse gas emissions than if they had been built to meet minimum industry requirements.
- On average, Green Star certified buildings use 66 per cent less electricity than average Australian buildings, and 50 per cent less electricity than if they had been built to meet minimum industry requirements.
- On average, Green Star buildings use 51 per cent less potable water than average buildings.
Green buildings cost less to operate and have a smaller carbon footprint, according to the US General Services Administration, which examined 22 green federal buildings and determined that they:
- Cost 19 per cent less to maintain
- Use 25 per cent less energy and water
- Emit 36 per cent fewer carbon dioxide emissions
- Have a 27 per cent higher rate of occupant satisfaction
However, the examples cited apply only to commercial buildings. Housing is a huge factor in the overall footprint of the built environment, and housing construction in most of the world is predicted to grow substantially. Global Construction 2025, a study of the global construction industry published by Global Construction Perspectives and Oxford Economics, estimates "that 270 million new homes will be needed in China and India alone by 2025 to meet the needs of population growth and urbanisation trends. The majority is likely to be affordable housing.”
As for the US, “We forecast the volume of construction output in the US to grow by over 75 per cent between 2012 and 2025. We estimate the US needs almost 20 million new homes by 2025, an average of 1.5 million new homes that need to be built each year.”
A variety of rating tools are in use that aim to improve the sustainability performance of the built environment, and they’ve clearly had a positive effect on the built environment. Unfortunately, they’re used on a small fraction of structures built each year. Green Star, NABERS, LEED, Green Globes, BASIX, BREEAM, NatHERS, Energy Star, and Passive House all approach the problem in somewhat different ways, and with differing impact so far.
BREEAM counts 425,000 certified buildings, and two million registered for assessment since its launch in 1990. The US Green Building Council, administrator for LEED, claims that “There are currently more than 69,000 LEED building projects located in over 150 countries and territories (as of January 2015).”
The Passive House standard, one of the simplest yet most rigorous, counts more than 3,100 certified buildings to date; welcome news, but a minuscule number.
BREEAM and LEED both have certified tens of thousands of buildings, but a massive increase is needed. Housing starts in the US, for example, are in the 900,000 to 1 million range annually. Certifying only 10 per cent of those projects would substantially affect the built environment.
While the rating tools can show some success, critics charge them with excessive cost and complexity, which is especially challenging in the developing world. Some builders say LEED adds $5,000 or more to the cost of a house. For larger projects, it’s much more.
Would it be possible, however, to reap some benefits without the full cost of the rating system? The Town of Hampstead, Maryland, faced a worsening water crisis in 2008. A multi-pronged solution included steps such as aggressively finding and fixing leaks, encouraging more sustainable design and construction methods, and encouraging developers to minimize impervious surfaces.
The town also adopted the LEED Silver certification into the building code, and the WEp1 requirement that all projects reduce water use by at least 20 per cent. Merging rigorous green building standards into building codes offers the potential for mass improvement of the built environment.
In fact, that’s starting to happen. The International Code Council (ICC), ASHRAE, the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES) and the U.S. Green Building Council (USGBC) have announced their intent to collaborate on the development of Standard 189.1, the International Green Construction Code(IgCC), and the LEED green building program. According to the groups’ announcement, they aim to “create a comprehensive framework for jurisdictions looking to implement and adopt green building regulations and codes and/or provide incentives for voluntary leadership programs such as LEED.”
By improving building codes, more professionals will become versed in best practices of green building, leading to greater efficiency, and because the code is the worst acceptable approach, the baseline will improve.
That sounds reasonable, but does this approach offer the potential to greatly increase the market penetration of green building best practices and do so at an acceptable cost?