The spreading trend toward “green” building has resulted in a number of competing and overlapping certification systems, with only faint hope in sight of better standardization. United States builders are most familiar with the LEED system sponsored by the United States Green Building Council (USGBC). Through USGBC’s association with the World Green Building Council, LEED is now available in almost 60 countries, spanning the globe from Malaysia to Morocco.
Starting in 1996, Canada’s Building Research Establishment developed its Environmental Assessment Method. This then evolved into an online assessment and rating tool owned by BOMA Canada, known as Green Globes. BOMA Canada then licensed Green Globes to the Green Building Initiative (GBI) in the United States to compete with LEED. To raise its “market share” GBI has applied to have Green Globes accredited by the American National Standards Institute.
Outside of the Americas, the BREEAM standard promulgated by BRE in the United Kingdom has become widely used and adopted for use in Europe and the Gulf Region, with approximately 110,000 buildings BREEAM certified. There are also a number of national and local standards. France has the HQE system, and about 70% of the commercial buildings built in Australia since 2002 have been rated under the “Green Star” system. In Italy, a regional standard known as Protocollo Itaca was developed for specific regions, but has now been divided into two separate and more streamlined standards.

Most of these standards are privately owned and promoted, but on December 11, 2009 at the Climate Change Summit in Copenhagen, the United Nations Environmental Programme (UNEP) unveiled the “Common Carbon Metric” for measuring energy use and reporting greenhouse gas emissions from building operations. UNEP proposes establishment of the Common Carbon Metric to measure the weight of carbon dioxide equivalent (kgCO2e) emitted per square meter per year by different building types and climate regions. While the Common Carbon Metric has yet to be adopted by any governing body, entities such as BRE and the USGBC may well incorporate the metric in their rating systems.

The diversity in rating systems means that parties wishing to build green projects in diverse locations need to be familiar with different standards for use in different countries, or even regions within a country. The different rating system requirements also need to be compared to local building codes and regulations, to ensure that there are no conflicts between them.

This diversity also undermines one of the principal business reasons for green building. A recent study sponsored by the World Green Building Council determined that the top business reason for green building is because it is the “right thing to do.” Positive publicity is the most obvious commercial benefit from “doing the right thing,” and a common standard for assessing a project’s “greenness” makes garnering that positive publicity much easier. The Sustainable Building Alliance (SBA) is working to solve this problem by developing common minimum standards for adoption by the different rating systems. SBA’s goal is to ensure consistency among the systems and to promote “dual certification.” But because each rating organizations has its own commercial interest in promoting its system, SBA has a difficult task ahead of it. Uniformity is certainly in the interest of engineers, architects, builders, and owner/developers, and there are early signs of progress, as SBA has reportedly fostered an agreement between BRE and HQE to create together a common standard for the European Union.

William Devan
Andrew Ness



  1. You bring up some good points. While I think the Common Carbon Metric is a good idea, it will be important to understand all the various rating systems. Each system claims that it is the best one for promoting the environment and being sustainable. These systems generally differ by a few percentages in different areas, whether it be air quality or water. These systems should work together to make one universal system that combines the advantageous parts of each system. Afterall, it is one environment, one world, one planet. How many different ways can we better it? If everyone is close to being on the same page, they should just work together. It will be way less confusing, and make more sense. Right now it is too much like a competition: our rating system is better and more sustainable than yours! Is that really what we are going for? Maybe in years to come the less popular systems will fade away and we will be reduced to two main systems that may end up working together to be one. We will see!

  2. Thank you Andy and William for an interesting and informative posting. Certainly there is merit in a uniform system for measuring building CO2 emission, such as the Common Carbon Metric, but there is also merit in the maintenance of regional green buildings ratings tools alongside a global system.

    First, the ratings tools (LEED, BREEAM, Estidama, Greenstar) take account of many small factors beyond the ‘big ticket’ issues of energy usage and CO2 emission. For example, the Australian Greenstar tool considers issues such as natural light inside the building and occupant comfort, as well as the building proximity to public transport and availability of push bike parking/storage. Issues of this nature consider the overall environmental sensitivity of the building and its use but also impact upon the appeal of the building to subsequent owners and tenants. Small issues of this nature cannot be captured in a global, uniform system.

    A second main reason supporting the existence of different ratings tools and systems is regionality. The different climatic and environmental issues faced by different regions of the world will affect the relevance of different issues in building design and construction. By way of example, the UAE Green Building Council certification system is based on the LEED tool, but has been adjusted to take account of Middle East conditions by increasing the relevance of water saving features (among other changes). Given different climatic issues and environmental sensitivity, I consider there will always be a need for regional ratings tools. I do agree, however that the existence of multiple systems within the same region will only lead to confusion resulting in a potential reluctance in uptake. In the UAE, Dubai uses the Emirates Green Building Council’s tool whereas Abu Dhabi has the ‘Estidama’ tool. Certainly consolidation within regions will bring efficiency and clarity.

  3. Thanks for the comments! How about reconciling the problem of universal standards vs. regional variations by having a uniform set of core standards that are applicable everywhere, with regional supplements that incorporate additional standards appropriate to that region?

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