After a period when each label worked alone, a connection is being at last set up between the main labels. Three initiatives are at the origin of this convergence.

The first meeting was organised by the French Paris-La Défense Business District public establishment, which invited French CSTB and British BRE to examine the possibility of convergence. A European approach was soon highlighted. German new green label organization was contacted. Sustainable Building Alliance (SB Alliance) was created, in June 2008.

SB Alliance’s goal is to develop common metrics that can be used to monitor and compare internationally sustainable performance and ecological behavior. It works to develop a greater level of commonality between the different assessment tools to improve understanding, comparability and take-up.

SB Alliance is a non-profit coalition of standard setting organizations, national building research centers, and property industry and construction sector stakeholders that is intended to accelerate the international adoption of Sustainable Building (SB) practices through the promotion of shared methods of building performance assessment and rating.

 Its Core Group reunites BRE (United Kingdom), CSTB (France), DGNB (Germany), FACV (Brazil), ITC-CNR (Italy), NIST (USA) and VTT (Finland). Then IVE (Spain) and, in October 2009, USGBC, which runs LEED, joined the Core Group. At the beginning of 2010, the Japanese GBC, which runs CASBEE, joined SB Alliance.

SB Alliance is co-chaired by Carole Le Gall, Managing Director of CSTB and Carol Atkinson, Managing Director of BRE-Global.

In June 2009, BRE and CSTB signed an agreement to elaborate together a European environmental label for buildings.

In March 2009, an agreement, with roughly the same aim, was signed by Green Building Councils from the US (USGBC), Australia (GBCA, which runs Green Star), the UK (UKGBC) and BRE.

Then the two initiatives converged through an agreement between SB Alliance, the World Green Building Council (WGBC), CSTB, BRE, DGNB, GBCA, UKGBC and USGBC. Six essential indicators are suggested: carbon, energy, water, waste, indoor quality and profitability.

The third initiative was taken in 2008 by UNEP Sustainable Buildings and Climate Initative (UNEP-SBCI) which set up an international think tank to define and promote a common carbon index.

The different initiatives converged in the meetings organized by UNEP SBCI in Paris and Singapore in September and October 2009, and the presentation of a common framework, at a meeting held by UNEP-SBCI, at the Copenhagen Conference on Climate Change, in December 2009.

The Stephane Pouffary and Niclas Svenningsen presentation summed up the “Common Carbon Metric Report for Measuring Energy Use & Reporting Greenhouse Gas Emissions from Building Operations”.

A common framework is proposed for the first two indicators, among the six indicators suggested by SB Alliance. Energy consumption and CO2 emissions will concern, for the moment, the use of the building. The data will be Measurable, Reportable and Verifiable (MVR). They will be gathered according to the principles and methods of international standards (ISO among others).

Four indicators are proposed: KWh/m²/year and if possible KWh/occupant/year, kg CO2 equivalent/m²/year and kg CO2 equivalent /occupant/year.

The framework has to be transformed into a practical tool after a major consultation of Construction and Property Sector actors. Then the method will concern the other indicators specified by SB Alliance.

The aim is not to elaborate one worldwide environmental label but to define and implement a common methodological framework for the main international labels. It is a progress which was awaited with some impatience by international public authorities and investors.