Key information about the four main environmental assessment methods for buildings


The BRE Environmental Assessment Method, BREEAM, is a voluntary assessment method used to describe both new and existing buildings’ environmental performance. The method originated in the UK, but buildings built outside the UK can also be assessed using BREEAM: International.

There are standard versions of the assessment for common building uses including: courts, healthcare, industrial, prisons, offices, education, retail and ecohomes. Less common building types can be assessed against tailored criteria under BREEAM: Bespoke.

The assessment works by giving a building a score based on its performance against a series of set criteria. There are two assessment stages: a design stage assessment that leads to a provisional rating followed by a post construction assessment leading to the final rating.

The building’s score will establish its BREEAM rating. BREEAM “Outstanding” is the highest rating, followed by Excellent, Very Good, Good, Pass and Unclassified.

Whatever the rating there are minimum standards the must be achieved across a range of factors including carbon emissions, waste and potable water. Extra credits are awarded for design innovations that will reduce a building’s impact on the environment in an innovative way.

Last updated: August 2008

Revision due: document’s revised on an ongoing basis


Leadership in Energy and Environmental Design (LEED) is a green building certification system developed in the US by the US Green Building Council. It is aimed at improving a building’s environmental performance in areas such as energy savings, water efficiency and CO2 emissions reduction.

Like BREEAM, LEED certification is available for all building types including new construction, existing buildings, commercial interiors, shell and core, schools and homes.

The assessment can be applied throughout a building’s lifecycle from design and construction, to operations and maintenance, tenant fit-out, and even retrofit/refurbishment.

Like BREEAM, LEED is a point based system where building projects earn LEED points for satisfying specific green building criteria. The certification process offers four categories based on the number of points accrued, the highest rating is Platinum, followed by Gold, Silver and finally Certified.

The most common route for a building to be LEED accredited is for a LEED accredited professional to assemble the accreditation documentation. The evidence is then submitted to the USGBC which does the assessment and issues the certificate

The system has since been adopted by 24 other countries including India, Canada and Brazil where it has been modified to suit their particular location and climates.

Last updated: April 2009

Revision due: on going on a document by document basis

Green Star

Launched in 2002, Green Star is a voluntary environmental rating system modelled on BREEAM and developed by the Green Building Council of Australia to be relevant to continent’s particular challenges.

To achieve a Green Star rating a building must achieve a minimum score across nine environmental categories: management, indoor environmental quality, energy, transport, water, materials, land use and ecology, emissions and innovation.

These categories are divided into credits and points are awarded and a score calculated. Unlike other assessment tools, credits are given a weight based on the location of the project to reflect the different needs and ecologies of the States of Australia.

Depending on the number of points a building will be rated: four, five or and six green stars. A six star rating is the highest and signifies “world leadership” in environmental design. A project must be verified by the gbca to qualify for the badge.

Versions of the system are also used in New Zealand and South Africa.

Last updated: 30 April 2010

Revision due: Ongoing revision of documents


Estidama is a sustainable urban planning initiative developed by the Abu Dhabi Urban Planning Council and is based on the four pillars of sustainability: environmental, economic, cultural and social. The initiative includes the Peal building rating system as part of the Estidama integrated design initiative.

The Pearl system is based on both BREAM and LEED, but has been developed to encourage the sustainable design, construction and operation of communities, buildings and villas in Abu Dhabi’s hot and arid climate where temperatures can reach 500C and 100% humidity.

There are three stages of certification: design, construction and operational rating. The first two stages are provisional with a Pearl assessment only being awarded after two years of operational use. (note: The operational assessment system is still to be published).

Design teams must include a Pearl Qualified Professional whose role is to be the point of contact between the design team and the Pearl competent assessor.

Unlike BREAM and LEED, which are voluntary, the Pearl rating system is being incorporated into Abu Dhabi’s building codes so that in the future compliance with Peal could become a mandatory requirement. Currently a building that complies with the building codes will automatically achieve the lowest rating of One Pearl.

Like LEED and BREEAM, Pearl is a points-based system with mandatory components. However, because of Abu Dhabi’s climate, the emphasis of the Pearl rating system is on water conservation rather than energy consumption.

Last updated: April 2010

Revision due: Awaiting publication of the operational assessment document