Environmental sustainability measured with the most widespread rating systems
9 Nov, 2021
One is American, the other English, but both are voluntary systems for the assessment and certification of building sustainability.
LEED and BREEAM use a qualitative approach, whereby the level of sustainability is determined by the sum of points assigned to predefined requirements, referring to specific environmental aspects.
Green building assessment systems
The purpose of a green building is to ensure living comfort for the occupants, while minimising the use of resources and environmental impacts in general.
In construction, the principles of sustainability must take into account three main aspects: the environmental, economic and social aspects.
From an environmental point of view, it is necessary to assess the impact of the construction activity, the use of the building, the employed materials and resources, both locally and globally.
From an economic point of view, the long-term costs and benefits of the operations and materials relative to construction must be considered, as well as those resulting from the use of the building itself.
The social aspect is focused on the end user, considered not only as an individual, but as a community. In addition to living comfort, which must be guaranteed to those who use the building, it is also necessary to assess the impact that the property has on the social context.
The numerous certification systems that have spread in recent years are like a lens on these issues and the desire to find an objective method to assess if and to what extent the performance and functionality of buildings are achieved with the minimum negative environmental impact.
LEED and BREEAM protocols
Since environmental assessment methods have started to spread, there has also been a need for comparable standards.
This has led some systems to expand abroad and become internationally recognised reference points In this sense, the most successful are BREEAM and LEED.
LEED, Leadership in Energy and Environmental Design, was developed by the US Green Building Council and is globally accepted as the benchmark for green building practices.
BREEAM, standing for Building Research Establishment and Environmental Assessment Method, is a building design standard created by BRE Group. The UK government adopts it as a reference for assessing the environmental impact of buildings.
Both are structured in credit-based classification systems and apply to a wide range of buildings, both new and existing.
The addressed environmental issues range from materials to energy, from water to pollution, without leaving out environmental quality and site management
However, the two protocols differ in assessment method, scope and criteria.
Comparison between LEED and BREEAM
LEED and BREEAM share a similar basis. In fact, the US certification program was developed with BREEAMas the reference model.
Both tools give the building a score, which translates into obtaining a certification class.
With LEED there are four levels of building assessment:
BREEAM is the environmental classification that includes:
- Very Good
It is natural to wonder whether the scores of the two systems are in some way comparable or whether the methods used for assessment are superimposable.
The most useful comparison is based on the contents. Despite the same subdivision into categories, the number of areas subject to assessment and the criteria to be met is different, but, above all, the weight assigned to each credit differs.
LEED proposes the following assessment categories:
Localisation and transport
Sustainability of the site
Energy and atmosphere
Materials and resources
Indoor environment quality
For BREEAM the categories considered for the assignment of the score are:
Health and wellbeing
Use of the soil and ecology
The individual items taken into consideration are not all comparable, nor the assignment of the score Accordingly it is very difficult to make an objective comparison.
Similarities and differences reflect the cultural, legislative and economic contexts in which the two rating systems were developed. In terms of process, LEED has a performance-based approach and focuses on the measurement of the results, as is typical of the American mindset, while BREEAM favours a more regulated path.
The merit of both is that they provide concrete support for the design, construction and management of buildings.
In fact both systems take into account aspects relating to the entire life cycle of the building, aiming to optimise processes, reduce management costs and ensure high indoor comfort conditions.
Due to the differences between the two rating systems, it is important to identify from the outset which certification is best suited to the project, in order to fulfil the requirements at the lowest possible cost.
Isopan's LEAF technology helps in obtaining credits for LEED and BREEAM certifications to create high-value projects in the field of sustainability and attention to the environment, and is the first in Europe to have the Declare label.
Marta Lupi, materials engineer and R&D Project Manager at Isopan, is involved in research projects aimed at identifying new product and process solutions. She works closely with universities, research centres and strategic partners for innovation.