For many people, the three leading international systems for certifying sustainable buildings – DGNB, LEED and BREEAM – are sometimes used in the same breath and the public perception is that they’re largely interchangeable. But if you take a closer look at the obvious overlaps between the systems, there are actually a number of fundamental differences. This is what our blog series is about.
The first part of the blog series dealt with some basic differences of the systems. Apart from other differences, there are also a number of overlaps. This shows the second part of the series.
5) The logic behind the awards
There are also differences between certification systems when it comes to the names for different award levels. The DGNB and LEED bestow platinum, gold and silver awards (plus bronze for the DGNB for existing buildings), whereas BREEAM has outstanding, excellent and very good for its top awards. For all approaches, the scores achieved for a development depend on total performance for the different criteria used under each system.
Even if the terms used for the DGNB and LEED systems are based on the same logic, the results achieved through certification are not directly comparable because they are based on different criteria and target values. The DGNB System is considered the most comprehensive method worldwide. Therefore a DGNB certification with an award on the highest level is the best way to document high quality in terms of sustainability. Moreover, the DGNB is the only system to provide a clear overview of achieved certification results by producing diagrams and graphs that can be shared with others.
6) Non-profit vs. private
The DGNB is a registered association (a German ‘e.V.’) and thus a non-profit, non-governmental organisation. It has roughly 1,200 members who are committed to the promotion of sustainable building. This is partly achieved through the work of the DGNB Academy, which offers experts throughout the world training and continuing professional development options in the field of sustainable building. It also promotes sustainable building through its certification system, an important instrument in translating concepts of sustainable building into planning and construction practice. All of the methods anchored within the DGNB System revolve around many years of honorary work and the commitment of hundreds of leading experts involved in all fields of the German construction and real estate industry. It is these experts who ensure that the requirements outlined by different criteria are continually kept in line with latest developments and that they also take any new issues into account, especially if these have the potential to trigger new sustainability approaches. The actual task of certification is carried out by the limited liability company DGNB GmbH, a wholly owned subsidiary of the association.
DGNB graphs provide a clear overview of achieved certification results.
BREEAM was introduced following development work carried out by the British Building Research Establishment (BRE). Its work is implemented by private organisations on a domestic level, both in Germany and other countries, through a licence agreement. The LEED system is offered by the U.S. Green Building Council (USGBC), whose international sales activities are partly coordinated and carried out by national spin-offs of Green Building Certification Inc. (GBCI). GBCI is a for-profit subsidiary of the USGBC, which offers not only LEED certification but also a variety of other certification methods such as WELL, PEER and Parksmart. These were not developed by the USGBC and have not been developed any further; in part they were acquired.
7) Scheme diversity and system variety
All certification systems have one thing in common: they offer a whole host of options when it comes to planning, new buildings, existing buildings, the running of buildings and renovation. They also have different schemes such as offices, industrial buildings and educational buildings. This is important when it comes to using certification as a tangible tool of planning and optimisation because without different options, it would not be possible to apply appropriate criteria or benchmarks to the right projects. Depending on the type of building, different criteria will be looked at, or other indicators will be used as a basis for the individual criteria. The actual number of schemes offered is different for each system. Options and products are also regularly overhauled and updated. For example, the DGNB has had a certificate for buildings in use since 2016. It also offers a new and completely revised system for renovated buildings. On top of this, there are now also new usage profiles for interiors, sports halls, resorts and vertical cities.
One thing that makes the DGNB different is that all the updates and overhauls are, as best as possible, used to harmonise individual system options and make it possible to generate synergies between the different types of certification. For instance, Version 2018 of the new buildings certificate is valid for nine different types of building uses. Coherence between the different systems used for buildings in use, interiors and districts has also been significantly improved. Recently, a new process called DGNB Flex was introduced. This method makes it possible to create an individual certification template for development projects for which no specific scheme yet exists.
8) Time and money
Version 2018 of the DGNB System comprises 37 criteria. This makes the DGNB System significantly leaner than comparable versions of LEED (52 criteria) or BREEAM (57 criteria). It also highlights the underlying aim of the DGNB objectives in only dealing with topics that really help improve the quality of a building. Because international projects involving the DGNB revolve around regional certification requirements, a variety of documentation requirements are not even necessary in some areas; these are sufficiently addressed by the regulatory requirements of individual countries. Overall, the DGNB tries to align processes to documentation that would already be required for the construction process anyway. This is in order to avoid making use of the certification system unnecessarily complicated.
For all systems, the cost of certification is broken down into a fee for consultation, the actual certification fee for conformity checks and, where applicable, any additional costs for simulations, quality evaluations and similar services. The certification fee itself depends on the size of a building and different schemes. A major share of costs relates to the services provided by the individual auditors or assessors, who are required to provide support for the project and the submission of documents and applications. The scale of these fees is entirely individual and based on the extent to which auditors are also asked by building owners to provide advisory services.
Another difference between the systems lies in the training specialists have received. With the LEED system, experts can gain accreditation through self-study. At the DGNB, auditors go through different modules of practical training run by the DGNB Academy. To keep their licences for auditing DGNB projects up to date, they must also take part in regular top-up training.
The third and last part of the series will deal with the features that make the DGNB System special.