Building certifications

In 1988, professors Bo Adamson of Lund University, Sweden, and Wolfgang Feist of the Institute for Housing and the Environment in Germany joined forces to define a new type of home based on high energy-efficiency standards. Two years later, the first Passivhaus building was certified—a home that not only used bioclimatic design to reduce energy consumption, but also featured high standards of insulation, airtightness, and indoor temperature control. Based on these standards, this group of professors established the Passivhaus Institute.

Passivhaus was one of many initiatives that emerged worldwide in the late 1980s and early 1990s with the aim of beginning an assessment of the quality of the built environment in terms of sustainability, efficiency, and wellbeing, given growing concern about issues such as climate change, pollution, and the depletion of the planet’s resources.

Private building certifications emerged long before the first state regulations on energy efficiency began to be drafted—regulations that arrived 20 or 30 years later and that, even today, still do not include many essential criteria that are already covered by most private certifications, especially regarding the impact of the built environment on the planet’s sustainability and people’s wellbeing.

The latest mandatory European regulations, which each country has developed based on its own criteria, mainly set requirements in terms of energy efficiency. In Europe, the construction of so-called NZEB buildings—Nearly Zero Energy Buildings—is mandatory from 2018 for public buildings and from 2020 for private buildings. [1]

However, in the vast majority of cases, building regulations do not take into account ecological, social, or health impact criteria that have been included for years in the main private certifications and that make up the so-called NZIB buildings—Zero Impact Buildings.

After more than 40 years of development, certifications have become an essential resource for ensuring the technical quality of a building and its minimal impact on the environment and people. Building certifications are not only a guarantee that many developers or institutions require from architects and builders; in some countries, they are also being introduced as a requirement to obtain building permits.

Andorra, for example, made the private Passivhaus certification mandatory in 2020 for all new-build projects, and in the United States many firms require LEED certification from their architects in order to be hired. These are just a few examples of cases in which having a private certification has been established as a mandatory requirement.

A study focused on unifying and standardising certifications

In response to this issue, in 2014 the European Union developed a study aimed at finding a single building certification system that could be established as a guide for non-residential and publicly promoted developments. The study was carried out by the consultancy Triple and is titled Market study for a voluntary common European Union certification scheme for the energy performance of non-residential buildings. [2]

The document aims to implement a single certification for the European Union, as well as to identify options for improving and standardising energy performance certificates in terms of coherence, reliability, usefulness, ease of access, and accuracy.

The study in detail

The document ranks the 22 leading certifications worldwide and follows a classification scheme in three groups: High market success, Medium market success, and Low market success.

The main difference between the various certifications analysed lies in the energy and built-environment impact criteria they consider, as well as the weight they assign to each.

In addition, each region sets criteria according to its climate zone and local culture, resulting in rating systems designed to be applied in a specific location.

Some systems also award credits for compliance with building regulations. This makes evaluation or comparison between schemes difficult, as their baselines, scope, and indicators differ.

In this article, we will focus on analysing the certifications in the first group due to their relevance and recognition, and we will add VERDE in Spain, which is the most prominent in our country, and WELL in the US due to its focus on one of the growing concerns—especially after the global COVID pandemic—namely users’ health and wellbeing.

LEED in the US

The LEED certification was developed by the US Green Building Council in 1993, the oldest GBC in the world—an increasingly influential private non-profit organisation whose aim is to promote sustainability in the design, construction, and operational phase of buildings.

The name LEED is an acronym for Leadership in Energy and Environment Design. It is a widely used international certification that has been applied in more than 30 countries beyond the US, and by 2014 it had certified more than 7,000 projects, or the equivalent of 140 km² of built area.

The LEED system includes 21 adaptations for different types of construction, designed to cover the needs of a wide variety of market sectors. The main categories distinguish between new construction and major renovations, which it calls ‘core & shell’, while also covering a broad range of building types, from residential to non-residential, primarily considering uses such as schools, retail, data centres, warehouses and distribution centres, hospitals, and healthcare. [3]

The rating system is based on a comparative label that totals a series of credits obtained from the positive assessment of certain features within each category, with the primary focus on energy and ecology. Documentation must be submitted for verification after the design phase and again during the construction phase to confirm that the project has been executed in accordance with the declared standards.

To this end, LEED produces a reference guide designed to develop projects alongside the rating system, serving as a roadmap that describes the steps to be met, offers best-practice advice, and provides general application examples.

For each established category, sustainability and its specific market factors are analysed. The highest standard is referred to as exemplary performance, and it identifies the maximum threshold that should be aimed for whenever possible.

In line with its international scope, the guide includes a section of international guidance to determine equivalence with US standards by using standards from outside its country of origin. In certain situations, it specifies a series of local equivalents—an alternative to LEED reference standards specific to a project’s location—that lead to similar or better outcomes.

To ensure correct application of the certification through an integrative process, the system distinguishes three phases: discovery, design and construction, and the operational phase. It insists that the discovery phase is always the most important, as it is unlikely that a project will meet its environmental goals cost-effectively without an analysis of the natural resources available in the area, following the principles of bioclimatic architecture.

In the implementation phase, or design and construction, schematic design begins, integrating all the prior work of collectively understanding the system’s interactions with its surroundings, achieved during the discovery or pre-design phase. Finally, focusing on the operational phase is essential to measure the impact of building use and to create feedback mechanisms or identify the need for any corrective action.

BREEAM in England

The BREEAM certification is the oldest in existence. It was developed by BRE, the Building Research Establishment, in 1988, when it was still a public building science centre of the UK government, before being privatised in 1997. BRE provides research, consultancy, training, testing, certification, and standards for public- and private-sector organisations in the UK and abroad.

It is a certification that stands as the leader in the European market, representing more than 80% of all sustainable commercial building certifications in Europe, with more than 250,000 certified buildings. [4]

It is present in more than 50 countries and has 8 National Scheme Operators, including England, Spain, the Netherlands, Norway, Sweden, and Germany. BREEAM ES in Spain is operated by the Instituto Tecnológico de Galicia (ITG), a private non-profit foundation that has been the exclusive certification body in Spain since 2010.

BREEAM has the highest uptake in the EU as a voluntary environmental certification scheme for non-domestic buildings and is used mainly for new buildings. Clients who choose it want the benefits of improved image and brand, as well as energy and environmental savings. An “in-use” version is available, but it is not widely used.

As the oldest scheme, it has also had more time to develop, through a combination of specific versions and a generic version with international ambitions. It was originally focused on office buildings, but it has developed variants for buildings in education, industry, retail, healthcare, courts, and prisons. The Spanish adaptation of BREEAM establishes five different certification schemes: for new non-residential buildings, housing and urban planning, existing buildings (non-residential only), or a bespoke version, although it is used mainly for new buildings. [5]

All these schemes assess building sustainability according to ten categories, each made up of a certain number of requirements set out in a series of Technical Manuals, with a final checklist that makes it possible to establish a comparative score. [6]

Following this comparative scheme, a final score is obtained, which is weighted according to national versions—for example, water is weighted more heavily in dry climates. Depending on the final result, the building is classified in the following ranking: Pass, Good, Very Good, Excellent, and Outstanding, which in international schemes can be translated into 1 to 5 stars.

Overall, BREEAM places weight on different aspects: the most common ones such as ecology and energy, but also criteria that are increasingly relevant, such as the health and comfort of those who live in, work in, or use the building, and the design and management process—covering the project process as well as construction, use, and demolition phases.

DGNB in Germany

The German Sustainable Building Council, a non-profit association founded in Germany in 2007, developed the DGNB certification two years later.

It is a certification system that by 2019 was already present in more than 40 countries worldwide, with more than 5,000 certified buildings and 4,000 qualified experts, according to data from the Green Building Council España, which became an official partner of the system that same year and acts as the certification body for DGNB projects in Spain. [7]

Implementing the DGNB System in each country requires adaptation to that country’s specific conditions. For this reason, GBCe is responsible for adapting this German certification to the Spanish market, taking into account the country’s climatic, regulatory, economic, and cultural particularities.

DGNB provides a planning and optimisation tool to assess sustainable buildings and urban districts, distinguishing up to 13 different building types. Within new residential buildings, it establishes a certification system for apartment blocks, as well as a system for new small residential buildings with fewer than 6 units or single-family homes. However, it currently does not have a system for existing residential buildings, as it focuses on certifying commercial buildings, for which it launched a new system for existing buildings in 2013, since it considers certification of the existing stock to be where energy use can be most influenced.

This scheme is based on the concept of holistic sustainability, placing equal emphasis on the environment, people, and commercial viability, each weighted equally at 22.5%. It also analyses the life-cycle impact of technical quality (15%), processes (12.5%), and the site (5%). [8]

In summary, it considers the following key issues to define the concept of sustainability:

– Putting people at the centre

– Promoting the circular economy

– Considering comprehensive design quality

– Supporting the Sustainable Development Goals

– Protecting the climate

– Fostering innovation

The DGNB system weights criteria according to the building type, a classification largely based on use: administrative, educational, residential, hotel, small retail, shopping centres, retail premises, logistics, production, and conference centres. The assessment is carried out by calculating a performance index from the value of each of the six areas. Finally, depending on the levels of compliance, different awards are granted: DGNB Platinum (> 65%), Gold (> 50%), and Silver (>35%).

PassivHaus in Germany

Alongside DGNB, the Passivhaus certification was also created in Germany, and both systems are widely accepted in their country of origin.

It was developed by the Passivhaus Institut in 1988, making it, along with BREEAM, one of the oldest certifications. It is currently present in more than 15 countries and has assessed more than 30,000 buildings. In fact, there is a database called the Passive House Database, which allows you to filter and discover all certified buildings on a map.

Its name comes from the concept of passive architecture, widely discussed in our Research section in articles such as Designing a Passivhaus home and How a Passivhaus home works.

In fact, the Passivhaus standard describes so-called nearly zero energy buildings (NZEB), which have recently begun to be regulated in Europe, with each country setting its own limits.

Therefore, following the distinction between nearly zero energy buildings (NZEB) and nearly zero impact buildings (NZIB), it is a certification that only evaluates energy performance and not other ecological footprint criteria. However, a positive aspect is that it considers the local climatic conditions of the project site, setting different limits depending on the country in which it is located.