4 min

Innovating for sustainable construction: a new era for life cycle assessment

Read all about LCAs, EPDs and technology that automates the process

With a growing focus on climate change and the global goal of limiting the temperature increase to 1.5˚C, it is becoming increasingly important to understand where our environmental impacts are coming from, in order to limit them. This is especially true for the construction sector, where a single building can contain thousands of elements, each with potentially thousands of different impacts.

One approach widely taken in construction is recycling – a building contains too many materials to dispose of in landfill, for example, and recycling can significantly lower the cost of a project. We look at one of the ways to assess the impact of construction: life cycle analysis.

Certifying circular construction materials

The construction industry is already moving towards a more circular model, and Kiwa aims to support companies in their sustainability efforts. NIBE, which has been part of the Kiwa Group since 2018, has been providing research, consultancy and design services related to the environment, health and construction for three decades. As advisors for sustainable construction, they work with a broad range of clients, from property developers to building product manufacturers.

NIBE’s team of environmental analysis experts are engaged in quantifying the impact of construction products on the living environment. According to NIBE Managing Director Mantijn van Leeuwen, about 80 percent of the work they do involves developing and advising on Environmental Product Declarations (EPDs) and how to use them properly. EPDs are the verified results of life cycle analysis of products, showing their environmental impacts.

“We do assessments for buildings, but also infrastructure – highways, tunnels, bridges, railways and harbors, for example,” Mantijn said. “It all comes down to the building products that are in the construction, which are made up of materials that need to be assessed for their environmental impacts.”

Mantijn van Leeuwen-NIBE.jpg

Mantijn van Leeuwen, Managing Director of NIBE.

What is an LCA?

To assess a construction product’s impacts, Mantijn and the team need to look at its component materials and processes separately and build a model. This is done through life cycle assessment (LCA). A product, which is known as a ‘functional unit’ in LCAs, has impacts throughout its life cycle: through raw materials extraction, transport processes, production processes, maintenance, replacements and end-of-life use.

An LCA assesses every aspect for all components. This can be a massive undertaking: there can be hundreds of chemical and material flows in a product. In its LCA model, NIBE currently calculates 69 environmental effects – those currently used in all national methods in Europe. This number is increasing, with new impacts added to the model frequently.

Not all the LCA results go into the EPD, because it would become unreadable and less meaningful in practice. Instead, 19 of the 69 effects are added to the EPD, resulting in a summary that is understandable to professionals like architects and project managers. “A non-expert could get a first impression from an EPD and understand the impact of a product by reading the summary table,” Mantijn said.

This is one of the key benefits of the EPD: an architect or construction firm can use them to gain information about the environmental impact of the products they are considering using and make decisions to ensure their projects are as sustainable as possible.

EPDs are currently not simple to compare. They can only be compared like-for-like, and three aspects need to match for a useful comparison: the functional unit itself, the method of calculation used, and the database used. But the situation is changing – developments in the timeframes, comparability and coverage of EPDs are ensuring they become more usable and valuable in the future.

Moving from voluntary to mandatory EPDs

Norms and standards are helping ensure EPDs are comparable and useful. EPDs are currently voluntary in Europe, and they fall under a few main norms:

  • ISO 14040 Environmental management — Life cycle assessment — Principles and framework
  • ISO 14044 Environmental management — Life cycle assessment — Requirements and guidelines
  • NEN-EN 15804 Sustainability of construction works – Environmental product declarations

LCAs for all construction products and services are based on the same rules to generate EPDs. These are stipulated in the European norm EN 15804, as part of the work program of CEN/TC 350. These norms are crucial to establishing a sustainable and circular construction sector, as they standardize the way in which environmental data is generated and communicated.

Regulatory efforts to encourage their use have not yet resulted in lower environmental impacts. Relatively few manufacturers go through the LCA process because it can be costly, and many do not perceive enough of a commercial benefit.

For some, though, the benefit is potentially huge: the main organization responsible for infrastructure in the Netherlands – Rijkswaterstaat – offers financial bonuses as part of their tenders for companies that make sure construction projects are as sustainable as possible – and these bonuses can run into the tens of millions of euros.


Although incentives have so far been more effective than regulation, there is change ahead: a new European regulation is expected in 2022, which could significantly increase the number of products undergoing LCA.

Today there are about 3,500 EPDs in the database for the Netherlands, 30,000 for Europe and 80,000 globally. To put the expected impact of the regulation into perspective, Mantijn estimates that about 3 million EPDs will be needed to cover the market by the end of the new regulation’s two-year transition period.

“It's still a big step to take,” Mantijn said. “We took 20 years to get to 30,000, and now we have two years to get to 3 million. It’s challenging, but it’s doable if we automate the process and put it in the hands of the manufacturers themselves.”

Decades of development

The founder of NIBE was an architect who wanted to create sustainable constructions. But in the 1980s there wasn’t much information to work with. He started doing LCAs to understand the products he wanted to use in his designs. The methodology he used with NIBE, alongside a handful of other pioneering companies, formed the basis for the Dutch approach, which was then adopted across Europe and around the world.

The cornerstone of the approach is the national database, where EPDs are accessible for those who need to use them. The database has software attached to it that helps users understand the information. For example, architects can look in the database and put in a building design, then select all the available products. As well as choosing the more sustainable options, they can get an overall total number for the building, reflecting its total environmental impact.

“For architects and designers, the process is simple,” Mantijn said. “They can use the EPDs in de national database, and they can do the calculation for a design in one day, more or less. They find that an acceptable workload, so it means they are more likely to do it.”

But there is a major challenge: EPDs only need to be renewed every five years currently. Because the models and information used are changing so quickly, the numbers can be as much as 30% out over the course of five years.

Mantijn is aiming to reduce the time between assessments. If EPDs had to be updated every two years – or better still, annually – they would be more accurate and therefore more effective. If done manually, more frequent LCA assessments would be expensive, therefore potentially putting manufacturers off the process. But with technology, companies could maintain a portfolio of up-to-date EPDs easily and efficiently, thereby encouraging more sustainable construction decisions.


R<THINK life cycle analysis

Companies working with NIBE currently update their LCA and EPD every two years. But since they use data for a full year, it makes sense to move them all to annual assessments.

With the forthcoming European legislation, which is expected to make it mandatory for construction sector manufacturers to have EPDs for their products, Mantijn foresees a significant increase in demand for LCAs. Although NIBE has a growing team of experts, they will not be able to meet the accelerating demand by doing only manual assessments.

Mantijn believes the answer is technology. Over the past six years, the NIBE team has been developing R<THiNK – software that enables companies to carry out their own LCAs and produce EPDs based on ISO 14040 and ISO 14044. The idea is that NIBE provides the models and data, and the customer pieces the information together like a puzzle. This makes it faster and cheaper for them to maintain their portfolio of EPDs – sometimes in the hundreds.

Mantijn and his team are starting to onboard Kiwa customers using R<THINK. “It's a massive task to onboard all these companies on the platform, but once they are in, they can start doing it themselves,” Mantijn said. “We're proud of the platform, because it works well, and I think this will be the key to upscaling the use of LCAs and EPDs.”

Replacing harmful materials

Mantijn believes in the coming years, many less sustainable materials will be under pressure – including steel and concrete. As well as reuse and recycling, he believes one other factor will be key as we move to a more sustainable construction industry: “If we keep doing what we’re doing today, the future we want will not be possible. We need innovation.”

Innovation, he explains, could not only give us new ways of approaching LCAs, but also entirely new sustainable materials. NIBE works with Bitufa on EPDs for their lead-free replacement materials. Bitufa has been producing bituminous waterproofing membranes for 40 years, but when the European Green Deal stated that fossil materials will no longer be allowed after 2050, founder and director Roeland van Delden had a problem to solve.

“I started to be creative together with my team,” he said. “We decided it might be clever to use unusable plastic waste as raw material. We investigated many different types of waste, like polyester, polyethylene and polypropylene, but nothing had the characteristics I was looking for. Then we found polyvinyl butyral waste – PVB – which is now what we use in our Leadax material.”


Roeland van Delden, director Bitufa.

PVB is a plastic film that was used in safety glass – in car windscreens and building windows, for example. It is considered ‘unusable’ plastic waste because it is difficult to separate cleanly from the glass. After several years of research, Roeland and his team created the first PVB-based product: Leadax, a lead replacement. They manufacture durable and recyclable Leadax waterproofing membranes using solar power, so the process is climate neutral.

They believed Leadax is far greener than lead, even before taking the biodiversity impacts of lead into consideration, so Roeland contacted NIBE to conduct an LCA. The results showed that Leadax is more than 30% greener than lead.

Bitufa was able to use the LCA results in the EPD to start selling the material. They now sell their flashing membranes through partners based in different countries, and their newest innovation, Leadax Roov, is distributed in Europe by Wienerberger.

“I believe that everybody who starts to use our new material will care about the environment, so they will be looking at the database of EPDs to make choices. They will see our products at the top of the list – that gives us a very good competitive advantage. It’s quite a contest, and that helps everybody to make the world a better place.”