From LCA to the NMD database
‘The Assessment Method for Environmental Performance for Construction Works, or Assessment Method for short, is a uniform measurement method for calculating the environmental performance of buildings in an unambiguous, verifiable and reproducible manner. For that purpose, the Method of Assessment is adopted based on scientific life-cycle assessment as set out in EN 15804, the European standard for the environmental life-cycle assessment of construction products.’
The life cycle assessment (LCA)
An LCA is a quantitative method to determine the total environmental impact over the entire product life cycle; from raw material extraction and production to end-of-life use and disposal (see figure below). It allows companies to understand the environmental impact of their products and raw materials through the entire value chain. The life cycle of a product in a structure is divided into 4 modules (A to D, where B6 and B7 are excluded in the Assessment Method). LCA is performed using software programmes such as SimaPro. These programmes make use of databases such as the NMD process database and Ecoinvent, which contain environmental data at detailed level on, among other things, production processes, energy generation and transport both nationally and internationally. The Assessment Method for Environmental Performance of Construction Works, in combination with EN 15804 and the related ISO standards, outlines the ground rules for drawing up an LCA for the environmental data in the NMD.
What is an LCA?
When drawing up a 'Life Cycle Analysis' (LCA), you measure the effects of a product on the environment in its various life phases. In the EN 15804 LCA methodology, 19 categories of environmental impacts are examined. These include effects related to the depletion of our resources (use of raw materials, energy, water and land) and to the emission of harmful and hazardous substances (greenhouse gases, nitrogen and toxic substances). In short, an LCA examines for a product the withdrawals from the environment and the emissions to the environment. The study is carried out with regard to all life phases of the product, i.e. from extraction of raw materials through production, use and reuse to waste disposal. In other words, from cradle to grave.
What is the purpose of an LCA?
The outcome of an LCA is a score matrix of environmental impacts for each indicator at each stage and is referred to as the 'environmental profile' of the product. A single score is then derived from the environmental profile: the 'Environmental Cost Indicator', or MKI for short. In the Civil Engineering sector, the environmental profile of a viaduct, for example, is expressed in ECIs. In the building sector, the 'Environmental Performance of Buildings' (MPG) is a calculation of the ECI per year of life of the building and per square metre of gross floor area.
When applying for an environmental building permit, an Environmental Performance of Buildings calculation is required to be submitted and the Environmental Performance of Buildingsmust meet a certain value. Currently, newly built residential buildings are not allowed to have a higher MPG higher than 0.8. Newly built offices with a usable area larger than 100m² may not have a higher MPG higher than 1. In the future, the aforementioned values will be lowered and other building functions will also have to comply with a requirement for MPG. In the civil engineering sector, the MKI is used to factor environmental quality into procurement projects. The MKI is then a factor in the calculation of the 'Best Price-Quality Ratio'. In addition, the MKI calculation plays a role in establishing building labels (such as BREEAM and GPR-Gebouw) and obtaining tax benefits (MIA or GPR-Vamil scheme).
The sum of all environmental profiles makes it possible to value the environmental quality of the construction projects. Clients, designers and government can then use the same indicators to formulate goals to improve the environmental quality of the impact of the construction sector.
The LCA, which is the basis for the environmental profile, provides the producer of the building product with a tool to improve the environmental quality of the product. The analysis shows which environmental impacts occur at what time and to what extent. The improvement can be achieved, for example, by using raw materials that are renewable or recycled, by using a modified product composition to reduce harmful emissions, by producing with non-fossil energy, by reducing the transport distances of raw materials and semi-finished products, by reducing the shape the mass of the product, by using power tools and equipment on the building site, by using more robust components to extend the service life, by using new fastening techniques to increase the detachability and reusability of the product, etcetera. As the LCA covers all life phases of the product, the opportunities for improvement are very diverse.
What does the National Environmental Database do with an LCA?
The NMD is basically a library of environmental profiles. With these publicly accessible environmental profiles, the NMD provides designers, builders and building owners with a tool to determine the environmental quality of structures. Using specific calculation software, which aggregates all environmental profiles of a building structure, the environmental impact of that structure can be calculated.
Since some environmental data is part of 'the master's secret', an LCA is converted into a public summary without sensitive information and is then called an 'Environmental Product Declaration' (EPD). The LCA report, also referred to as 'EPD Background Report', is for internal communication only and can be used by the manufacturer or supplier to identify where environmental quality improvements are meaningful and feasible.
How is an LCA developed?
The preparation of an LCA requires the collection of all relevant environmental data. In practice, data collection has proven to be a time-consuming and labour-intensive process. Best-case scenario, it could take a few months to collect the data. In extreme cases, a few years go by before all the data is collected. data that the manufacture can get directly from its own production process are more readily available. It is a lot More difficult to request data from foreign suppliers. Sometimes the data cannot be retrieved. For certain data, such as transport distances and energy consumption, data from general process databases are used. In many cases, these values are more conservative. If one wants to use values specific to the product, this has to be substantiated on a scientific basis.
An LCA is commissioned by the manufacture or the industry. This can be done by an internal employee. But many organisations outsource this work to an external LCA consultant. It has been shown that knowledge and experience in LCA plays a major role in the progress and quality of the final result.
It is important to establish in advance the purpose for which the LCA is being prepared. If the development of the LCA aims to add the product into the NMD, the LCA performer should take into account the requirements for the inclusion of environmental profiles in the NMD. For example, specific requirements apply to the data collected regarding materials and background processes. A specific database is referred to for the collection of such data. The version of the database is also important.
The process of collecting necessary data is called the 'Life Cycle Inventory' (LCI). A plan is drawn up to determine which data need to be collected. Once the data are complete, initial calculations are made. The calculations are discussed internally in the company or industry and can be adjusted based on a justification. Then the calculations are finalised and the report can be prepared: the internal EPD Backgroundreport and public summary in the form of an EPD
The LCI varies greatly from product to product. For one product, the LCI is a complex event; for another, it is simple. A general and unambiguous description of the LCI is therefore not possible. To get an impression of the data collection process, the following is a description of some aspects and questions that characterise the LCI.
- Data collection starts with noting the product name and accurate description of the product, such as dimensions, weight, among others. The intended use and area of application should also be carefully described.
- The origin and composition of substances, materials and components (all ingredients) of the product should be noted, including the secret ingredients and minimum added substances.
- How is the product manufactured? Each step in the process should be described, such as heating, washing, cutting, welding, painting, gluing, pressing, coating, drilling, etc., etc., etc. The manufacturing process is shown in a flow chart.
- Is water and energy needed for production? If so, how much and what kind? Does it involve tap water or groundwater? What is the energy source; fossil energy, waste heat, biomass, wind or solar energy or anything else?
- The waste material in production is recorded. Questions that are answered here include: how much waste is there and what happens to the waste. Does it go back into production, is it sold to third parties, is it used internally for incineration or heat generation?
- How is the product packaged and transported? Is it transported to the site by electric equipment or diesel?
- What specific advantages does the product have? For example: only EURO 5 or 6 trucks are used, it is always Lean transport, there is a take-back programme. Such advantages should be demonstrated with evidence.
- How do you allocate the values of environmental impacts when a process or product system produces or processes multiple materials or products (the 'allocation')? Allocation is usually determined by the value the product generates. For example, if 90% of a sheep's yield is determined by its meat and 10% by its wool, the environmental impacts of sheep manure are allocated accordingly between the sheep meat and the sheep wool.
- How will the building product be processed on site? Is large equipment needed as for example a crane. Is it an electric crane and does the crane run on diesel? What and how many fixing materials are used? What happens to packaging materials and construction waste? Are there any cutting losses?
- What is the expected lifetime of the product? What is the effect of general maintenance on service life? What does general maintenance consist of and how often? Is repair possible? Can the product be easily replaced?
- What happens at the end of the product's life, such as after replacement maintenance or demolition of the building? Can the product (building part or installation part) be easily dismantled without breaking damage to the rest of the structure or installation? Is heavy equipment required during dismantling? What is still possible with the product? Is it suitable for reuse, recycling, refurbishing? Or will it go to the incinerator or landfill?
Inclusion in NMD
When the LCA owner chooses to have the building product included in the NMD, the LCA performer enters the environmental data and the LCA background report into the NMD. To access the online entry application, the LCA performer must request permission from the NMD. The input determines how the building product is categorised in the NMD. This is important for the findability of the product.
Next, the LCA and background report are checked by a 'recognised LCA expert'. This recognised expert checks ('reviews') the submitted environmental data and LCA report from an external and independent position. The reviewer's approval is required for the final inclusion of the environmental profile in the NMD. Even after inclusion in the NMD, the commissioning company or industry retains ownership of the environmental data and, as LCA owner, remains responsible for the quality of the environmental data.