MPG calculation: lowering a building's environmental performance with fibre reinforcement

The MPG calculation (MilieuPrestatie Gebouwen, the Dutch environmental performance of buildings) expresses the environmental impact of all construction materials in a building as a shadow price per m² of gross floor area per year. Since 1 July 2025 a limit value of 0.5 has applied to new-build homes. Fibre reinforcement lowers the MPG because CO₂-intensive reinforcing steel is largely eliminated and structures last longer.

What is the environmental performance of buildings (MPG)?

The environmental performance of buildings is the statutory measure of a building's material-related environmental impact. For every construction product used, the impact is determined via a life cycle assessment (LCA) — from raw material extraction and production to transport, replacement and the waste stage. Those effects are weighted into a single notional amount of environmental cost, totalled for the whole building and then divided by the gross floor area (GFA) and the building's service life. The result is a shadow price in euros per m² GFA per year: the lower, the better.

Because the load-bearing structure — foundations, floors, walls — is the largest material item in most calculations, the choice of concrete and reinforcement weighs heavily on the final score. That is exactly where the gain of fibre reinforcement lies. In our pillar overview sustainability, standards and innovation you will find the surrounding standards articles.

When is an MPG calculation required?

An MPG calculation is required when applying for a permit for new-build homes and for offices larger than 100 m². The requirement is laid down in the Dutch Buildings Decree (Besluit bouwwerken leefomgeving, Bbl); the competent authority checks the calculation when granting the permit. With the tightening of 1 July 2025, the system has also been broadened, so that other building functions now have an environmental performance requirement too.

In practical terms this means: anyone submitting a new-build project without a sound MPG calculation, or with a score above the limit value, will not receive a permit. Material choices that push the score down — such as fibre reinforcement that lowers the structure's MPG contribution — are therefore no longer an optional sustainability ambition, but a permitting instrument.

MPG requirement 2026: limit values and tightening

The limit value has been tightened step by step since its introduction:

• 2018 — first limit value: 1.0 €/m² GFA per year for homes and offices.

• 1 July 2021 — tightened for homes to 0.8.

• 1 July 2025 — homes to 0.5 and offices to 0.85, combined with an updated assessment method that weighs more environmental impact categories.

• 2026 — the limit values of July 2025 remain in force; towards 2030 the national government is steering towards further tightening.

The jump from 0.8 to 0.5 for homes is substantial: a design that comfortably complied in 2024 may exceed the limit in 2026. Because the structure is the largest item, the structural frame is the logical place to optimise — with slimmer structures, circular raw materials and less reinforcing steel.

How does the MPG calculation work?

An MPG calculation follows the Dutch Environmental Performance Assessment Method for Construction Works and proceeds in five steps:

• Determine quantities — all materials in the design are quantified (m³ of concrete, kg of reinforcement, m² of façade).

• Link to the National Environmental Database (NMD) — each product is assigned a product card with verified environmental data. Category 1 and 2 cards are verified; unverified category 3 data carries a 30% surcharge on the environmental costs.

• Weight the environmental effects — effects such as climate change, acidification and resource depletion are converted into euros via shadow prices.

• Sum over the life cycle — including replacements during the building's service life (standard 75 years for homes, 50 years for offices).

• Divide by GFA × service life — the result is the MPG score in €/m² GFA per year.

Calculation software such as GPR Materiaal or MPG assessment tools performs these steps, but the outcome is only as good as the input. Products without their own NMD card fall back on generic category 3 data with the 30% penalty surcharge. Therefore always ask suppliers for product-specific, verified environmental data — exactly which documents to request is covered in our article on sustainability certification of fibre materials.

What is the difference between MKI and MPG?

The environmental cost indicator (MKI) and the MPG measure the same thing — weighted environmental costs — but at a different level. The MKI is an amount per product or per object (a m³ of concrete mix, a kilometre of carriageway) and is the award criterion in civil engineering tenders via DuboCalc; by way of illustration: the European FIBRA research shows that fibre reinforced asphalt with standard penetration grade bitumen scores over 10% lower at cradle-to-gate level than a comparable polymer modified (PMB) mix. The MPG is the sum of all those product impacts for one building, normalised per m² GFA per year, and belongs with the building permit. If you work on infrastructure projects rather than buildings, read how fibre reinforcement counts in MKI and DuboCalc.

Worked example: fibre reinforcement instead of reinforcing steel

To see where fibres affect the MPG, it helps to look at the CO₂ emissions per m³ of concrete. A typical structural concrete mix sits indicatively around 250–300 kg of CO₂ per m³, excluding reinforcement. Traditional reinforcing steel adds around 0.7 to 2 kg of CO₂ per kilo on top, depending on the scrap content in the steel production. With a monolithic floor with double reinforcement mesh — easily 25 to 35 kg of steel per m³ — that quickly adds 10 to 20% on top of the concrete's impact, quite apart from transport and steel fixing.

A structural macro fibre is dosed at a few kilos per m³ — for a synthetic fibre such as TwistR, typically 3 to 5 kg/m³ depending on the loading. The fibre itself also has a production footprint, but the weight difference is so large that the reinforcement-related emissions virtually disappear: in the NDSM project, replacing reinforcement mesh with macro fibres delivered a 98% CO₂ reduction on the reinforcement. What such a calculation looks like per project is shown step by step in our CO₂ worked example with fibre reinforcement.

In the MPG calculation this feeds through directly: fewer kilos of steel means lower shadow costs for the structural frame, and thus a lower score per m² GFA. Note: fibres do not fully replace traditional reinforcement in every application — structural work always requires a calculation by the structural engineer.

Service life: the divisor in the MPG formula

The MPG converts environmental costs into an amount per year. Anything that lasts longer therefore pushes the score down: the impact is spread over more years and fewer replacement cycles are needed within the building's service life. Fibre reinforcement plays into this in two ways.

First, fibres control cracking, so floors and elements need less repair and earlier replacement. Second, infrastructure practice shows how large the service life effect can be: fibre reinforcement in asphalt delivers, depending on fibre type and application, potentially up to 50% longer road surface life and up to 200% longer life of the asphalt layer itself. Even if the initial production impact of a fibre reinforced mix is comparable or slightly higher, the annual environmental impact — and thus the MPG or MKI contribution — works out lower.

Circular concrete: the difference between an MPG contribution of 0.1 and 0.3

How wide the range between material choices is, circular concrete demonstrates: a recently introduced circular concrete product achieves an MPG contribution of 0.1, against 0.3 for traditional concrete. That threefold difference on the largest material item feeds straight through into the total building score — with a limit value of 0.5 for homes, that is often exactly the headroom a design needs.

Such low contributions arise from combining circular raw materials with smart reinforcement choices. In precast production the two come together: less steel, less waste and tight dosing control. Read how precast with fibres achieves a lower environmental performance — from wall panels to foundation elements.

How to lower the MPG of your project

If you want to steer the MPG calculation with fibre reinforcement, this is the practical route:

• Have your structural engineer calculate a fibre variant alongside the traditional design; standard EN 14889 and the associated CE marking safeguard the structural performance of the fibre.

• Match the fibre to the application: TwistR as a synthetic macro fibre that largely replaces reinforcing steel in floors and precast, or Basalt Wave where a mineral fibre with heat resistance up to around 700°C is desired.

• Request product-specific environmental data (EPD/NMD declaration) with every offer, so that your MPG assessor does not have to fall back on category 3 data with the 30% surcharge.

• Explicitly include the service life effect: a substantiated longer service life lowers the annual contribution.

Dutch Fiber Trading supplies the CE and environmental documentation with every quotation and calculates the steel saving of your design free of charge — request a quotation with MPG substantiation.