Plastic in buildings: sorting is only half the job

Norwegian construction is good at sorting waste, and we are rightly proud of our sorting rates. But sorting only moves the plastic one step. What counts is what happens next, and today the answer is too often incineration.

Plastic is only a small part of construction waste, about 2 per cent by weight.¹ But it is carbon-intensive. When we burn it, we lose both the material and the energy that went into making it. Recycling plastic from buildings and infrastructure mechanically could cut around 200,000 tonnes of CO₂ a year in Norway.²

Specific rules, not stricter ones

We are not short of general goals. What is missing are specific requirements for plastic in buildings: for recycled content, recycling targets and reporting. Virgin plastic is still cheaper than recycled plastic, and nothing in today’s rules changes that.³

One important step is producer responsibility. For packaging, this is already in place: the EU's Packaging and Packaging Waste Regulation (PPWR) has applied in EU member states since 12 August 2026 and sets requirements across the entire packaging value chain, from production and use to reuse and recycling. In Norway, the Norwegian Environment Agency has proposed that the new regulations take effect on 1 October 2027, provided that the PPWR has been incorporated into the EEA Agreement by then.⁴ For building products, however, producer responsibility is not expected until after 2030.³ We should not wait that long. Waste from building sites is already registered electronically, and we can build on those systems.

The old roof has to come off

A Protan SE 1.6 membrane weighs about 2 kg per square metre,⁵ against about 4–5 kg for a single-layer bituminous membrane serving the same purpose.⁶ Less material means less to produce, transport and dispose of. Our membrane has a documented service life of at least fifty years,⁷ but so do bituminous membranes. Long life is not what sets us apart.

What matters is what happens when the roof is replaced. Historically, common practice has been to leave the old membrane in place and cover it over. It should be taken off and recycled.

Mechanically fastened or vacuum-installed thermoplastic membranes are easy to take off and come off clean. Fully adhered or heavy membranes are more challenging.

Old roofs were made with the chemistry of their time. That is a task, not a problem. We know what is in our membranes and how to handle it, and our products are analysed and declared according to the rules in each of our markets. Burning a membrane recovers a little energy and loses everything else. Recycling keeps the material.

Taking back our own material in a closed loop is a major achievement. The next step is an open loop, where recycled plastic moves across industries and sectors and ends up in more products. To get there, the industry needs to map what other plastic building products contain, so that recycling becomes a system rather than single projects.

What we are doing

Our first priority is to avoid waste, something we have worked on for many years. Through PROcycle we recycle our own production waste and take back offcuts from building sites, which become post-industrial recyclate (PIR). Protan SE membranes sold from August 2024 can be returned at the end of their life and recycled into post-consumer recyclate (PCR).

Our environmental product declaration assumes the membrane is burned at the end of its life, because that is what happens today.⁵ I think that is right: it shows in black and white what needs to change. If three out of four old roofs were recycled, indirect emissions from Protan in Norway would reduce its annual CO₂e emissions by approximately 80%.⁸

What I would like to see

• Measure what is recycled, not just what is sorted.
• Producer responsibility for plastic building products, built on the waste registration systems we already have.
• Old membranes taken off and recycled at renovation, with easy-to-dismantle fastening as the default.

This article builds on Protan Mythbusters, our video and podcast series, where our CEO Thomas Mørch, Kjetil Larsen of the polymer research institute Norner and our R&D director Lars Anisdahl test the claims made about plastic, including our own.⁹

Sources

1. Multiconsult and Mepex for Handelens Miljøfond, Plastgjenvinning i bygg og anlegg i et sirkulært perspektiv. Hovedrapport, January 2023.
2. Asplan Viak, Klimafotavtrykk bygg og anlegg; Mepex, Plastgjenvinning i bygg og anlegg; Protan analysis.
3. Overview of regulation for plastic packaging and plastic in buildings. Lars Anisdahl, PROcycle – retur og gjenvinningsordning for plastbaserte takbelegg, Forum for miljøkartlegging, 4 November 2025. See also Regulation (EU) 2025/40 on packaging and packaging waste (PPWR).
4. Norwegian Environment Agency, Foreslår nytt regelverk som skal gi mindre emballasje, 19 September 2026, and Emballasje; Emballasjeforeningen, Miljødirektoratets forslag til gjennomføring av PPWR i Norge er klar, 21 September 2026.
5. The Norwegian EPD Foundation, Environmental Product Declaration NEPD-12037-11981: Protan SE 1.6 Roofing Membrane, issued 19 August 2025. Weight 1.95 kg/m²; end-of-life scenario incineration with energy recovery.
6. SINTEF Certification, SINTEF Technical Approval TG 2022: Isola Mestertekk single layer bituminous roofing membrane, revised 12 February 2026. Area weight 4.6 kg/m² ± 0.3 kg/m².
7. ETA-Danmark, Technical Approval for Application TGA.2024/010: Protan SE, valid until 1 July 2028. Expected lifespan of at least 50 years, based on a field study of approx. 50,000 m² of roofing. Quality control by SINTEF; SINTEF Technical Approval TG 2010, revised 26 August 2024.
8. Protan analysis, indirect greenhouse gas emissions for Protan in Norway with 25 and 75 per cent mechanical recycling of old roofs. Lars Anisdahl, Forum for miljøkartlegging, 4 November 2025.
9. Protan Mythbusters, video and podcast series, episode with Kjetil Larsen, Norner, and Lars Anisdahl, Protan.