In this article Nick Turner, Head of Surveying, Woodgate & Clark, takes a look at the different materials used during property repairs and the low carbon alternatives.
The insurance industry has made good progress on setting net zero targets according to the ABI. One area that offers great potential is the choice of materials for building repairs. The good news is that there has been significant progress in recent years in low carbon alternatives to some of the most common materials used in construction. The next step is to find a way for these solutions to be specified for repairs, within policy terms.
Looking at the materials that have had the biggest impact – concrete is responsible for 1.5% of UK CO2 emissions (7.3M tonnes). However, since 1990, the absolute carbon emissions reduction of the UK cement and concrete industry has been 53%. Furthermore, the Low Carbon Concrete Routemap, sets out three decarbonisation routes to 2050. Even under the most modest route, emissions are expected to fall from 10m tonnes CO2e in 2022 to 5m tonnes in 2035. The most optimistic scenario suggests that the concrete industry could absorb more greenhouse gases than it emits by the 2040s.
Cement is used from brick and blockwork, to rendering and roof repairs. Every tonne of Ordinary Portland Cement (OPC) emits 622kg of Co2. The alternative is LC3 – a new type of cement that is based on a blend of limestone and calcined clay and can reduce CO2 emissions by up to 40%. It has a similar performance to OPC and can save up to 25% of costs in production. By reducing the use of OPC it is calculated that CO2 emissions will reduce by 2%.
Plasterboard is also used a lot in insurance repairs yet according to a study from the University of Bath, plasterboard was responsible for 3.5% of the UK’s annual emissions in 2017. It is an energy intensive product to manufacture. It is estimated that 300,000 tonnes of board waste a year is generated because of over-ordering, incorrect specification, damage, and off-cuts during construction.
Specifying lightweight products and eliminating waste material has the most impact when trying to reduce the carbon footprint of plasterboard. In the meantime, alternatives are being tested including a carbon-absorbing, sustainable and completely biodegradable plasterboard called Breathaboard.
When it comes to decorating, while there has been significant progress shifting from solvent based paints to water based, there is more work to be done.
Most water-based gloss paints are claimed to have at least 30% lower embodied carbon and contain 72% lower Volatile Organic Compounds (VOCs) than solvent based paints. However, solvent based paints are still considered superior for exterior use due to their weathering resistance compared to water-based paints. Longer lasting paint means fewer costs and less painting during the lifetime of a building. This obviously means fewer emissions.
More encouragingly we are seeing new paints come on to the market that not only claim to have 90% less embodied carbon than trade paints but also absorb CO2. One example is Ecosphere that has been awarded the Cradle to Cradle Gold Certificate. This is the leading multi-attribute standard used globally for designing and making products that enable a healthy, equitable and sustainable future.
Plastics are frequently criticised for everything from their toxicity to their contributions to ocean pollution, but not all plastics are bad, and they play an important role in reducing greenhouse gas emissions.
Being a versatile material, they are widely used in building and construction and unlike metals, plastics can be reused and recycled many times, without losing their chemical properties. Many are highly durable, long lasting and permanently installed, so they’re unlikely to become marine litter.
The most common plastics used in construction are polyvinyl chloride (PVC), high density polyethylene (HDPE), and expanded polystyrene (EPS). The main challenge in the construction industry is how to efficiently segregate, reuse, and recycle plastic waste at the end of its life. Unfortunately, building materials made from recycled plastics are not yet widely used in the construction industry but there are plenty of ideas and innovation. As technology develops for both the recycling and manufacturing processes, the use of recycled plastics will increase.
This means the construction sector could act as a ‘sink’ for waste plastics, utilising recycled plastics as a raw material and helping to improve domestic waste recycling rates. This is much needed. Plastic waste created in the UK amounted to an estimated 3.4 million tonnes in 2017, a third of which is sent to landfill.
The road to net zero
Embodied carbon from building materials accounts for about 20% of the carbon emissions from the building sector, yet there is no current policy to assess or control the environmental impact of materials being used. Even so, lower carbon materials for building repairs are slowly increasing in availability. As lower carbon material choices and costs improve, the insurance industry and its supply chain will want to have a wider discussion about the potential for changes in policy terms and wordings to allow some of these alternative products to be specified for repairs.
Read Woodgate and Clark’s series of articles on Low Carbon materials at: https://www.woodgate-clark.co.uk/media