Nordea ESG analyst Martin Zistler stands in his cross-laminated timber (CLT) house in Espoo, Finland, surrounded by 63 cubic metres of wood. Looking up at the rafters, he estimates that the house stores around 80 tonnes of carbon dioxide, roughly equal to the six-year carbon footprint of his five-person family living there.
CLT, a kind of mass timber produced by laminating slabs of wood together, is one of the materials in green building. On par with the performance of concrete or steel, the green building material has been touted as a solution to help to decarbonise the building sector.
While examples such as Martin Zistler’s timber house in Espoo are exciting to some, they may seem like a drop in the ocean. After all, buildings in the EU are responsible for 40% of energy consumption and 36% of carbon emissions, mainly stemming from construction, usage, renovation and demolition.
So is all the buzz around green buildings overblown hype, or can they really help mitigate harm to the environment? According to Martin Zistler, the benefits are real.
“A green building reduces or eliminates negative impacts and can even create positive impacts on our climate and natural environment,” he says, citing the World Green Building Council.
In addition, eco-friendly building can also result in lower operating costs and an increased building value, making both environmental and financial sense, he adds.
We’ve only truly succeeded when we no longer need to speak about green buildings but instead make them the standard way of building.
Incentives for greener buildings
At the extreme end of the spectrum, we could reduce the environmental impact of buildings by foregoing them entirely or downsizing considerably. Alternative forms of living, such as nomadism (digital or otherwise), year-round camping and tiny houses are small but well-publicised trends.
Short of such dramatic lifestyle changes, we can work to decrease buildings’ negative impact. Across the EU, regulation seeks to do just that, including the Net Zero Energy Building Directive (nZEB) as well as long lists of local building requirements.
Larger real estate companies are also required to adhere to the Non-Financial Reporting Directive, including disclosing their alignment with the EU taxonomy. They are also advised to follow the Nordea Sector Guidelines and the recommendations of the Task Force on Climate-related Financial Disclosures (TCFD).
In addition to regulations and recommendations, green housing loans provide incentives for environmentally friendly buildings.
How to build green
Martin Zistler notes that planning a new building ideally starts with mapping and understanding the actual needs and risks. Building risks can include acute and chronic physical risks related to climate, such as floods, heat and soil erosion; transition risks due to new regulations, technology, market and consumer sentiment; biodiversity and community impacts as well as safety risks including fire, material and health risks.
Once the need for a new building is validated and the risks are understood and managed, there are many options for building in a clever and efficient way. These include conserving resources by reducing building volumes; prolonging the building’s lifespan; using pre-fabricated low-waste production processes and making the building flexible and adaptable.
Materials such as timber, cork, algae bioplastics and latex carry a smaller carbon footprint and may even store considerable amounts of carbon. Solar reflective paint, bacterial nanocellulose and concrete substitutes (e.g. desert sand and fungal mycelium) as well as traditional cob (a mix of soil, water and straw) are other potential, more sustainable building material options.
Biomimicry can be used to emulate natural systems to minimise the use of materials and even remove carbon dioxide, for example, by mimicking the bio-mineralisation process. A number of companies including Blue Planet and Biohm are experimenting with alternative building materials.
When it comes to building usage, optimal design may include water saving, heating and cooling measures. Finally, reversible design ensures that the building can be disassembled at the end of its lifespan and the components upcycled, reused or recycled instead of going to waste.
Environmental harm can also come from the construction site, related to waste, noise, energy, water, transportation and the risk of spills and construction failures. Digital controls and monitoring as well as information management can help reduce these impacts. On-site 3D printing and pre-fabricated ready elements including cross-laminated timber allow for more precise construction compared to traditional construction methods. In addition, sourcing materials locally can help reduce the building’s transportation footprint and creates local demand.
The renovation wave
Martin Zistler notes that, despite all good ideas,, new buildings only make up 1 to 2% of building stock annually. The EU targets a climate-neutral Europe by 2050. However, of all the buildings likely still in use by 2050, around 70% of building stock is energy inefficient, and only an average of 1% of buildings undergo an energy-efficiency renovation each year.
The EU renovation wave addresses that challenge and seeks to double the renovation rate, with the goal of 35 million renovated buildings by 2030, thereby decreasing carbon emissions and avoiding stranded assets (buildings that suffer a premature loss in value).
Renovations can help reduce a building’s in-use energy demands, for example by adding weatherproof materials and insulation; better heating, ventilation and air-conditioning (HVAC) as well as energy efficiency monitoring to encourage changes in behaviour. In addition, on-site renewables including solar and deep geothermal as well as sourcing renewable electricity can further decrease greenhouse gas emissions.
The list of good practices is long, and many are validated by numerous academic and case studies, but they need to catch on broadly, Martin Zistler says, adding:
“We’ve only truly succeeded when we no longer need to speak about green buildings but instead make them the standard way of building.”