Last year, the topic of home insulation became a topical national topic. It began when Insulate Britain activists blocked several of England’s major motorways. Protesters were imprisoned (one went on hunger strike), and a heated nationwide debate ensued over the tactics used by the campaign group.
But whether you approve of his methods or not, the problem remains that the UK has some of the oldest, most airtight – and therefore least energy efficient – housing in Europe.
Meanwhile, the construction pandemic accounted for 38% of all global energy-related CO emissions.2 emissions – this includes emissions from existing buildings and from construction, under the UN Environment Program.
“Because this is such a large share of global emissions, there is a significant opportunity to make a big difference – and decarbonisation of buildings may be a major part of the solution, but it will not be as easy as it seems,” said zero carbon pioneer Professor Lubomir Jankovic, director of the Center for Society Studies. future and founder of the Zero Carbon Laboratory at the University of Hertfordshire.
In the UK, houses should be built mainly, says Jankovic, because they will make up 80% of the housing stock in 2050 – the year in which the government has promised to reach zero.
“In total, there are 19.1 million houses that will still be used, but most of them are not energy efficient, so modernization is an important step,” says Jankovic. “According to my estimates, there are more than 10,000 days left until 2050, so we need to re-equip about 1,870 homes a day to achieve this goal. This puts the necessary scale of effort into perspective. “
For some facilities, upgrading or installing new facilities or systems may include improving insulation and improving the tightness of properties; for others it may require the addition of heat pumps, solar panels and, in the near future, a new type of hydrogen boiler. “Without re-equipment, we will not reach pure zero by 2050,” says Jankovic.
New buildings can also add to the problem. “At the moment, building codes do not require a new building to be zero, so we are helping to increase the number of homes that will need refurbishing, even if some are new.”
One of the main factors to consider is the carbon emissions in conventional building materials such as brick and concrete – these are the carbon emissions involved in the production of the material, transportation to the site and use in construction.
Jankovic and his team at Zero Carbon Lab, a center that works with government, local authorities and industry, estimated that the brick embodies emissions of about 357 kg of CO.2 per cubic meter, while a concrete cube is about 10 times higher.
“Although these embodied emissions are not always taken into account, they all enter the atmosphere and complicate climate change control,” says Jankovic. He argues that by 2050 it will take a long time to reach pure zero if these materials continue to be used without emissions, he says, even with the addition of renewable energy systems and energy-efficient upgrades.
But there is another low-carbon option. Jankovic’s study shows that using materials from biological sources that can reduce initial emissions, such as hemp or hemp lime instead of brick, could help reach pure zero by 2045 in new buildings along with other zero-value design strategies. In his view, new research is needed to update background information on embodied emissions in other materials from biological sources, such as straw, wood and others, that “sequester” carbon from the atmosphere during plant growth. This information is currently not available to designers.
In collaboration with Welwyn Hatfield City Council in Hertfordshire, Jankovic’s research into zero-carbon buildings is helping the authorities reduce the cost of building renewable energy, improve insulation and choose more environmentally friendly building materials. It also helps the Stevenage District Council assess how best to reach pure zero by 2030.
Using advanced simulations and dynamic heat transfer simulations, Jankovic and his team can calculate building emissions over a period of time based on hourly weather data collected for the year – 8,760 datasets, while simplified methods based on 12 monthly averages data sets and stationary heat transfer gave much less accurate results. This larger amount of data makes a difference by allowing for more rigorous analysis. “We need to quantify everything from initial emissions to current emissions, and“ clicking and poking ”these computer models in a structured way helps us determine how we get to zero,” he says.
Jankovic is working to make these techniques available to councils and local authorities so they can use pre-set projects to achieve pure zero with greater confidence. Ultimately, changes occur at the design stage before new construction or upgrades.
“Everyone needs to understand what it means to design zero-emission buildings – there are currently not enough people in the industry who are qualified to design zero-emission based on rigorously tested performance data,” he says. “But if we really want to get serious about achieving pure zero, we need to improve skills across the industry and unite everyone, from developers to builders, to planners, architects and models, to create a critical mass of new professionals capable of designing and delivering buildings with confidence in performance results ”.
Learn more about Herts ’multidisciplinary research that is changing the game, about how they deepen the understanding of climate change and help combat environmental emergencies.