Global emissions of carbon dioxide, a major greenhouse gas and driver of climate change, increased from 22.4 billion metric tons in 1990 to 35.8 billion in 2013, a rise of 60 percent. The increase in CO2 emissions and other greenhouse gases has contributed to a rise of about 0.8 degrees Celsius in mean global temperature above pre-industrial times.
Excerpt, March 2021, https://www.euractiv.com/section/energy-environment/news/eco-homes-become-hot-property-in-uks-zero-carbon-paradigm-shift/
after scrapping Labour’s zero-carbon homes target in 2015, the Conservative government has finally developed a future homes standard, which will mandate all new homes to be “zero-carbon-ready” – although not until 2025 at the earliest.
So it has been the landlords with a long-term interest in the wellbeing of their tenants, and the longevity of their building stock, who are forging ahead with low-energy housing. Exeter city council, for example, has been quietly building zero-carbon homes for the last decade, with more than 200 council houses built so far to the exacting Passivhaus low-energy standard, and 1,000 more in the pipeline.
“We were originally driven by trying to address fuel poverty,” says Emma Osmundsen, director of the council’s housing company, Exeter City Living. “Not many people were talking about climate change in 2009, when we built our first three Passivhaus homes, so we became a kind of accidental pioneer.” The council is now on the seventh generation of its low-energy house design, which it has honed over the years to make it as “idiot-proof” as possible, says Osmundsen. Rather than timber frame, they use clay blocks that slot together like Lego bricks and contain a honeycomb of air pockets, negating the need for additional insulation. The homes are so thermally efficient that 60% of the tenants haven’t had to switch on their heating at all – some for more than 12 years.
Like many in the industry, she thinks the biggest barrier to wider adoption of low-energy standards is the lack of care and attention to detail on British building sites. “Passivhaus is really not complicated, and it doesn’t have to cost more than conventional construction,” she says. “It’s a bit like baking a cake: most of the ingredients are the same as a regular house, but you just have to follow the recipe in the right order. Perhaps it’s because the building industry is so male-dominated, but there is a general reluctance to follow the recipe.”
Many other councils are following Exeter’s lead. Norwich completed the country’s largest Passivhaus social housing scheme in 2019, winning the prestigious RIBA Stirling Prize in the process, while York is planning an even more ambitious scheme by the same architects, Mikhail Riches. Cardiff University built an “energy positive” solar house in 2015, using low-cost, off-the-peg materials, with features that have since been replicated in more than 1,400 affordable and low-carbon houses across Wales. Oxford has started work on its first zero-carbon council homes, while Enfield council’s huge £6bn Meridian Water development is also targeting net zero.
“It used to feel like we were ploughing a lone furrow,” says Jon Bootland, the chief executive of the Passivhaus Trust, which was established over a decade ago to promote the low-energy standard, but for years was seen as the preserve of one-off eco-homes in the countryside. “Now our approach is really in the mainstream, as one of the few proven routes to net zero.” The non-profit organisation, which trains designers and contractors and certifies buildings, has recorded a 60% increase in membership over the last year alone.
The environmental engineer Clara Bagenal George, the founder of the London Energy Transformation Initiative (Leti), has calculated that there are now about 30,000 homes at the masterplan stage that meet the Passivhaus target for a space heating demand of just 15 kWh/sq metre/year (compared with the current average of 54 kWh/sq metre/year), equating to a massive reduction in carbon. “It’s an amazing story,” she says. “The industry defined ‘good’, over and above the regulations, and within a year there are now tens of thousands of homes in the works that meet this standard. It shows we can do it.”
And even the volume housebuilders are starting to get onboard. “It’s almost paradigm shift territory,” says Simon Usher, divisional director of Persimmon Homes, one of the largest developers in the country, which infamously paid its former chief executive a £75m bonus in 2018, while its homes were found to be riddled with construction defects. In 2019 the company admitted it had lobbied the government to axe its zero-carbon policy, but, in an effort to clean up its image, with a new chief executive at the helm, it is now working on a prototype zero-carbon house of its own near its headquarters in York.
“It’s an unashamedly normal house,” says Usher. “We wanted to see how far we could get with our standard masonry construction, building with our usual concrete bricks and tiles, but adding more insulation, beefing up the windows a bit, and adding an air-source heat pump in the garden. In the end, we got to zero carbon, for about 15% additional cost.”
“People are willing to pay more for an electric car to do the right thing,” says Usher. “Will they be willing to do the same for a zero-carbon home? The market will decide.”
Mahlum Architects’ New Office is the First Living Building–Certified Project in Portland. The Custom Blocks complex in Portland, Oregon’s Central Eastside Industrial District has become the city’s first Living Building Challenge (LBC)–certified project. Owned and occupied for more than half a century by a machine parts fabricator, the two-block cluster of warehouses was soaked in oil and grime. Yet after developer Capstone Partners commissioned a 2018 core-and-shell renovation to clean up and seismically bolster the structures, they proved ideal for a sustainable regeneration. Mahlum Architects moved its Portland office to the Custom Blocks in November 2019. By following rigorous LBC guidelines, the group has turned the location into a model of its organizational values, including sustainable design. The LBC comprises seven performance categories, or “Petals”: Materials, Place, Water, Energy, Health, Equity, and Beauty. Buildings achieving full Living Building status, like Seattle’s Bullitt Center, meet standards in all seven areas. Metropolis, August 14, 2021, https:// www.metropolismag.com/sustainability/mahlum-architects-new-office/