With the upcoming 26th United Nations Climate Change Conference, or COP 26, world leaders will meet in Glasgow to discuss the climate emergency and ways to achieve net-zero targets.
Building industry emissions
In 2020, the UN reported that global building sector emissions had reached a record high, making up 38% of energy-related carbon emissions. Within Europe, the heating of buildings accounts for around one-third of energy use.
In the UK context, one area that requires urgent attention is residential housing stock. Indeed, according to the Climate Change Committee, 18% of the UK’s building emissions have been attributed to residential homes. The UK has some of the oldest and least energy-efficient houses in Europe, with around 40% of housing stock built before 1945. Critically, an estimated 80% of the UK’s 27 million existing dwellings will still exist in 2050. The poor energy efficiency of our homes has implications not only when planning to meet climate goals but also on the health and comfort of people living in them. Therefore, improving the efficiency of these buildings it both environmentally and socially important.
Putting words into action
Building according to Passivhaus regulations would contribute towards these goals. The advantages of living in a Passivhaus include reduced heating and cooling demand, a constant, comfortable temperature, and no chance of mould – thus ensuring exceptional indoor air quality. This equates to reduced energy demands and carbon emissions, as well as a higher quality living environment for residents.
But what about all the existing properties not build according to these standards? Demolition and rebuild? One alternative and typically less expensive solution is to carry out a ‘deep retrofit’ of poorly insulated existing buildings to improve the fabric and reduce heat loss. Carrying out a deep retrofit creates far fewer emissions than produced through demolition and rebuild. This is no easy task – figures published by thePassivhaus Trust suggest that a retrofit would have to take place every 35 seconds if we are to meet 2050 goals.
The London Energy Transformation Initiative (LETI) has published a report outlining how retrofitting be put into action. A variety of approaches have been put forward, including the Passivhaus retrofit certification EnerPHit. EnerPHit is considered a valuable approach as an independent certification that allows for more flexibility while maintaining high standards. Perhaps the most realistic proposal is the EnerPHit step-by-step method. This method allows for gradual implementation of retrofit measures, although a full plan and overview of the project are necessary before beginning. Examples of retrofit strategies include super insulation, thermal bridging; fenestration; air tightness; heat recovery ventilation; and space heating. However, there are associated challenges that need to be overcome.
The next few weeks mark an important time as several talks will take place to discuss how best to improve the energy efficiency of UK housing.