The Insulation Manfacturers Association offers advice to local authorities and housing associations on meeting decarbonisation targets through retrofitting.
Heating our homes contributes around 17% of the total UK carbon emissions, which is why retrofitting housing is a crucial part of our mammoth task towards the net zero 2050 target. Many buildings in the UK are simply not up to the high energy efficiency standards necessary and as a result, it is widely accepted that the UK must embark upon a comprehensive retrofit programme of the existing housing stock if it is to achieve net zero carbon by 2050, as well as the other stated targets expected to be achieved along the way.
In general, homes in the UK are considerably older than elsewhere in Europe, with 5.8 million built before 1919 and more than half built before the initial insulation requirements were introduced to the Building Regulations in 1965. As a result, many homes lose heat through poor and inefficient building fabric, which encompasses a wide variety of construction methods and materials. Many homes are also in poor and varying states of repair, so as a result, there is no simple, one-size-fits-all solution to retrofit the housing stock.
Part L updates
Updates to Part L of the Building Regulations for England have recently been published, outlining the new standards required for energy efficiency of buildings in England from 15th June 2022 (Scottish and Welsh new energy efficiency updates will also follow later this year). From 2025, all new homes and other buildings are expected to be ‘net zero ready’, which means they will need to be built to ultra-high levels of energy efficiency with heating demand similar to that of the Passivhaus Standard (15-20 kWh/m2/year). Unfortunately however, there is little in the latest update for improvements to existing buildings.
The Government is expecting the energy performance of existing homes to be upgraded by 2035, with all homes raised to an Energy Performance Certificate of at least C where “practical, affordable and cost effective”. This will require more than 15 million homes in England alone, to be upgraded over the next 13 years.
Whilst the recently published Heat and Building Strategy expands on the detail of heat in buildings, there is rather less on improving energy efficiency, reducing demand or the essential policy needed to support any large scale approach to mass retrofitting.
Low carbon approach
If we are to move to a net zero carbon country by 2050 (2045 in Scotland), it will be vital to make improvements to homes and other buildings to reduce emissions. This means installing a whole range of energy saving measures; from new insulation and more efficient appliances, to replacing fossil fuelled boilers with low carbon alternatives, such as heat pumps.
There are probably two key issues in moving to decarbonised heating (although these do not provide the whole answer). The first is the cost of fuel, especially if demand is not reduced alongside decarbonised heating. If demand is high, heating costs for consumers will rise massively compared to current heating costs. Secondly, available national energy generation to service overall demand is lacking, especially if both transport and space heating for buildings are converted to electric, requiring an enormous increase of electrical generation. Reducing heating demand in buildings will mean less generation is needed. This therefore should become an infrastructure issue as well as a climate change issue.
If we do not reduce demand, the incidences of fuel poverty will increase; if there is inadequate generation to service demand, decarbonisation could stall if less clean generation approaches are needed to service higher demand. Developing additional generation with additional power stations could also lead to rising fuel costs, increasing fuel poverty levels still further, unless heat demand is also reduced.
For the equation to work it would require a reduction of energy demand, an increase in clean generation and the installation of heat pumps at a similar cost to fossil fuel boilers.
In addition to helping tackle climate change, energy retrofit work also means that homes will require less energy for heating and power. This can help to reduce energy bills and even help lift families out of fuel poverty, whilst significantly improving comfort and wellbeing and contributing to energy security.
When improving an existing building, the improvement package really needs to be designed around each specific house. Factors such as the building’s design, location and the constructions used for the walls, floor and roof will impact the best solution; ensuring correct detailing, using the most appropriate materials in the correct way and in the optimum place are all important considerations. Before any installation is undertaken, other issues may need to be addressed, including the need for adequate building ventilation, especially if work is to make the building more airtight.
Competency in installation
Given these complexities, it is advised to work with a retrofit coordinator and carry out the improvements to PAS 2035:2019. This is a public specification which sets out a clear process for assessing a home, dealing with any issues and developing a medium-term improvement plan which sets out the best order for installing the improvements. Installation and commissioning needs to be carried out to a good standard via a competent and trained installer — for example to PAS 2030:2019 and via a TrustMark Registered company.
Insulation strategy
Suitable for anyone looking to learn about the application of low carbon strategies through a fabric first approach, Insulation for Sustainability, highlights the issues associated with energy demand and the way enhanced insulation strategies play a crucial role in the built environment helping the UK meet its net zero targets.
Retrofitting insulation works for a whole host of reasons, from saving money to carbon reduction. Whether using internal or external insulation, it is vitally important the UK’s housing stock is raised to an acceptable standard by making the fabric of the building as energy-efficient as possible. Only then will we be able to provide a long-term asset that reduces energy usage and can be confidently passed on to future generations.