With tighter energy efficiency targets in place and a broader UK commitment to 2050 net zero, selecting the best roadmap to low-carbon heat can feel daunting for social housing providers. Rob Pearse, Residential Business Director at Baxi, outlines some of the options
The clock is ticking for social housing providers who have been targeted with meeting an Energy Performance Certificate (EPC) rating of Band C or higher by 2030. The good news, as revealed by the English Housing Survey, is that the proportion of social sector homes in the highest energy efficiency bands A to C has risen from 23% to 52% in the last decade. The target now is to retrofit this social housing stock to net zero, supporting the UK’s broader climate goals while improving comfort levels for tenants and protecting them from fuel poverty.
Transitioning to low-carbon heating solutions like heat pumps and heat networks is key to meeting net zero. To date, social housing providers have prioritised light retrofit to improve building fabric. This positive early step will help them to plan for the next deeper retrofit phase: decarbonising heat. Let’s consider the options.
Heat pumps
The UK Government favours electric heat pumps as one of the most efficient technologies for decarbonising heat in homes, and rightly so, as heat pumps can be up to four times more efficient than a boiler in terms of energy use, although not so for running costs. New build social housing will be designed from the bottom up to be heated by low-temperature heat pumps. However, retrofitting heat pumps into existing homes, while absolutely possible, can be more complex.
Lack of space is a common constraint. In standard two-up, two-down social homes that currently rely on combi boilers for their heating and hot water, finding an indoor location for a hot water cylinder can be challenging.
A shortage of technical skills can also deter social housing providers from making the switch. Retrofitting heat pumps is more involved than a simple boiler upgrade, requiring greater skill and knowledge to ensure high heat performance. Added to which, the greater time required for a heat pump installation can result in increased disruption to tenants.
Finally, avoiding fuel poverty is a major concern for social housing providers as many of their tenants are on low incomes. With electricity costs currently around four times that of gas, the spark gap can discourage many from moving to a fully electric system. So, in homes where social providers may struggle to install an all-electric heat pump solution, what alternative options are available to make it easier to decarbonise their properties?
Hybrid approach
One achievable option might be to take a hybrid approach. Combining an air source heat pump with a combi boiler would overcome the cylinder space issue, as the heat pump would provide the heating, while the combi would be retained for peak winter heating and hot water.
In harder-to-treat properties, a hybrid solution would be more affordable and take up less space. Installation is faster, simpler, and less disruptive, as fewer changes, if any, would be required to the pipework or radiators.
Importantly, from an emissions perspective, retrofitting a heat pump into the existing system can decarbonise a significant portion of the building’s heat requirement while increasing system resilience. Indeed, case studies from the European Union prove that the heat pump in a hybrid system can provide as much as 80% of the annual space heating requirement. Given the importance of funding to tackling social housing retrofit, we hope to see hybrid solutions fully included in government funding schemes in the near future.
Modular pods
Where an all-electric approach is the favoured route, what options are available to overcome space restrictions?
Here, it may be worth considering modular solutions. Using highly efficient modern methods of construction, prefabrication specialists like Baxi Packaged Solutions can manufacture factory-built, customised turnkey pods that contain the heat pump system. These can then be bolted onto a house as a porch, a recycling shed, or a bicycle shed.
In this way, modular configurations provide an excellent opportunity to ensure a simpler installation, reducing on-site labour and time while creating more indoor space for the tenant. As manufacturing costs lower with economies of scale, modular solutions can offer an important opportunity to scale up decarbonisation across the social housing portfolio, delivering big wins.
Heat networks
Communal heat networks, also known as district heating, are another efficient and cost-effective means of heating multi-occupancy buildings such as high-rise tower blocks and low-level residential housing in dense urban areas. The heat source is a centralised energy centre that transfers the heat to each property through insulated underground pipework, minimising heat loss. A Heat Interface Unit (HIU) transfers the heat into the individual properties to provide heating and hot water without the need for a boiler in each home.
New regulatory technical requirements are being introduced for both legacy and new heat networks to achieve minimum technical standards. When upgrading the energy centre, consider using prefabrication specialists to manufacture a packaged energy centre. Whether fully electric or hybrid systems, the pre-assembled energy centre can be dropped into the required location in sections or as a single lift, depending upon the size or site requirement.
When replacing existing HIUs, look for BESA V3 2023 certified models that lead the market in terms of performance and heat loss reduction. Baxi’s AquaHeat Direct and Indirect HIUs are suitable for use in both low-rise and high-rise apartments and communal heat networks. They can also be used in conjunction with heat meters and our own Mercurius connected platform for remote monitoring, control and remote fault diagnostics.
Manufacturer support
It’s clear that, given the pressure on budgets, the next wave of funding will be instrumental in helping social housing providers accelerate heat decarbonisation in their housing stock. At the time of writing, we await with interest the full details of the broader Warm Homes Plan, which is due to be announced later this year.
And with no silver bullet available, we at Baxi look forward to working with social housing providers to help them arrive at the best solution for their building types, as well as educating their tenants on living with the new system.
For more information, visit www.baxi.co.uk/professional/specifiers-and-social-housing
This work is licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International.
