There are some key ‘heat pump readiness’ changes to homes that require homeowners' active involvement. We want to make these easier to do in advance, or more routine, to take away some cost and effort from the actual moment of installing a heat pump.

2a. Incentivise low-temperature systems

Heating engineers often describe the transition to a heat pump as two-fold: first to a low flow temperature system (larger radiators and pipework) and then to a new heating source. Ensuring a home is fit for a low-temperature system makes a later heat pump installation smoother.

Key touchpoints could be used to move households onto low temperature systems (systems with radiators and pipework suitable for 55 degree flow temperature or below).

Boiler maintenance and repair. When a heating engineer is at a property, homeowners have an opportunity to learn about heating options and how to optimise their heating system. Some heating engineers already advise people to lower their flow temperature, install weather compensation or start thinking about radiator upgrades. However, due to the high number of individual engineers, it is difficult to influence the advice they give. Many gas engineers report not having the time or incentives to provide advice about heat pumps and low-temperature systems during routine appointments with households. However, we believe there is an opportunity here for vertically integrated companies that both install heat pumps and provide boiler servicing.

New boiler installations. If all new boiler installations were to include a transition to low flow temperatures, every installer would need to do a full heat loss calculation and fit new radiators if needed. As a result, over a million households every year would become one step more ready for a heat pump.

The additional work would add significant costs to new boiler installations. We could assume that about 7 out of 10 properties would need larger radiators to operate at lower flow temperatures, and they would replace 6 radiators on average (assumptions based on a 2020 survey of installers). If each radiator costs £200, the average price across all households would be £840. If each heat loss calculation costs around £250, the whole process would add almost £1,100 to the average boiler installation. At 1.7 million boiler installations per year, the total cost could be around £1.9 billion.

Part L of the building regulations for England already mandates all new heating systems to be designed to a maximum temperature of 55 °C. Extending the mandate to all changes to heating, including new boilers, would most likely require regulatory oversight and enforcement by the Gas Safe Register. Such a mandate would come with many challenges. The high cost compared to simple boiler replacements, if placed on consumers, would likely face significant resistance, especially since energy savings from more efficient gas systems tend to be small.

Low-flow temperature design could be mandated for all publicly funded retrofits (primarily through schemes like ECO). But it is difficult to justify a situation in which households eligible for free upgrades receive only marginal improvements to their heating systems, rather than progressing directly to the installation of a heat pump.

Making changes to the heating system for practical or aesthetic reasons. Another way to promote earlier radiator upgrades could be to introduce incentives for people renovating their homes. Radiators are currently zero-rated in terms of VAT if installed alongside a heat pump. This rule could be extended to all radiators installed as part of a low-temperature heating system, incentivising renovators to opt for adequately sized radiators.

The UK market for residential radiators is estimated at £252 million. If, for example, 10% were eligible, subsidising them at 20% (VAT) would add up to government cost of £25 million/year. However, the zero rate would be difficult to implement since it would need to rely on builders’ or sellers’ declarations and would technically require a heat loss calculation to show precisely what emitter sizes are needed for a particular home.

We don’t currently see financial incentives or mandates for low flow temperatures as a practical route to heat pump readiness. The scale of enforcement required, the risk of fraud, and the added costs to households make this difficult to justify. There is also a real chance that these upgrades become less relevant as high-temperature heat pumps expand and radiator changes matter less. Overall, the returns look weak compared to directing support toward measures that help households move to a heat pump outright.

2b. Frontload electrical upgrades

Most installers subcontract electricians for upgrades to the home’s consumer unit, if needed as part of a heat pump installation. This adds time and cost.

These upgrades are possible to carry out in advance at points when there is already a qualified electrician in the home. For example, during a major renovation, when solar or batteries are being installed, or during repairs to lighting and appliances. The UK government could amend Part P of the Building Regulations (regulated separately for Wales and Scotland) to mandate that electricians check whether the home is ready for a low-carbon technology installation. If it is not, the electrician would need to inform the homeowner and offer to carry out the upgrade to the home’s electrics.

Another point where a homeowner engages with their electrical system is at a smart meter installation. Energy providers usually subcontract these to specialised smart meter installers. The easiest way for these to trigger electrical upgrades would be for the meter installer to do a simple visual inspection and report back whether an upgrade is necessary. The supplier could then coordinate with an electrician to do these electrical upgrades pre-emptively. Smart meter installations are sometimes the only point at which energy suppliers are in direct contact with their customers. Energy suppliers are likely to install a larger share of heat pumps in the future than they currently do. Some already own their own heat pump companies. As such, they are incentivised to build a pipeline of heat pump-ready customers who would be more likely to use them for a future heat pump or EV charger installation. Suppliers are already commonly installing isolation switches alongside smart meters where necessary.

Almost 250,000 smart meters are being installed each month (~3 million a year). If 20% of homes required a new consumer unit (no data available for this estimate), that would create 600,000 opportunities each year. With a 50% acceptance rate and if 80% of homes will need this to get a heat pump (CCC estimate), ~240,000 homes a year would become electrically heat-pump-ready through smart-meter visits.

Separately, there are ~3.5 million renovation projects each year, and surveys show ~60 % involve an electrician. Assuming the same rate of upgrades as above, this would yield more than 200,000 additional homes a year, becoming more ready.

Together, these touchpoints could deliver ~450,000 electrical upgrades per year, moving homes toward heat pump readiness. By shifting electrical upgrades to a time when an electrician is already on site, we estimate these homes would save £200–300 and 1–2 days on their heat pump installations.

However, we have heard anecdotally that many installers prefer to install an additional consumer unit when installing a heat pump, rather than upgrading the existing consumer unit. More work needs to be done to consider if encouraging upgrades to existing consumer units in advance of the heat pump installs is worthwhile, as it would be redundant if installers prefer to use additional ones.

2c. Nudge renovators towards heat pump readiness

Homeowners’ decisions affect their future heating options, often without them realising. The right advice, tools and incentives during or before renovations could make homes more ready for a heat pump. Below, we explore some promising touchpoints.

• Engaging an architect: People who hire architects are often already planning bigger changes and spending more. Focusing on architects’ continuing professional development, design checklists, or accreditation schemes could lead to more heat pump readiness. Home improvements could include always leaving space for a water cylinder, opting for larger radiators and designing for outdoor and indoor unit space.
• Working with consultants and builders: Mechanical and Electrical (M&E) consultants take practical decisions like pipe diameters and radiator sizes. A service could help them quickly assess whether a home’s systems are heat pump compatible, perhaps through a digital checklist. Builders could then recommend future-proof upgrades while floors or walls are already open.
• Shopping: Retailers influence thousands of small decisions every day – from which hot-water cylinder people buy to what advice they get in-store. Creating a ‘heat pump-ready’ product label or training staff to mention future compatibility could steer people towards future-proof choices.

Around 3.5 million households renovate their home each year (with £14,000 average spend). If only 1 in 20 of these added heat pump-ready changes to their projects, 175,000 more homes a year would become more ready.