Retrofitting older buildings with commercial heat pumps isn’t just about swapping out an old boiler for a sleek new system. If only it were that simple. The reality is that many older properties whether office buildings, retail spaces, or listed heritage sites were never designed for modern heating technology.
But with soaring energy prices, tighter regulations, and the UK’s push towards net zero, heat pumps are becoming an increasingly attractive option for facility managers. The challenge? Making them work in buildings that weren’t built with energy efficiency in mind.
If you’re considering a heat pump retrofit, you need to navigate insulation issues, space constraints, planning permissions, and system compatibility. In this guide, we’ll walk through the key challenges, practical solutions, and real-world case studies to help you decide whether a heat pump is the right move for your building.
Why Retrofitting Older Buildings with Heat Pumps Is Worth Considering
Heat pumps work by transferring heat rather than generating it. This makes them much more efficient than gas or oil-based systems. Instead of burning fuel, they extract heat from the air (Air Source Heat Pumps, or ASHPs) or the ground (Ground Source Heat Pumps, or GSHPs).
For older buildings, this efficiency is appealing, but the reality is that heat pumps work best in well-insulated properties. A draughty Victorian warehouse or a solid-walled Edwardian office block may need some upgrades before a heat pump can perform at its best.
The good news? Heat pumps can be adapted to work with existing heating infrastructure—though it often requires some tweaking.
Key Challenges When Retrofitting a Heat Pump
1. Insulation & Heat Retention
The number one issue with older buildings is heat loss. Unlike gas boilers, which can quickly blast out high-temperature heat, heat pumps work best at lower temperatures over longer periods. That means if a building is leaking heat through uninsulated walls, single-glazed windows, or draughty gaps, the heat pump won’t be able to keep up.
What to check before installing a heat pump:
Does the building have solid brick or stone walls? If so, you may need internal or external insulation. Are the windows single glazed? Secondary glazing or draught-proofing can make a big difference. Are there air leaks around doors and window frames? Sealing these can improve efficiency.
For listed buildings or those in conservation areas, insulation upgrades may be restricted. In such cases, hybrid systems (where a heat pump works alongside a backup boiler) could be a more practical solution.
2. Space Constraints
Older buildings were never designed to accommodate modern heating systems, so finding the space for a heat pump unit can be tricky.
- Air source heat pumps require external space for the outdoor unit. In city centres or densely built areas, this can be a challenge.
- Ground source heat pumps need trenches or boreholes, which require a decent amount of land—something most commercial buildings don’t have.
For properties without the necessary space, solutions include:
Compact air source heat pump units that can be installed on flat rooftops or courtyards. Shared ground loop systems, where multiple buildings tap into a central ground source heat pump system.
3. Noise & Aesthetic Concerns
In urban environments, noise can be a sticking point. While heat pumps are much quieter than traditional boilers, they do produce some sound—especially the external unit of an ASHP, which runs a fan.
- Some councils have strict noise regulations, so it’s worth checking planning rules before installation.
- In heritage buildings, visual impact is also a concern. Positioning units out of sight or using acoustic barriers can help mitigate these issues.
4. Compatibility with Existing Heating Systems
One of the biggest misconceptions about heat pumps is that they can simply be slotted into place. In reality, most older buildings have high-temperature heating systems designed for gas or oil boilers. Since heat pumps run at lower temperatures, they might not work efficiently with existing radiators or pipework.
Potential solutions:
Upgrade to low-temperature radiators, which have a larger surface area for better heat distribution. Consider underfloor heating, which is highly efficient with heat pumps (though expensive to retrofit). Use a hybrid system, keeping a backup boiler for very cold days when extra heat is needed.
Case Studies: Successful Heat Pump Retrofits
Sutton Dwellings, Chelsea
A historic Edwardian-era social housing block successfully retrofitted with ground source heat pumps. Engineers drilled 27 boreholes and installed compact heat pumps in each flat, reducing residents’ heating bills while significantly lowering carbon emissions.
Source: The Guardian
Greenhouse, Leeds
Originally an industrial building, this property was transformed into an eco-friendly residential complex with solar panels and ground source heating. The retrofit slashed energy use by over 40%, proving that even older buildings can achieve modern sustainability standards. Source: Financial Times
Cost & Funding Considerations
Upfront Costs vs. Long-Term Savings
Heat pump retrofits don’t come cheap. The typical cost for an air source heat pump in a commercial setting ranges from £15,000 to £30,000, while ground source systems can be significantly more.
However, the long-term energy savings make it a worthwhile investment.
A 1960s office retrofit with an ASHP saw a 30% drop in heating bills within two years. Source: The Times
Government Incentives
To help with costs, the UK government offers financial support:
Boiler Upgrade Scheme (BUS) – Grants of up to £7,500 for heat pump installations. Salix Energy Efficiency Loan Scheme – Interest-free loans for public sector buildings.
Taking advantage of these schemes can significantly reduce upfront costs.
Regulatory & Planning Permissions
If your building is listed or in a conservation area, planning permission will likely be required. Even if it’s not, you may still need approval if the heat pump exceeds noise thresholds or impacts the building’s appearance.
Source: Gov.uk
Best Practices for Facility Managers
Start with an energy audit – Identify insulation or efficiency upgrades needed before installing a heat pump. Work with experienced contractors – Retrofitting older buildings requires specialists who understand system compatibility issues. Consider a phased approach – A hybrid heat pump system can help ease the transition if a full retrofit isn’t feasible. Monitor performance post-installation – Smart meters can help fine-tune system settings for maximum efficiency.
Final ThoughtsRetrofitting an older building with a heat pump takes careful planning, but the benefits are undeniable. Lower energy bills, reduced carbon emissions, and future-proofed compliance with government regulations make it a smart investment for facility managers.