Swapping out an old boiler for a modern heating system might seem straightforward on paper. But in reality, especially when dealing with older buildings, it rarely is. Whether it’s a Georgian townhouse, an Edwardian shopfront, or a listed gem with architectural quirks, heat pumps weren’t exactly top of mind when these places were built.
Still, with energy bills climbing, sustainability targets tightening, and net zero deadlines looming, a Commercial Air Source Heat Pump is no longer a pipe dream. The challenge is making it work in buildings that were never designed with energy efficiency in mind.
If you’re considering a retrofit, there’s a bit of a learning curve. From draughty walls and planning hurdles to cramped layouts and vintage heating systems, there’s plenty to factor in. This guide lays out the key challenges, practical solutions, and a few real world examples to help you decide whether a heat pump could work for your building.
Why Heat Pumps Make Sense for Older Properties
Heat pumps don’t generate heat the way a boiler does. They move it. They pull warmth from the air or ground and transfer it indoors, making them far more energy efficient than their gas or oil burning cousins.
That makes them an attractive option for older buildings. The catch is they perform best in well insulated spaces. So if your site still has single glazing or uninsulated brickwork, you’ll need to tackle those weak spots first to really benefit.
It’s not necessarily easy, but it is doable. With the right groundwork, even buildings from another era can be brought up to speed.
Key Challenges (And What You Can Do About Them)
1. Poor Insulation and Heat Loss
Let’s not sugar coat it. Older buildings bleed heat. Unlike boilers that give off intense bursts of warmth, heat pumps operate steadily at lower temperatures. If your building leaks heat through every crevice, you’ll be fighting a losing battle.
What to check:
- Walls — Solid brick or stone may need internal or external insulation upgrades
- Windows — Still stuck with single glazing? Secondary glazing or draught proofing can make a noticeable difference
- Air gaps — Check around doors, floorboards, and windows. Seal what you can
For listed buildings or those in conservation zones, a full upgrade might not be on the table. In those cases, a hybrid approach using a heat pump paired with a boiler can give you flexibility.
2. Limited Space
Heat pumps aren’t small, and older buildings often don’t have room to spare.
- Air Source Heat Pumps need external units, which can be awkward in city centre locations
- Ground Source Heat Pumps require trenches or boreholes, making them a tough sell on built up sites
Workarounds to explore:
- Compact air source units that can be roof mounted or tucked away in courtyards
- Shared ground loop systems for multi building campuses
3. Noise and Aesthetics
Heat pumps are quieter than traditional systems but not silent. Outdoor air source units do produce a low hum, which can be an issue in residential or densely populated areas.
Keep in mind:
- Local councils may enforce noise limits. Always check the regs
- For heritage sites, appearance matters. Acoustic housing and clever placement can help avoid both noise complaints and aesthetic objections
4. Legacy Systems That Aren’t Compatible
It’s a common misconception that you can just plug a heat pump into an old heating setup and expect it to perform. Traditional systems are built around high temperature heating. Heat pumps aren’t.
To get the best results, you might need to:
- Upgrade to larger radiators that suit lower flow temperatures
- Install underfloor heating, though retrofitting this can be pricey
- Consider a hybrid setup that uses the boiler during colder months
Examples in the Wild
Sutton Dwellings, Chelsea
This Edwardian social housing block had 27 boreholes drilled to support a ground source heat pump system. Compact units were installed in each flat, cutting both emissions and energy bills
📖 Source: The Guardian
Greenhouse, Leeds
Once a disused industrial building, now a green residential complex. It uses ground source heating and solar panels, cutting energy use by over 40 percent
📖 Source: Financial Times
Budgeting and Support
Upfront Costs vs Long Term Gains
Let’s be clear. These systems aren’t cheap. A typical air source heat pump install might set you back £15,000 to £30,000. Ground source options usually cost more. But the savings add up over time.
Case in point. A 1960s office block retrofitted with an ASHP saw its heating bills drop by nearly 30 percent in just two years
📖 Source: The Times
Financial Assistance
There’s help out there:
- Boiler Upgrade Scheme (BUS) offers grants up to £7,500
- Salix Scheme provides interest free loans for the public sector
Used wisely, these schemes can ease the financial pressure.
Planning and Permissions
If your building is listed or in a conservation area, you’ll almost certainly need permission. Even if it’s not, installations that affect how the building looks or that generate significant noise could still need approval
📖 Source: Gov.uk
Getting It Right: Tips for a Smooth Retrofit
- Start with an energy audit to identify problem areas before committing
- Hire experienced contractors who understand the quirks of older buildings
- Consider a phased rollout using a hybrid system to ease the transition
- Track performance with smart controls and monitoring tools for ongoing optimisation
Final Word
Retrofitting a heat pump into an older building is no quick fix, but it’s far from impossible. With smart planning and the right team, it’s entirely achievable.
And the payoff? Lower bills, a lighter carbon footprint, and a building fit for a net zero future.
For facility managers looking beyond short term savings, it’s a smart investment in sustainability and resilience.
