Do Heat Pumps Work in Old Houses?

A case study from a 600-year-old listed home in Hampshire

If you live in an older property, you might be wondering: Can heat pumps really work in old houses? You’re not alone - it’s one of the questions we hear most often.

Our team recently worked on a beautiful 600-year-old timber-framed home in Hampshire, and it’s living proof that yes, heat pumps can absolutely work in old houses - with the right approach.

The Home: A Heritage Beauty with Modern Ambitions

This Grade II listed property has all the charm (and challenges) you’d expect: single-glazed windows, no insulation, and original timber framing.

The homeowner wanted to move away from fossil fuels and make the switch to renewable heating, but understandably didn’t want to compromise the heritage of the building. The big question was - could a heat pump really keep such an old home warm and comfortable?

The Challenge: Understanding How Much Heat the House Actually Loses

Traditional heat loss calculations use estimates of what the building is made of, but in a house of this age, this really is guess work.

Rather than relying only on theory, we partnered with Purrmetrix to monitor the home’s real-world performance during the coldest month of winter. Small data loggers were placed around the property to record room temperatures and heating patterns over a period of 4 weeks. This method doesn't just look at how much heat the property loses through its walls, windows, roofs, but also how draughty the property is, because this has a huge impact on overall heat loss.

The results were reassuring, it validated that our standard MCS heat loss methodology was sound, but on the cautious side, so we could fit a single 16kW heat pump in full confidence that it will keep this house warm inside no matter whatever the weather outside.

The Solution: Making a Modern Heat Pump Work in an Old House

We installed a Samsung 16kW R290 Monobloc heat pump, paired with a custom open-vented hot water cylinder that worked perfectly with the home’s traditional gravity-fed plumbing system.

Every radiator was replaced with modern, high-efficiency models:

• Triple-panel radiators for the largest rooms

• Double-panel radiators for smaller spaces

• New thermostatic valves and lockshields throughout

  
  

To make life easier, the homeowner now manages everything via a Homely smart thermostat, allowing them to tweak settings and benefit from time-of-use electricity tariffs -helping lower running costs even further.

The Reality: Installing a Heat Pump in a 600-Year-Old Home

We won’t sugar-coat it - installing heat pumps in old houses can be disruptive. Floors need lifting, pipework gets upgraded, and radiators are replaced. Some redecoration is often part of the journey.

But, as with all our projects, the team worked carefully with the homeowner, checking radiator positions and tidying up at the end of each day. The respect shown for the historic property was as important as the technical design.

The result? A warm home, a happy customer, and centuries of character perfectly preserved.

The Results: Comfort, Savings, and Sustainability

• The home is now heated entirely by renewable electricity.

• The system is optimised for real-world performance, avoiding oversizing and unnecessary cost.

• Even with single glazing and no added insulation, the house is comfortably warm.

• The homeowner received a £7,500 Boiler Upgrade Scheme grant, helping offset installation costs.

Lessons Learned: How Heat Pumps Work in Old Houses

This project answers the question “Do heat pumps work in old houses?” with a resounding yes—but with caveats:

• Measurement matters. Data logging can refine estimates and give confidence in system design.

• Radiator upgrades are key. They make comfort possible at lower water temperatures.

• Expect some disruption. It’s part of the process, but worth it.

• Don’t dismiss old homes. Even in heritage buildings with minimal insulation, a heat pump can provide reliable, low-carbon heating.

Thinking About a Heat Pump for Your Period Property?

If you love your old home but want to cut your carbon footprint and reduce your reliance on oil or gas, it’s absolutely possible.

Your home’s age doesn’t have to hold you back. It just needs the right design, careful planning, and a team who understands both technology and heritage.

Ready to find out what’s possible for your home? Book a Discovery call or complete our online project questionnaire here.

Frequently Asked Questions About Heat Pumps in Old Houses

1. Do heat pumps really work in old houses?

Yes, absolutely. Even in older or listed properties, heat pumps can work brilliantly when designed correctly. The key is to understand your home’s actual heat loss and ensure your radiators and system are properly sized. Many homeowners are surprised at how comfortable and efficient their homes feel once the system is up and running.

2. Will I need to insulate my old house before installing a heat pump?

Good insulation always helps improve efficiency, but it’s not a deal breaker. Many old houses without modern insulation can still benefit from a heat pump. A detailed heat loss assessment will help determine what’s needed - sometimes simple upgrades like draught-proofing or better radiator sizing make a big difference.

3. Is it expensive to install a heat pump in an old property?

Costs vary depending on the size and layout of your home, but government grants such as the Boiler Upgrade Scheme (£7,500) can significantly reduce upfront costs.

With regards to running costs, heat pump tariffs offer lower electricity rates for households with heat pumps. Providers like OVO, Octopus and ScottishPower, offer special pricing during off-peak hours. These tariffs often require a smart meter and allow you to heat your home more cheaply by shifting usage to cheaper periods.

4. How disruptive is the installation process?

There will be some disruption - floors may need to be lifted, new pipework and radiators installed, and redecoration afterwards. However, a skilled installer will plan carefully, protect your home’s features, and keep disruption to a minimum.

5. Are heat pumps suitable for listed buildings?

Yes, they can be. Every listed property is unique, but with the right permissions and design approach, heat pumps in listed and heritage homes are increasingly common. Working with an experienced installer familiar with heritage properties is key to protecting the building while delivering modern comfort.