“I’m spending far less on energy, spending far less on fuel for the car…I’m really happy with all the changes that we’ve made and they’ve paid off.”

What does a 1930s house retrofit look like?

When Alfie moved into a recently renovated 1930s semi-detached brick property, he soon found his new home had an inefficient, expensive heating setup. With an EPC rating of D, there was plenty of room to improve. 

Through a phased retrofit that incorporated solar PV with battery storage, an EV charger, and an Air Source Heat Pump, this lovely home now has an EPC rating of an A!

	Before Retrofit	After Retrofit
EPC Rating	D	A
Monthly Energy Costs	~£170/month (gas & electric)	~£70/month (includes EV charging)
Heating & Hot Water	Inefficient gas boiler & electric underfloor heating	Air Source Heat Pump (ASHP)
Gas Grid Status	Connected (paying standing charges)	Fully Disconnected (Zero standing charges)
EV Home Charging	N/A	~14p/kWh

The Challenge

When Alfie moved into the 1930s Kelvindale property, it looked great. The property had been modernised and even had a new extension. Upon moving in around Christmas however, their first energy bill was a bit of a shock. 

• Under-Sized Heat Emitters: Radiators were only installed downstairs and were undersized for the space. Existing electric underfloor heating upstairs was far too expensive to run.
• Some rooms were especially cold despite high heating spend.
• High Maintenance Costs: The aging gas boiler suffered frequent breakdowns, with quotes for replacement approaching £3,000* upfront.
• Maintenance: An aging roof required urgent repair.
  
  

“We were spending a lot of money on heating and it still wasn’t really very warm. In winter, I think we were roughly paying £170 a month.”

The Retrofit Strategy

The project followed a staged, logical approach to maximize investment efficiency, starting with structural repairs before moving to renewable energy generation and clean heating.

Over the course of the year, we generate about as much energy as we use. A year after the solar panels, we got a heat pump put in…we just got really fed up with living with an old boiler that needed fixing so much.

1. Roof Maintenance & Solar PV Installation

When a leaky roof required fixing, Alfie decided to also install rooftop solar panels and battery storage.

• On-Roof vs. In-Roof Solar: After evaluating options (including in-roof panels), they selected on-top roof panels due to their higher operational efficiency.
• Impact: Over the course of a year, the homeowners generate roughly as much electricity as the home consumes (Generating 4000kwh annually and consuming 5000kwh).
• DIY Loft Insulation: The owner personally rolled out loft insulation to improve the thermal comfort.

2. Thoughtful Heat Pump Design & A Great Installation

Rather than getting their boiler replaced, Alfie thought it would be best to take advantage of the grants and loans available for heat pump installation. Alfie also found that watching Heat Geek videos on Youtube was very helpful during the research process. 

• Design First: They chose a premium installation provider that prioritised detailed room-by-room heat loss calculations.
• Funding: The installation was fully financed using grant funding combined with an interest-free Home Energy Scotland loan (compared to around a £3000 for a new gas boiler installation).
• Gas Disconnection: The gas supply was capped and disconnected entirely, removing fixed daily gas standing charges.
• Prioritising great work: When choosing an installer, Alfie didn’t just choose the cheapest quote but rather went with an installer that impressed him from start to finish. 

3. EV Charging

• EV Charging: An EV home charger costs about 14p kilowatt hour. This is much cheaper compared to charging at a public travel charge point. (This doesn’t include any public charging costs, but Alfie rarely needs to do that.)

“I’ve gone from paying about £70 a month on petrol to about £28 a month on electricity…”

Operational Performance & Living Experience

Contrary to common heat pump myths, the upgrade significantly improved daily home comfort while lowering bills.

• Thermal Comfort: Constant, even warmth throughout the house without fluctuating temperatures or window condensation.
• Acoustic: The outdoor heat pump unit operates quietly. 
• Smart Integration: System controls integrate seamlessly via smartphone apps, supporting scheduling, vacation modes, and smart time-of-use tariffs.
• Hot Water Reliability: Replacing the combi boiler with a hot water cylinder provided consistent shower temperatures.

Financials & The New EPC

1. Energy Bill Reduction: Total energy costs fell to roughly £70/month – now covering all home heating, hot water, electrical appliances, and EV driving.
2. EPC Enhancement (D to A):
   • Initial move-in: D
   • After Solar & Battery: B
   • Final post-heat pump assessment: A
3. Resilience & Market Value: Achieving an EPC A rating equips the property for preferential Green Mortgage rates. Decarbonising your home and car also hedges against future fossil fuel price spikes.

What’s next?

Is a Heat Pump Right for You and Your Home? Independent Advice from Loco Home’s Founder

Lessons Learned & Key Takeaways

1. Prioritise Design: A comprehensive heat loss calculation is crucial. Oversized heat pumps installed without accurate room-by-room designs run inefficiently and fail to heat spaces evenly. Learn more how Loco Home can help with our Heat Pump Plan.
2. Ensure Accurate EPC Assessments: EPC assessors require exact technical inputs. Default assumptions can downgrade the rating you’ve been working hard to achieve. As part of our service, we can help and provide guidance so you’re not in the dark with EPCs.
3. Demystify the Technology: Heat pumps achieve efficiencies well above 300%. From watching Heat Geek on Youtube to meeting happy heat pump owners (we can help with that!) familiarise yourself with the basics so you can feel confident in your next steps.

https://www.rettie.co.uk/property-sale/gwe260422