Katherine’s Smart Switch to a Greener Home

Heating and hot water Internal walls Technology & Renewables Windows and doors

In 2022, Katherine transformed her flat using a handful of retrofit measures. Her sustainable journey resulted in a more comfortable home using an air source heat pump, internal wall insulation, triple-glazing and more.

Summary

Improved temperature comfort throughout the year

Switched to heat pump technology

Reduced heat loss and condensation through triple glazing

Off gas

The Home

House type: 1980s ground floor garden flat
Number of bedrooms: 2
Wall type: Cavity
Location: Long Ashton, Bristol

I am so proud of my new home. It is not only low carbon, but also warm and cosy and my energy bills are very manageable. What I am most proud of though, is that I haven’t bought anything new in terms of its furnishings; buying second hand, further reducing my environmental impact. Yes, it can be a bit disruptive but it was totally worth it. Very much short term pain for huge long term gain!
– Katherine

Overview

After moving to Long Ashton in 2020, Katherine was eager to start her sustainable home journey using retrofit measures and make the switch to green energy. Her ground-floor garden flat had cold spots, a gas boiler and draughty windows and doors. She needed to save energy by improving the thermal efficiency of her property. With a separately occupied flat upstairs, the measures she could take were required to be as non-disruptive and non-invasive to surrounding neighbours as possible.

Background

Katherine’s primary motivation for renovation was in response to the climate emergency. Secondary to that was the reduction in her heating bills, a positive consequence of the works. She wanted to retrofit in the most sustainable way available to her – installing second-hand kitchen units and decorating with thrifted finds.

Katherine had a good idea before starting her retrofit journey about which changes she wanted to make due to her experience working within the sustainable industry. She wanted to add a porch, heat pump and triple-glazing throughout her property. It was just a matter of cost and time for the installations which made her final decision on the measures she took.

Assessment

The first step for Katherine was to assess her home for heat loss. A thermal imaging survey by the CHEESE project showed her where she was losing heat the most. The results found a cold wall on the north-facing side of the building (impacting her office space) and heat loss around the doors and windows. From these results, she was recommended internal wall insulation in the study to maintain a comfortable temperature inside and triple-glazing.

Next, Katherine wanted to know if a heat pump was right for her property. At the Fully Charged show, Katherine saw that the manufacturer Daikin carried heat pumps that were within her budget. From there, she contacted Go Green Solar (who are an installation partner of Daikin, and one of Retrofit West’s Trusted Professionals) to carry out the work. Go Green Solar helped specify which heat pump was best for her ground floor flat – considering the other renovations taking place, like the window replacement, the current heating set up and legislation around heat pumps. Their survey confirmed most of the radiators would need to be replaced to fit the system due to the flow rates.

The heat pump assessment proposed the following work: supply and install a new 6kW Daikin Monoblock Air Source Heat Pump in position at the side of the building. The works also included rearranging some pipework, decommissioning the gas boiler/supply, and installing all the electrical components such as the thermostat. With all factors considered, the total cost for the heat pump supply and installation came to £10950 (incl 0% VAT). However, with Katherine applying for a government Boiler Upgrade Scheme grant, this reduced the price to £5950 (incl 0% VAT). The Boiler Upgrade Scheme now offers £7,500 grants. Check out the UK Boiler Upgrade Scheme to see how much you could save.

Katherine also evaluated the suitability of solar panels for her garden space and electric battery storage but ultimately decided not to go ahead with these measures as the upfront cost of installation outweighed the benefit to her small flat.

The Challenge

Katherine’s journey was set to be straightforward, however the original building company she had contracted to carry out the internal renovations let her down and were unable to start works on schedule. She only had to wait 2 weeks for the newly selected contractors to start works due to other projects. The contractors DPS Construction Wales (now trading as Mint Construction and Maintenance Ltd) who executed the job were very efficient, organised and friendly. It was also clear that they were excited to work on the project due to its sustainable mission which allowed them to showcase their green skills. Katherine was impressed with their work and ability to coordinate with other trades to make sure all her measures worked well together. For example, when it came to the triple glazing, the communications surrounding U-values between the building contractors and window fitters had to be clear to get the outcome Katherine desired.

Go Green Solar was also mindful of noise regulations when it comes to heat pumps close to residential properties. The unit had to be placed 5 metres away from any living space to comply. This was accomplished by placing it along the side alley, adjacent to the neighbour’s bathroom spaces.

The internal wall insulation advised for the cold wall in the office meant that Katherine had a minor loss of floor space. This was ultimately worth it for the temperature comfort provided.

Solutions

Air Source Heat Pump – 2-3 weeks installation time.
Triple glazing throughout the flat
Internal Wall Insulation
Cavity Wall Insulation
Bamboo flooring, chosen for high sequestered carbon value
Porch addition at the front of the house
EV charger installed on drive
Water tank in airing cupboard

Results

After the renovations, Katherine noticed a consistently comfortable temperature in her home. It is always cool in summer, which is particularly important going forward due to increased global warming. The heat pump’s noise levels are not noticeable to Katherine or her neighbours.

Following the installation of all the measures, Katherine conducted a smaller thermal imaging survey herself, using a thermal imaging camera borrowed from a family member, and found that the cold spots previously identified had been sufficiently dealt with. The cold wall in the office now keeps the heat in during winter and stays cooler in the summer. There are still some cold spots surrounding the window frames, but these have been significantly reduced from before.

So, what’s next for Katherine? Katherine is looking forward to increasing the biodiversity in her garden to encourage bees and insects in her local area. She’s chatting with Compass Garden and Landscape Design to create a pollinator-friendly garden with reclaimed/recycled materials, and a cement-free construction with minimal herbicides and pesticides. She may also do some cosmetic renovations on her bathroom now that her flat is thermally efficient.