FLATS: 40-90 sqm, not needing refurbishment.
"A boiler needs replacing" was the scenario we originally devised to investigate and solve. Small flats without gardens or terraces and that are not planned to be refurbished are the category that will make or break our transition away from gas. For it to happen, we need cost-effective, simple solutions.
Depending on the condition of the heating system and your budget, you have two options:
Install a heat battery boiler, like the Tepeo ZEB, to supply hot water and heating. You remove the existing boiler and plug in this new one.
40 to 90 square metre flats should be well within the ZEB's energy capacity, but if you think your property has very high needs or you like very long showers, you can look into option 2 below.
Approximate cost: £6000 installed
If you want more peace of mind and the possibility of running hot water from two showers simultaneously, you can combine the heat battery above with a smart immersion tank. The addition of the tank gives you more power output, more flexibility of use and ultimately reduces your bills because you are almost guaranteed to charge only at night.
Approximate cost: £7800 installed
Even without refurbishing, you can always consider minimal improvements to the building. Sealing front doors and leaky windows brings amazing returns in investment and comfort. Replacing or increasing the loft insulation does not require any invasive work. Sometimes, smart robots can also insulate under the ground floorboards through the undercroft.