Houses needing refurbishment.
100-150 square metres.
Refurbishment is a great opportunity to replace the old gas boiler with an electric alternative. Houses with gardens have the great advantage of outside space, where heat pumps and external units can be installed. Heat pumps should therefore be the default option, but because of costs and redundancies, smaller homes may not always be the best cases for heat pumps. You will find other options here.
Another aspect to consider is the extent of the refurbishment: a well-thought refurbishment project will, in fact, strike a balance between investment in heating systems and in upgrading the building to get the best return (lower bills and less carbon footprint) with the minimum effort.
Depending on the condition of the heating system and your budget, you have the following options:
Heat pumps are ideal for medium-sized properties and especially in the case of extensive refurbishment, Heat pumps work in properties with a reasonable level of insulation (not high). Therefore, the older the house, the more investment is required to bring them to the right level. On average, they will require more investment than other heat engines, but the opportunity of a refurbishment usually makes them worthwhile.
Approximate costs: £8,000 -10,000, including units, cylinder and installation and government incentives (currently £5000)
Option 2 is ideal for lighter refurbishments. If the heating system is in good condition and you may keep the radiators, a combination of a heat battery and a smart hot water cylinder can prove very effective,
You must check your incoming electricity fuse, as you will likely need at least 100 amps.
Approximate costs: £8,500
For very light refurbishments of well-insulated buildings, Infrared heating combined with a smart immersion tank bring the advantage of not tasking too much the electric fuse.
If installing infrared heating panels, the cost will probably be comparable to a heat pump.
If installing infrared thin film, the cost will be higher (hence only valid for very light refurbishments).
Approximate cost: £7-8,000 for infrared panels
£16-19,000 with plastered-in thin film infrared
What else can you do?
The power required to heat the house ultimately depends on how well-insulated the building is and how efficient the heating system. It makes sense to address the building fabric and the heat engine simultaneously: improving the fabric reduces energy requirements, and the cheapest energy is the one you don’t use.
A pragmatic fabric-first approach suggests investing in insulation and draught-proofing in areas that make the most difference. The strategy will vary especially based on the age of the building. Pre-1930s buildings have no cavity walls and need to be handled more carefully. Fitting or increasing loft and ground floor insulation and draught-proofing or replacing doors and windows usually are the best investments.