ᐅ Heat Pump Retrofit for a 30-Year-Old Multi-Family Residential Building?

I own a house with four rental apartments, each approximately 75 sqm (800 sq ft). The building was constructed in 1994, and each apartment has its own gas boiler. Earlier this year, the first boiler broke down, and I had to quickly install a new one to ensure the tenant still had hot water. The cost was €5,800. It’s expected that the other three boilers will eventually fail as well. However, it doesn’t make sense to replace them again with gas boilers.

A friend suggested installing a heat pump and adding blown-in insulation to the exterior walls. This could be done without disturbing the tenants. The roof is also well suited for photovoltaic panels, as it is free of shading on the east and west sides.

How would the billing work if the heat pump is partially powered by the photovoltaic system? I want my investment to benefit the tenants not only financially. Are there any subsidies or grants available for rental properties?

Heat pumps could replace individual gas heaters or be installed as a central system. However, for billing and operation purposes, individual units are usually better. There are compact, slim devices suitable for replacing individual heating units. Unfortunately, installers often charge unreasonable prices for these.

A house built in 1994 typically has a decent exterior wall. If there is a ventilated cavity behind a brick facade, it should be evaluated on a case-by-case basis whether adding internal insulation makes sense. As a general rule, this is usually recommended only for older buildings constructed before 1978.