I have a house from 1978 and I'm wondering whether I should replace the old oil heating with a heat pump. Heating costs have just shot up like crazy, but I've heard that heat pumps don't work as efficiently in older houses. Has anyone done something like this already and can tell me roughly what it costs?
First things first: With a house from 1978, you need proper insulation beforehand, otherwise you're just throwing money away - heat pumps love well-insulated homes. If your exterior walls and roof are still in their original condition, you should renovate those first before you invest in a heat pump, otherwise it'll be running at full capacity constantly and your electricity consumption will be horrendous. The heat pump itself usually costs between 15,000 and 25,000 euros plus installation, but without prior renovation you won't save anything in the long run - quite the opposite actually.
Before you ditch the oil heating, get a proper energy consultant to come to your house - not just the tradespeople who want to sell you a heat pump. That's the crucial point a lot of people miss. A house from '78 can actually work with a heat pump, but the efficiency really depends on how your heating surfaces are sized. If you still have old radiators that are designed for 70 - 80°C, you'll either need a very large heat pump (expensive, bad for electricity consumption) or you'll have to switch to underfloor heating. An energy consultant will look at it properly and tell you whether renovation makes sense first.
On the costs: A heat pump alone runs between 15,000 and 30,000 euros net depending on the type (air, ground source), then you've got disposal of the oil heating, possibly a new buffer tank, electrical upgrades on top of that. If you insulate first - roof, top floor ceiling, maybe basement walls - you'll cut your electricity consumption dramatically later. That pays off in the long run. Here's the thing though: A lot of people put in the heat pump and save less than they hoped for because the building envelope is just too poor.
There are subsidy programs from the government, but the conditions are very specific - the energy consultant should look into that too before you sign anything.
I wouldn't be so pessimistic about it - older houses can handle it too if the heating surfaces are large enough (underfloor heating or chunky radiators). What really matters is less the insulation than the flow temperature your heat pump needs. Get an independent energy consultant to come by who also looks at alternatives - some older buildings make more financial sense with a modern gas condensing boiler plus solar thermal heating than with a complete switch over.
With a heat pump in an old building, you actually do save money, but the whole story is a bit more complicated than "insulation first, then heat pump." Heating costs have gone up, yeah, but whether a heat pump pays for itself really depends on your specific situation - and to be honest: a lot of the optimistic claims ignore the fact that old houses actually work differently than new builds.
The problem is less about efficiency itself than about reality. A heat pump runs better with low flow temperatures (around 35-45 degrees), but with older houses you often need 55-60 degrees because the big old radiators just demand it. That does make the heat pump less efficient, true. But: even with this "penalty," you'll do better economically as energy prices keep climbing than if you just keep going like you are now. The investment is steep - I'd estimate 15,000 to 25,000 euros, depending on the work involved and whether you need boreholes for ground source probes or just use air heat. There's state funding available, but it's gotten tricky lately, so get some proper advice on that.
A real energy audit (independent, not from a contractor who's trying to sell you something) is absolutely worth it - that's money well spent. They can tell you whether your house should be insulated first or whether a heat pump actually makes sense despite the old building handicap. Sometimes a hybrid solution works better: heat pump plus your old oil heating as backup for extremely cold days. That's possible too, but it's a different calculation again.
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