What to replace an oil heater from 1989 with in an old witch's house?

Hello dear forum,

we have an old witch’s house in the Alpine foothills. Built around 1910 with an extension from the 60s, the old building has a basement, the new building does not. The insulation is rather poor, the windows are either double-glazed or old. A hailstorm destroyed our entire roof, so now a new roof with good insulation has been installed.

Currently we have a Viessmann oil heating system from 1989 with a 2000l oil tank in the basement, which has not caused any major problems so far. The hot water is also centrally prepared by this system. With the old roof, we needed about 1900-2500l depending on the winter, with the new one there are no experience values yet, I suspect a slight improvement. The house has about 115m2 living space, which is heated via radiators.

Since the heating system is getting old and there are currently larger funding programs, we are considering a modernization. From my research so far, a heat pump unfortunately is not an option because we would need a better-insulated house as well as underfloor heating? Other types of electric heating seem even less economical?

The least invasive option would probably be a new oil heating system with condensing technology, but these are not subsidized, so I can also wait until the old one breaks down?

A pellet heating system seems too complicated to operate? My mother will soon be 70 and often lives alone in the house. I do not want to impose major burdens on her as she gets older. We regularly visit with our child for several days, but mainly in the summer. Also, the long transition period during which the heating runs only at low load seems to speak against a pellet system.

With gas I can’t quite estimate the costs. A gas connection would probably be possible for the local supplier if the neighbors participate. We would then need about 60-70m of gas line on our own land. What kind of costs should I roughly expect? Alternatively, one could bury a tank in the garden, but we are not enthusiastic about that idea. We are somewhat confused by the current politics, on the one hand it is said that fossil fuels should be massively more expensive to promote renewable energies, on the other hand gas condensing units are massively subsidized?

For romantic reasons, we could imagine installing a water-bearing stove in the living room. Currently we already have a wood stove in the kitchen on which we occasionally cook, which also provides some heating in winter.

However, it would have to use the same chimney, where currently the oil heating or the future gas heating is connected, and as far as I understand, that is not allowed, so I have to give up that dream, right?

On the roof, we are thinking about a photovoltaic system, but we are considering removing the attic and renovating the top floor in about 5-10 years so that it has higher ceilings. In the course of this, a few skylights would be added. I should probably wait for these renovation measures first.

What would you recommend? How should the new heating system be sized – that should be quite well calculated from the previous consumption values, right?

Thank you very much for your time and help!

Another energy renovation is neither planned nor desired? Are the oil tanks still in good condition? I would stick with the old one and optimize it a bit. There are good results on Google for that. 60m of gas pipe will be very expensive, I estimate. The supplier has cost breakdowns. Flat rate up to x meters and then y euros per meter. I am not a fan of oil and it is not foreseeable what future governments will do, but here I see oil as an economic option. Pellets no, but wood gasifier? Makes little sense because it requires much more work.

Are the oil tanks still in good condition? How can I find out? They were renovated about 10 years ago, at least no oil is leaking or anything like that. Hmm, we already had an energy consultant here and further energy renovations unfortunately didn’t seem particularly useful. Gradually, we will probably replace the windows if it becomes necessary. Insulation measures seemed to pay off over a period of 25-30 years (without interest), after which period you can probably install new insulation again. We just have smaller amounts of our own wood that we like to burn from time to time. However, you can’t build a heating concept on that, especially if it has to be operated by a person over 70 years old.

I would do what seems sensible to me. First of all, I would exclude the topic of [Förderung]. If I still end up there, okay, but I would not align my measures with a [Förderung]. You all want/can't complete all the planned measures right now, so I would not replace a functioning heating system. Once the topic of [Photovoltaik] is clarified and can be implemented, infrared heating supported by wood or similar could also be an option. Take a look across the border to Austria; they are quite innovative in this regard. Ultimately, as always, it depends on the individual needs/benefits; in general, I could also well imagine liquid gas. Especially the older person probably likes it simple and functional.

Interesting topic, I'll join in reading.

We also planned to install a new heating system in Grandma's house because she heats with night storage heaters, but it is very expensive.

On the other hand, if you offset the costs for a new heating system of any kind, you might as well forget it. It won’t "pay off" in 30 years, just as you wrote.

Long ago, heating was done with oil individual stoves in every room, using oil cans.
That’s why there are still two chimneys in the house. We also considered installing a wood stove in the kitchen and a wood-burning stove in the living room and investing in new stainless steel flues for the chimneys.

Regarding carrying wood: I wonder how the old farmers survived.
It is laborious, but exercise is good if you want it. And if you bring in each piece of wood once a day. They only wanted to store the wood outside because of the crawling critters. (It’s bad enough if the cat brings half-alive "gifts" like mice). She would have liked to have stoves.

Our idea was to install a photovoltaic system on the roof with a battery in the basement and use it to operate new infrared heaters and the water boiler.

But we haven’t finished calculating it yet, it’s unrefined and we don’t know if there’s any subsidy if you don’t insulate otherwise.

Do you need permission for a loft conversion?

Do you need a permit for an attic conversion? It totally depends on the conversion and the local conditions, for example, whether you plan dormers, etc. "Especially the older person surely prefers it simple and functional." My mother still enjoys working with wood. So not just heating but also chainsaw + chopping, and we already have a wood stove in the kitchen, but you just cannot rely on it staying that way.