Renovation costs

But what I actually hoped for with this thread: Imagine you were renovating a house. You have free choice of money, location, and technology. What energy-saving measures would you take now and why? And which heating technology?

Overall, I find your plan very good.

But I would plan bottom-up: Clarify with experts what can be done for around 150,000. Then determine: Is that enough or not? Or, what do you leave out to stick to the budget.

If I were in the quoted, fictional situation:
- Produce insulation / floor construction / windows / exterior doors so that at least Energy Saving Ordinance 100 is achieved. Inquire about subsidies for modernization at KFW! This modernization is certainly eligible for funding based on the criteria.

- Install underfloor heating where appropriate (modern heating systems can run both an underfloor heating circuit and a circuit for radiators in parallel). Of course, with checking by heat load calculation after the final insulation values are known.

- Use a heat pump. Preferably a groundwater or brine heat pump here. They have significantly higher COP (annual performance factors) than an air-water heat pump.

- Consider whether a controlled residential ventilation system with heat recovery makes sense (--> energy consultant). If you're already "opening up" everything, you could install a controlled residential ventilation system. Costs about 10,000 euros though.

- Should it turn out that insulation to achieve Energy Saving Ordinance 100 values becomes too expensive or complicated, relax this a bit, possibly keep the heating concept with gas condensing boiler / oil condensing boiler and radiators (again after heat load calculation). However, in this case, a thermal solar system (at least for domestic hot water) might be necessary; this also costs 4,000+ euros. Consider whether instead of a controlled ventilation system with heat recovery, a passive ventilation (windows) can be installed.

- Save: For now, leave the concreted area in the garden as it is. Removing 300 sqm of asphalt/concrete is expensive. The outdoor facilities already exist; you can approach them little by little and successively.

Overall, I *suspect* (without being able to see into the future) that you can accomplish quite a bit with the mentioned 150,000 euros. Although I believe your cost estimates for heating and insulation are set too low. But the appraiser / energy consultant will determine this; as said, since there are several alternatives, you will be able to choose your path.

- Use a water storage tank in sufficient and appropriate size, 300 liters is not bad.

- Make compromises to possibly save money on room redesign / floor plan changes.

- Bathrooms can be extremely expensive, but you can also build something serviceable for much less money.

Best regards Thorsten

That all sounds good. I’ll have to google all the abbreviations later, but for now I agree with the other statements. We have a good structural engineer on hand (who also took care of all my siblings), who already said that the energy-related stuff (actually almost everything that can be declared as such) can be subsidized up to 100k with 15% – as long as it is supervised and approved by a KfW consultant or similar.

As I said: we’ll also look at this with experts the day after tomorrow, and then quite a bit will develop.

I’ll definitely comment again about the abbreviations later... ;-)

So, almost all abbreviations understood... ;-)

Actually, everyone we know has advised against underfloor heating, as well as wall heating (WH?). Too sluggish, too much fuss. Does a mix of underfloor heating/WH and conventional radiators make sense?

In the basement of the house there is a gas boiler (Vitogas 200), I assume it is included in the purchase price and could be used. Is something like that worthwhile? Or sell it and invest in a future-proof system?

I have also heard a lot of negative things from conventionalists about controlled residential ventilation - "Then you can’t open the window in winter anymore" - "not good because it’s prone to malfunctions" - etc. Surely someone here has a different attitude about this, right?

I’m taking the other stories as input for now and will bring them into the conversation the day after tomorrow. My main concern would be to get a lot of light into the house. Old building, small windows (except for one 3.50 x 1.50 window...), little light. I would like to install large skylights or create space and light sensibly with dormers. Of course, in the end it's a question of cost again...

As I said, I’m not very demanding about the bathroom. I really like shower niches with proper tiling, which would be two small drywall walls. Simple bathtub and a simple toilet, done. I hope we can manage with little money... Let’s see what the lady of the potentially future house says about that... ;-)

Almost everyone we know has actually advised us against underfloor heating, as well as wall heating (WH?). Too sluggish, too whiny. Does a mix of underfloor heating/WH and conventional radiators make sense?

No, it makes sense to switch completely to underfloor heating. That is standard nowadays. Why are your acquaintances advising you against it?

I have also heard a lot of negative things about controlled residential ventilation from conventionalists – "Then you can’t open windows in winter anymore" – "not good because prone to faults" – etc. Surely someone here has a different attitude, right?

You can only not open the windows if you unscrew the handles ;). Those tips probably come from people who do not have controlled residential ventilation. The fact is, you don’t have to open a window anymore to ventilate (applies also to the bathroom, and has worked well even when cooking/Raclette etc.). Regardless of the season, the air inside the house is always fresh. It is not more or less prone to faults than any other technical device, maintenance is usually minimal (with many models you can “make” your own filters and replace them regularly). I would always install it again – we have been using it for two years now and are thrilled. The only downside might be that personally you find the air a bit too dry in winter. But there are also devices with humidity recovery. The mood here on the forum is pro controlled residential ventilation.

Nope, it makes sense to switch completely to underfloor heating. That is standard nowadays. Why do your acquaintances advise you against it?

As I said – many half-baked stories. Especially because it is apparently too slow with children. If they are too cold, then they simply don’t feel like waiting a day until all the walls and floors have warmed up. But none of them have had underfloor heating so far. Ultimately, the question is certainly also whether it is that easy to retrofit underfloor heating into the existing floor.

Here in the forum the mood is in favor of controlled residential ventilation.

I thought so. ;-) That will definitely also be a matter for consultation, let’s see what can be done within the budget.

Actually, everyone we know advised us against underfloor heating, as well as against wall heating (WH?). Too sluggish, too much whining.

As I said – lots of half-baked stories. Especially because with children it’s apparently too sluggish. If they’re too cold, then they just don’t feel like waiting a day until all the walls and floors have warmed up. But none of them have had underfloor heating so far. Ultimately, the question is certainly also whether it’s that easy to retrofit underfloor heating into an existing floor.

Prejudices that date back to the last century (also regarding controlled residential ventilation, as those comments probably come from clueless doubters ;)) You want to do a complete renovation of an old house and bring it up to the latest energy standard: underfloor heating is now standard (as already mentioned above), and if your house’s insulation corresponds to today’s standards, the underfloor heating will be there to maintain a comfortable temperature – there’s none of that every-6-hours-turning-it-on-and-off nonsense anymore. Nothing will and should cool down.

There are many threads here in the forum about controlled residential ventilation – just browse and read.

You simply have to disconnect from the stories related to houses from 15 years ago and older. House construction today works a bit differently than for older generations.