ᐅ Energy-efficient renovation does not pay off! What can be done?

Hi friends. We are considering buying my in-laws’ timber frame house. The house was built in 1979 and, apart from the roof (14cm (5.5 inches) above-rafter insulation), it is not insulated. The wooden windows are also from 1979. Of course, the windows are old, but overall everything is still in very good condition. The energy costs (electricity + gas) for the 130 m2 (1,400 sq ft) house are 2,600 euros. Compared to insulated houses, this is quite high. Therefore, we have been thinking about an energy retrofit. However, the quote for new windows alone is 60,000 euros. In addition, there would be basement insulation and possibly interior insulation for the roof. We have ruled out exterior wall insulation. Altogether, this would probably total around 80,000 euros (including own labor).

These renovations would certainly reduce the energy costs. But even if I save half of the costs going forward (which is probably optimistic), over 40 years (I will be 85 years old then, I don’t expect to live longer), that amounts to 52,000 euros. So it is far from a cost-effective renovation... and theoretically I would need to replace the windows again after 40 years.

Honestly, I am thinking it might be better to do nothing (apart from aesthetic renovations) and live for the next years in a renovated house (but with a lower purchase price, about 280,000 euros) and bear the “higher” energy costs — especially considering rising CO2 costs, etc. Even if I assume the gas price doubles and receive a subsidy for one of the above renovations, it still wouldn’t be worthwhile. The resale value is also not decisive because the house is in a rural area — so rather a lower-demand location.

What do you think? Am I missing something? Is anyone else in this situation? What would you do?

PATPATPAT schrieb:

However, the quote for new windows alone is already 60,000 Euro.

THE quote or multiple quotes? What special requirements do you have? For such a small place, that quote is at least twice as expensive as it should be.
What about the front door?

PATPATPAT schrieb:

Then there’s the basement insulation.

From the outside, or do you mean the basement ceiling? Is the basement living space or just storage? Is it open above or does it have a door and stairwell?

PATPATPAT schrieb:

Possibly interior insulation for the roof.

Is the attic used as living space or not? Interior insulation for the floor or between the rafters?

How old is the gas heating system? What is the flow temperature? Are you considering replacing the heat generator (heat pump)? What types of radiators are installed—have you thought about using 33 mm (1.3 inch) radiators at the largest size possible?

Why so many questions? Because there is very little information from you in your thread—mostly just complaints about the costs.
I can tell you that, for example, with new windows, new radiators, roof insulation plus basement ceiling insulation, and a heat pump, the heating costs would very likely drop to under 1,000 Euro, including hot water.

What you’re forgetting is that energy costs will increase in the future, simply due to normal inflation. In 20 years, €2600 will already be about €4000 per month with a 2% inflation rate. If you also factor in price increases for gas and CO2 emissions, I would expect at least €5000 in 20 years. Probably even more, especially if gas heating systems are still a thing by then.

In contrast, electricity combined with a heat pump will likely remain very affordable, as we continue to expand renewable energy sources, which are the cheapest form of energy. That makes sense, and hopefully, this whole debate will be over in 20 years with proper implementation. You will need to buy a new heating system within the next 20 years anyway, and a heat pump is not very efficient in a completely uninsulated house.

A loan of €80,000, on the other hand, if arranged under good conditions and stretched over a long period, will effectively become cheaper due to inflation. This is essentially the reverse of the principle mentioned above.

Your calculation makes sense if everything stays exactly as it is. But that is very unlikely, as natural development and climate change will force progress. Betting on 16 years of inactivity under the CDU would be too risky for me. In that case, I would all the more take out a loan, so you can directly plan for a pool and air conditioning as well.

P.S. Please don’t calculate everything in euros alone. There is also quality of life to consider. When I’m sitting on the sofa in winter and feel the cold coming from the adjacent window, whose glass still has a U-value of 3, I would certainly appreciate modern glass with a U-value of 0.6.
That also benefits children playing on the floor in front of the patio door.
Just an example and a thought to keep in mind that not everything can be measured in money.

P.S. 2:

PATPATPAT schrieb:

but lower purchase price approx.: 280,000 euros

Without energy-efficient renovation in the next 10–20 years, the value will tend to drop to the land value. You will have invested a lot into financing (or lost equity) and end up with nothing. It might be better to stay in a modern rental property.

Why would you renovate everything without any subsidies? Especially for projects like these, subsidies are fantastic—you can easily get up to 40% of the costs covered and benefit from relatively favorable loan conditions on top of that.

This makes any discussion about financial viability unnecessary (although the other arguments are also completely valid).

Hi nordanney.

This is a house with an exposed roof structure (5m height (16 feet)) and on the narrow side there is a full window wall with fixed triangular windows and a huge sliding door. Despite choosing (more affordable) plastic windows, replacing them seems to be difficult and therefore costly. Additionally, there is the shading for this window wall and 6 more standard double windows, some with roller shutters.

By basement insulation, I mean ceiling insulation of the basement. The basement is not used as living space. The staircase is open (but there is consideration to separate the basement with a drywall partition and door).

Of course, we have thought about the complete package: new windows, new radiators, additional roof insulation + basement ceiling insulation, heat pump, and solar panels — but in that case, I’m definitely looking at over 100,000 Euro, more likely around 130,000 Euro, and even if I were to reduce my current costs from 2600 Euro to 600 Euro (which is probably wishful thinking) — the investment would still only pay off in at least 50 to 60 years…

The gas heating system is about 25 years old… I can’t say the flow temperature…