Renovate old building according to KFW standards

Hello everyone,

I am torn back and forth. We bought a house from the 50s and want to have quite a few things done before we move in anyway, like underfloor heating only on the ground floor because the upper floor has wooden beam floors, otherwise we would have liked to do it upstairs as well.

A new heating system, since there is already a gas heating system in place, we will decide on a new gas heating system with solar.

Then we also want to have new windows installed while we are at it, the ones currently installed are still okay visually, but already almost 30 years old and because we would also like to do something energetically, we would also renew the windows. Here again is the issue of whether to choose double or triple glazing, since we would like to take advantage of the funding, we would have to decide on the triple glazing option, but some say again that double glazing is better for old buildings due to the risk of mold.

I keep hearing from many that dealing with the KFW does not necessarily make sense, I have an energy consultant and according to his plan, I would have to do the following:

[Kellerdeckendämmung von unten]
[Fußbodenheizung in allen beheizten Räumen]
[Fenster- und Haustürentausch]
[Dämmung des Dachgeschosses und des Flachdaches]
[Wärmedämmverbundsystem]
[Luft-Wasser-Wärmepumpe (Luft-Wasser-Wärmepumpe)]
[Kontrollierte Wohnraumlüftung mit Wärmerückgewinnung (Kontrollierte-Wohnraumlüftung+Wärmerückgewinnung)]

It’s all nice and good, but of course all that also costs a lot of money and I do ask myself whether it really pays off in the end if we renovate the house according to the KFW standard.

I would just need a few neutral opinions here, thanks in advance.

Peter

Almost two weeks without a response, and your other thread is rather sparsely filled as well. It requires some effort of imagination from the readers to picture your object described only in text. I see a causal connection to the weak response there.

Hello,

I am still bringing up the topic again. Which KfW standard do you want to achieve with these measures? For our house from 1973, we would reach KfW100 already with the following measures (your list, adjusted):

[*] Basement ceiling insulation from below => for us from above for various reasons, which is somewhat worse energetically.
[*] Underfloor heating in all heated rooms => for us only on the ground floor due to height reasons
[*] Window and front door replacement
[*] Insulation of the attic and flat roof
[*] Thermal insulation composite system
[*] Air-to-water heat pump (Air-to-water heat pump) => if we took gas instead, we would reach KfW115.
[*] Controlled residential ventilation with heat recovery (Controlled residential ventilation + heat recovery) => we are considering doing it, but KfW100 can also be achieved without it.
[*] + Photovoltaic system => you don’t have this in your list, but with a heat pump it is in any case, in my opinion, sensible.

I suspect your energy consultant calculated this for a better KfW class. In my assessment, there is a significant increase in funding from KfW individual measures to the KfW efficiency house. The jumps between the efficiency house classes are then not so great.

Regards

Lukas