Provider, prices, costs, experiences

@ construction expert
As I already said, one can argue well about the different building blocks and discuss it for months. Since the clinker bricks would also cost another good 10,000 euros, we decided on the ETICS. Personally, for example, I don't think much of aerated concrete blocks, at least in the residential area. For garage construction it would be conceivable for me, but not for the house.
Thank you very much for the price information for building materials of a garage!

@ €uro
Sorry in advance if I ask stupid questions, but
- What exactly do you mean by a sales-independent consumption forecast?
- What do you mean by real conditions?

Hello,

....
- What exactly do you mean by a sales-independent consumption forecast?
- What do you mean by real conditions?

Builders are mostly just handed an Energy Saving Ordinance or KfW certificate. The final energy stated there has nothing to do with the consumptions that occur later. The reason for this is that standard values are used there, which have nothing to do with the actual conditions of the construction project. The Energy Saving Ordinance or KfW certificates serve exclusively primary energy comparison purposes (as intended by the legislator) and are neither suitable for heating system dimensioning nor for a reliable prediction of later consumption.
Actual consumptions in completed construction projects are usually significantly higher, especially if the executed technical solution does not correspond to the previous assumptions.
Thus, a KfW EH70 or EH55 that is "nicely calculated" on paper becomes a completely normal Energy Saving Ordinance standard or even worse.

By sales-independent, I mean that this forecast should not come from the seller, or if it does, it should be reviewed by an independent party.

Real parameters are, for example:

- the actual climatic location,
- the actually desired room temperatures,
- the actual hot water demand based on the number of people,
- the actual operating parameters of the heating system, hot water preparation, solar thermal system, and, if applicable, ventilation.

The latter have a significant influence on overall energy efficiency and thus on later consumption costs.
It can happen, for example, that a solar thermal system actually delivers hardly more energy than the control system and solar pump consume in electricity. Or a heat pump achieves a significantly worse annual performance factor than originally assumed due to insufficient planning/dimensioning of the overall system. A controlled residential ventilation/heat recovery does not reach the assumed efficiency of heat recovery. Heat generator and heat distribution do not hydraulically match or are not coordinated with each other. Etc.......
Very often, several of these factors apply at the same time. This results in an accumulation of negative effects, with the outcome that the builder must bear significantly higher consumption costs in the long run, although an EH70 or EH55 was paid for!

Best regards.

Hello,

As I already said, you can argue well about the different building blocks and discuss them for months. Since the clinker would also cost well over 10 thousand euros, we decided on the ETICS. Personally, for example, I have nothing to do with aerated concrete blocks, at least in the living area. For garage construction I could imagine it, but not for the house.

I do not want to argue with you and will not do so; life is too short and the daily struggle for bread too exhausting.

However, I do have something against aerated concrete being spoken of worse than it is by self-proclaimed prophets – and there are plenty of those on the net (you are not meant) – personally, I do not want to live in a "plastic foil," nor have material on the house that I might have to dispose of as hazardous waste in a few years, if in doubt.

A few years ago, when 17.5 cm blocks were still used, the statement – the sound insulation of aerated concrete is insufficient to poor – was completely correct. Today, however, we are talking about 36.5 cm and more – where exactly should there be a problem with sound insulation? Topic interior walls – also such a Jehovah’s Witness topic. On the ground floor, neither KS nor hollow brick is needed, and in the attic, lightweight construction (also gypsum boards) is a very good solution (even if, again, the prophets see it differently); for the very noise-sensitive, KS is recommended – aerated concrete tolerates a material mix better than any other stone.

The most important thing, however, is and remains that you can build monolithically with this stone; comparably, you would spend significantly more money per stone with hollow bricks if you want to do without ETICS. But then there is still the risk of drilling, which admittedly is solvable if a pack of lightning cement is within reach.

So your decision remains yours and I will by no means undermine it. What I would be interested to know is whether you considered a ventilation system in your construction project?

Kind regards

@ €uro
Thank you for the detailed description. Then I will inquire about energy consultants to be able to make such a forecast.

@ Bauexperte

I do not want and will not argue with you, life is too short for that and the daily fight for survival too exhausting

I agree completely

What I would be interested in is whether you have considered a ventilation system in your construction project?

Yes, a ventilation system with heat recovery is planned. Only in this way, according to the sales consultant, can we achieve KfW 55. Why do you ask?

Regards Schuschi

....Only in this way do we reach KfW 55 according to the sales consultant.

You can also reach KfW EH55 without controlled residential ventilation/heat recovery. High efficiency rates of heat recovery are often used to "boost" the primary energy on paper.

Best regards.

Hello,

Yes, a ventilation system with heat recovery is planned. Only in this way, according to the sales advisor, can we achieve KfW 55. Why do you ask?

Nowadays, buildings have to be constructed so "airtight" that even monolithic systems often reach the limits of what is acceptable. With ETICS it is certainly the case that ventilation is mandatory if you want to avoid mold in the long term; whether this must include heat recovery should be calculated by your structural engineer and not your salesperson.

Kind regards