Hello,
I have read so much and am completely confused. And I am not alone, because with many topics you get the impression that the thread creator would prefer to read the concrete answer to his problem as the first post and then stick to it without further thinking.
This is generally rooted in human nature. For example, if he wants to buy a refrigerator, he goes on the internet and suddenly has comparable information available. Then he only has to look at his account and can order; of course again preferably on the internet; at this point, he does not think about possibly necessary maintenance/repairs, nor about the - very likely - more competent local retailer around the corner. Why should it concern him now that in the future there will only be box stackers without professional competence, if his example (and unfortunately that is increasingly the case) becomes the norm?
Similarly, he approaches the topic of house construction; he has once used a hammer, even covered the walls with a coating; maybe he also knows how to build a drywall. Why shouldn't he be able to manage house construction "in a snap" with his already acquired "knowledge" - spiced up by forums like this? The bad thing is: although there are standards for everything in Germany, unfortunately there is
no mandatory training for salespeople and not infrequently there is a rude awakening in the end when the tips given by others, presumably experienced users (who of course have also already tried handling hammer and chisel) and/or salespeople support the already existing "knowledge".
So if I ask a few questions now, I do not expect universally valid answers. (I can already imagine €uro replying that this simply needs to be calculated).
€uro is right about that too. He and I answer knowing that only a vanishingly small portion of users (for the aforementioned reasons) will take to heart his quite well-founded answers, because his answers cost money in practice; money which is usually rather invested in an "extra" than in the security of the materials used in house construction.
Does a house offered according to the Energy Saving Ordinance (i.e., a house that meets the minimum requirements) also offer a reasonable basis? I have read so much about KfW 70 that you get the impression that anyone who does not reach this standard is doing something wrong. (I can already see all my future neighbors turning up their noses)
Firstly, you are not building your house for the neighbors - or do you also carry that label on your suit sleeve? Secondly - yes, if you can/want to afford it, you should build a KfW 70 efficient house; at least align the masonry/basic technology (underfloor heating) with this goal. With the latter variant, you always have the option later to retrofit to KfW 70 or lower, since it is always technology.
If affordable, then KfW 70? KfW 70 is not always economical? If you set KfW 70 as a goal, then always a cost/benefit calculation with real values? (I have often read DIN here via €uro)
Sure - how else? My field is solid construction, so I take an example from this area. A classic, detached single-family house of 120 sqm living space (see attachment), monolithically on slab, costs - according to the current Energy Saving Ordinance - about EUR 180,000; the shell and installed basic technology are already aligned to KfW 70, in case the customer wants to upgrade to the efficiency status at a later time. The step to KfW 70 costs about EUR 10-12,000; it can only be exactly specified after the structural engineer/technical planner has calculated. According to feedback from our customers, a KfW 70 efficient house results in about €600-800/month cost for heating and hot water for the builder; depending on showering habits.
Basis for the question is an offer for a house. (Bungalow, 104m², solid construction) It includes a condensing boiler and solar for hot water preparation. For KfW 70 more insulation and a residential ventilation system with heat recovery would be added. The extra cost would also be affordable.
From my experience, I doubt that these measures alone will be sufficient. It also depends on the location of the plot relative to the sun, what U-value (window and frame) of the windows is planned etc.
That also seems to be the standard program. Condensing boiler and solar are always included initially. The rest to KfW 70 then the easiest way. But maybe not the best and most economical.
That means initially a house offered according to the valid Energy Saving Ordinance. The question of whether the Energy Saving Ordinance or also KfW 70 is economical cannot be answered only by the costs of additional technology/ subsidies. It also depends on what your purpose with this house is: do you want to live in it, maybe rent it out later, sell, or inherit?
At the moment I rather favor not KfW 70, but leaving out solar and instead insulating 15% better. (15% rule, right?). A worthwhile alternative?
There is no right or wrong! Whether with the above or this variant, costs will always arise for you. Only you can decide for which implementation you want to spend the necessary money. However, I strongly advise you not to forgo controlled residential ventilation with increased insulation; the house will become simply too tight in this approach, so that you should not afford the luxury of dispensing with it!
At least I would like an outlook on how I can make the best of the situation. Which route should I take for planning? Will the building company calculate such things reasonably or better have it calculated externally right away?
As you can easily see from my answers here, I am not a fan of "all-rounders," especially not those active nationwide. €uro can sing a song about calculations of the necessary technology, I another about handling with building companies/builders.
So that there is no misunderstanding: the vast majority of providers build decent houses, deliver a good service - even if the HBF gives a different impression (satisfied builders rarely if ever go to forums). But they cannot provide the support/customer contact as smaller to medium local building companies usually do. In addition, these building companies do not have to finance a comparable bureaucracy as larger providers do; nor can their salespeople afford to discredit their employer. I always jokingly call it: "our customers know where my car lives."
I always recommend cooperating with a local architect and a local builder; the architect knows his "people" and will not give his clients poor advice. Even if it is often said the architect cannot maintain the estimated price, this is precisely not true when the builder recommended by the architect calculates the new construction based on the specifications before signing the contract; we work btw. exactly this way. Another advantage of this approach: the offer from the builder then really includes all costs - also e.g., painting and flooring work, the access way or the creation of the terrace. What remains then are the pure land costs such as land transfer tax, house connections, and notary/court costs. Equipped with this plus some euros for extras (e.g., a new kitchen), no financing can fail because additional funding is required. Many salespeople find it very difficult to name the typical incidental construction costs - after all EUR 35-40,000 without foundation extra costs, without painting/flooring and without outdoor facilities including garage - because first and foremost it is about getting the contract signed.
Another advantage: once cooperation with an architect is decided, he also creates the working plans for the builder. I have often experienced that large, especially nationwide providers, do not create exact working plans. If something goes wrong during the actual construction, the blame is quickly shifted to the builder. However, this blame is often incorrect since the builder only carries out what the provider has given him in terms of working plans.
Among other things, poor working plans are a logical consequence of the "stingy is cool" attitude of the vast majority of builders. Everything must be cheap, after all, the "knowledgeable" builder knows how to handle hammer and chisel and of course everything in the hardware store is so much cheaper. If the project has failed with this "help" of the builder, you will find ample reports in the forums; also in the HBF.
I cannot count anymore how often I have written that a piece of house - with comparable providers - always has to show the same price bottom right
must; +/- EUR 6-8,000. Unfortunately, it rarely falls on fertile ground - similar to €uro’s answers here, and so the circle closes again.
For you, this means that you must first clarify with your wife/family which route you want to take: large provider or regionally active builder. Only
after that should - based on the floor plans developed together with the architect - the question of Energy Saving Ordinance or KfW 70 be clarified on the basis of conclusive documents; this procedure applies both to the large provider and in any case to the local builder.
Kind regards
