Payment terms for prefab house

I would like to see that sometime, the current scope of work description from April 2017 does not include any material thicknesses or any details about installed materials. I have it right here in front of me.

Here are a few quotes from the construction performance description that the building expert also criticized and wanted clarification on, which Okal Haus was by the way not willing to provide:

"high-quality fiber cement material as plaster carrier" - what material is that? Which manufacturer? Basically, Okal Haus can plaster anything on your wall with that

"quality-tested gypsum fiberboard" - no indication of material thickness

"the spaces in between are filled with precisely fitted mineral insulation" - no indication of the material and/or manufacturer, here too Okal Haus can install anything without your consent

Here is another serious issue that, according to the expert, is outrageous nowadays:

"As an important component in the Okal Haus energy-saving concept, all windows with sashes are equipped with an excellent triple thermal insulation glazing with a Ug value of 0.6 W/(m²·K). The aforementioned specification does not apply to roof windows, fixed windows, or functional glass, such as glazing with increased sound insulation requirements or requirements for fall protection."

This means that all fixed glazing does NOT get triple glazing, which is unacceptable in times of ventilation systems and frequently used fixed glazing...

Only once revised one of the mentioned criticisms. If I were to dismantle everything so far, then I could never build a house or which construction performance description is perfect

The roof windows

Roof windows – if provided for in the contractual floor plan – consist of a thermally optimized hollow chamber profile with a light white plastic surface. The triple-glazed roof windows are also equipped with energy-saving thermal insulation glazing.

I did not speak about roof windows but about fixed glazing.... And except for [Okal Haus], I don't know any construction specification where the materials and material thicknesses are not mentioned... But well, you asked, this is just the opinion of me and an expert... Just talk to [Okal Haus] about it, you will see how they twist themselves.... And you haven't planned a single fixed glazing?

If you do not care about the material your future house is made of, then you can really neglect the [Bauleistungsbeschreibung].

Well. It already states which material is used, e.g. gypsum fiberboard. Manufacturer and type designation are rather rarely found in the construction specification and then often with the addition "or comparable". I also don't know what triple-glazed windows are supposed to have to do with ventilation systems. Sure, Okal House may not offer upper-class standards, but somehow the price has to be determined, and for that, perhaps the cheapest available material is used in a thickness that is just technically sufficient.