Annual performance factor calculation for funding (parameters and calculation tool)

You can't say it often enough. I recommend commissioning the planning of the underfloor heating based on the room-specific heat load calculation separately and handing it, especially to this heating engineer, ready-made on a plate. It saves discussions and trouble.

I will ask again. So far, they have said that they do it based on the area of the underfloor heating using a program. How much does that cost?

Read , there the underfloor heating was taken out again at the last minute, the software was also available, but everything was estimated. The correction of the planning without estimation was not better.

Costs should be somewhere between a few hundred to 1000€ for a larger house. If your heating engineer were to charge something for their planning, you could offset that. Where to best commission it, I do not have a concrete tip. TGA planners are the right contact if you find one. Otherwise, there are online services that sometimes are also used by heating engineers, but you should have read up on it yourself and know what matters. In the latter case, you can also work well with your heating engineer, give specifications, pay them well for the planning, and keep an eye on them.

You can't say it often enough. I recommend commissioning the planning of the underfloor heating based on the room-specific heat load calculation separately and handing it, especially to this heating engineer, ready on a plate. Saves discussions and trouble.

Who could be commissioned with this and what is needed for a room-specific heat load calculation? At what point in time is this usually done?

Does anyone have experience with heizlastberechnung.net?

Who could be commissioned with this and what is needed for a room-by-room heat load calculation? When is this usually done?

As early as possible. As soon as the floor plan, insulation, and ventilation concept (controlled residential ventilation?) and ideally also the type of floor coverings are known.