Changes after building permit approval

Hello everyone,

we submitted our building application before the turn of the year, which has already been approved. Now there are a few considerations that are on our minds, hence my questions regarding the approved building application.
If we want to move the house on the property so that we can build a double garage instead of a single garage, do we need to submit a completely new building application?
Or is an addendum sufficient? What does it look like if we want to enlarge the house by, for example, 50 cm? Is a completely new building application necessary or is an amendment sufficient?

We only needed one amendment to move our garage.

Expanding a house affects the entire house: the floor area ratio, the volume, different distances to the neighboring property, different house height...
it's worth asking the building authority!

I assume that at least an addendum to the building permit will be necessary, as the planning can change in parts relevant to building and planning law. This can affect setback areas, the floor area ratio, the building envelope (building lines/building boundaries), sometimes the calculation basis for the proof of the number of storeys in buildings on slopes, the statics, etc. In addition, a new site plan must be created. All documents related to the changed planning must be submitted. The preparation of the addendum is usually carried out by the architect. It is best to ask the building authority directly how to proceed. Each caseworker handles this differently.

Ok thanks for the inquiry, how big is the effort to redo all of this? I’m just wondering what the architect can charge for it?!

I hardly believe that can be judged so generally. It probably depends, among other things, on the building authority and certainly also on who wants the changes. So it's best to ask the architect or he/she should contact the building authority and clarify the matters. For us, until now, it was only trivial things like storage areas, playground, parking spaces for bicycles/strollers. Nevertheless, we needed a new site plan and basically a new [BA]. However, the building authority waived our signature, our architect was able to submit it that way.

Ok thanks for the follow-up question, how big is the effort to have all of this revised and redone? I'm just wondering what the architect can charge for that?!

All plans relevant for the building permit - including the preliminary site plan - must be redone. If you are building via a general contractor/general construction manager, they will base it on a fixed price; meaning, you have to ask them. The surveyor you trust will tell you what a new preliminary site plan costs; a freelance architect charges according to the applicable HOAI. A supplementary agreement should be sufficient for the garage, Rheinische Grüße