and isn’t there a land use plan? You can see the preferred building types and plot sizes there,
You mean a development plan – a land use plan is a different planning level.
Also the approximate plot size,
That can mean two things: if the parceling already exists, this information (as well as the price) only helps to sort interests by plot sizes / prices. But I rather assume that they first want to find out which parcel sizes actually fit the interested parties, their building wishes, and budgets.
Also some questions about which architectural style, how many residential units, single-family house or something else.
To me that sounds entirely as if there is just the intent to designate another building area, but no development plan yet. With feedback from the questionnaires, you can for example form development plan sections: a city villa quarter, or even more specifically a Bauhaus-, a country house-, and a Tuscany street. However, I am surprised,
A new development area was only opened 4-5 years ago at the other end of town. Recently the last building plot there was sold.
because in my opinion that is recent enough to derive the appropriate mix for the design of the new building plots – you could see what was in demand there.
Also the whole thing must be signed,
There will be regulations for the form of this interested parties’ involvement – either in their function as a planning law administrative act or as a council resolution. A bit of seriousness has to be included. It does not play a role in a later building application. However, it is advisable to provide truthful information. Is there any instruction on that? – You will receive a PM from me right away; at the top right you see an envelope symbol.