Development plan in NRW - is a attic possible?

Hello everyone,

I have a question regarding our development plan in NRW.

A 1- or 1.5-story construction with an eaves height of 4.50 m and a maximum building height of 9.50 m is specified.
As far as I have researched so far, this means that in the upper floor we are allowed a maximum of 2/3 of the area of the ground floor.

My question now is how this applies to a desired attic? Is a house allowed to have a ground floor plus an attic under this development plan at all?

I would interpret the law so that the area of the attic + the area of the upper floor may not exceed 2/3 of the area of the ground floor, right?
Can someone confirm this?

If this is the case, is there anything against building a balcony or a roof terrace on a bay window in the upper floor that can be accessed from the attic?

I hope the question is not too specific…

Thank you in advance.

Regards
Matze

I understand a 1-story building as a ground floor and an attic. In my opinion, there can be no upper floor [OG] in between.

Both are incorrect or expressed unclearly. Sorry.

A single-story construction means the full floor. As long as the basement is not built as a full floor, it is allowed. As long as the other floors above the ground floor are not full floors, they are allowed. There are no half floors.

As far as I have researched so far, this means that we may have a maximum of 2/3 of the area of the ground floor on the upper floor.

You are allowed to build over the entire area. The 2/3 (if they are correct, which you researched for NW) refers to the living height of 2.30 (or 2.20... depending on the federal state). This results from the knee wall and roof pitch. The attic floor in a single-family house with a ridge height of 9.50 and a knee wall of 1.50 will no longer gain any significant livable height.

Is a house allowed to have an upper floor plus an attic floor according to this development plan?

Yes... If you don't have an architect yet, you should read up on the basics ... just as a tip. Could it be that you are not the only one building there? I read these values independently here already 2? times recently. ?

If that is the case, is there anything against building a balcony or a roof terrace on a bay window on the upper floor that can be accessed from the attic?

Bay windows are fancy features that become even more expensive with roof terraces. In my opinion, balconies are primarily something for apartments, and if you have garden access, you "need" them less. Also, a roof terrace "creates" additional living space, and you have to be able to get there - usually through a roof extension of more than 2.30 m in height...

I read those values here recently, maybe twice independently. ?

That doesn't ring a bell with me. The values aren't really that extraordinary.

Hello everyone,

first of all, thank you for the answers. Let's leave the roof terrace aside for now. I am mainly interested in the question of whether a developed attic is allowed if it offers living space.

As long as the additional floors above the ground floor are not full floors, they are permitted.
There are no half floors.

From this I understand that a developed attic is definitely permissible in the case of single-story construction, right?

I would see it like this now, that the living space of the attic as well as the top floor must not be larger than two thirds of the living space of the ground floor, right?

Regards

Matze

From this, I understand that a converted attic is indeed permissible in single-story construction, right?

Yes, as long as all floors above the ground floor have pitched roofs and are not higher than 2.30m over more than 75% of their floor area.

I would now assume that only the living area of the attic as well as the upper floor must not be larger than two-thirds of the living area of the ground floor, right?

Where did you get the two-thirds from? It’s about 3/4 of the respective floor area of the floor.

This is also a single-story house in NRW.
Of course, the zoning plan may include many other provisions that do not allow this, e.g. eaves and ridge height, plot ratio, roof pitch.