Hey, great tip. Let's see... - Hmm..., 52 pages, 79 paragraphs OK, full text search for terrace quickly yields a result regarding procedural exemption: Annex to §50, paragraph 1 l) Terrace roofs indoors up to 30 m² floor area, Too bad, OP gave no information about size. Well, 7m wide. Then the roof would have to be more than 4m deep to require approval - unlikely. So we assume it is approval-free. But is it permitted? §5, paragraph 1, sentence 1 Distance areas must lie in front of the outer walls of structural installations and must be kept free from above-ground structural installations. In conjunction with paragraph 2 The distance areas must lie on the property itself. so not permitted. But hold on. Paragraph 1, sentence 2: A distance area is not required in front of outer walls on property boundaries if according to planning law provisions 1. building on the boundary is mandatory ... Too bad, OP gave no statements about planning law. ... unless the existing development requires a distance area, or Too bad, OP did not show a site plan on which the existing development could be seen 2. building on the boundary is allowed and is legally secured that the neighboring property is also built on the boundary. Too bad, OP gave no information about building encumbrances. And now there are another 74 paragraphs. Which are still relevant? And does the neighbor have to agree? Help! Where does it say?
Well, e.g. §5 Building Code of the State of BW: (6) In the measurement of the distance area, the following are disregarded 1. subordinate components such as cornices, roof overhangs, entrance and terrace roofs, if they do not protrude more than 1.5 m beyond the outer wall, 2. projections such as walls, bay windows, balconies, door and window projections, if they are not wider than 5 m, do not protrude more than 1.5 m and remain at least 2 m away from neighbor boundaries. Furthermore, subsequent thermal insulation of an existing building is disregarded if it, including cladding, does not protrude more than 0.30 m beyond the outer wall; if subsequent insulation of the roof leads to a greater wall height, the additionally required distance area is credited accordingly. Maybe that’s enough?