Start of construction & completion notification for outdoor sauna in Hessen

Hello,

we needed a building permit for the outdoor sauna. Now it is finally finished and was professionally installed by the sauna builder within 3 days. With the building permit, we have various documents such as the construction start & completion notification. Do I have to contact the planning office for this, or can I fill it out myself? Can I submit both at the same time since it only takes 3 days?

What happens if I don't submit it? Is it then formally an "illegal construction"?

Thank you very much

Well, construction may only begin 14 days after the submission of the construction start notice. So it's basically already an illegal building. But you can fill out and submit both yourself, that is also your duty as the builder.

Well, construction may only begin 14 days after the building start notification has been submitted. So it's basically already an illegal construction. But you can fill out and submit both yourself, that is also your duty as the builder.

No, I'm still within the 14-day period... Then I'll fill it out and submit it.