For projects requiring a building permit, a building permit grants you the right to construct a structure, make changes to it, or change its use. It is a declaration by the state that the project does not conflict with public law, which must be reviewed during the building permit process. However, this applies only as of the date of the decision.
Projects Not Subject to Permitting
A project is not subject to a building permit if it is exempt from the permitting process or is exempted from the requirement for a permit. Projects that have minimal relevance under building law are exempt from the permitting process. Projects may be exempt from approval if, in particular, they are not special structures and comply with a qualified zoning plan. However, this depends on the municipality. If the municipality wishes to conduct an approval process, the construction project is not exempt from approval.
If the project is not subject to a building permit, you do not need to apply for one. Such a permit would not be granted to you anyway.
Consequences of Lacking a Required Building Permit
If you construct or alter a structure, or change its use, without the required building permit, the competent local building authority may intervene and take appropriate measures. This may even lead to an order to remove the structure.
