Garden shed, pergola, swimming pool, greenhouse: what are the rules to follow when installing an annex in your garden? The need to go through a preliminary process depends on the size of the installation. In a protected area, you must always request planning permission from the town hall (prior declaration of works or building permit) The rules are more flexible for temporary annexes, such as garden greenhouses, arbors or even above-ground swimming pools.
In an unprotected sector, if it remains less than three months, no action is necessary.