Garden shed: When do you need a building permit?

Whether you need a building permit for your garden shed depends mostly on its gross volume (Brutto-Rauminhalt) and your federal state. Many garden sheds are permit-free (verfahrensfrei) if they stay below the cubic-metre limit of the state building code and have no habitable rooms, toilets, or fireplaces. But permit-free does not mean rule-free. Setback areas and the development plan still apply.

What counts as a garden shed?

In building law, a garden shed is an auxiliary building without habitable rooms. That means a tool shed, a storage room for the lawn mower and bikes, or a simple shelter for garden equipment. Exactly this use is the condition for being permit-free.

As soon as you want to use the building for living, sleeping, or as an office, it becomes a building with a habitable room. Then the permit exemption no longer applies, no matter how small the shed is. The same usually goes for adding a toilet or a fireplace such as a wood stove.

How large may a garden shed be without a permit?

Unlike a carport, what counts for a garden shed is not the floor area but the gross volume in cubic metres. It is measured as the enclosed volume based on the outer dimensions. The limits differ considerably by federal state. As a rough guide, as of 07/2026:

The other states are mostly in a similar range. The exact figures are in your state building code, and they can change. Important: almost everywhere the limit only applies if the shed has no habitable rooms, toilets, or fireplaces.

Why gross volume is often overestimated

Many people think in square metres and get it wrong. An example makes it clear: a shed of 3 m x 3 m floor area and 2.5 m height has a gross volume of about 22.5 m³. That fits under the limit in almost every state.

A larger shed of 5 m x 4 m and 3 m height, however, already reaches 60 m³. In Bavaria or NRW that would still be permit-free, in Baden-Württemberg or Hamburg it would not. So always measure the outer dimensions and calculate the full volume, including the roof.

Inner area or outer area: the decisive difference

The permit exemption usually only applies in the inner area (Innenbereich), meaning within a built-up part of town or within the scope of a development plan (Bebauungsplan). If your plot lies in the outer area (Außenbereich), for example at the edge of the village, on a meadow, or in a weekend-home zone, the rules are much stricter. There even small garden sheds usually need a permit, and often building is not allowed at all.

If you are not sure how your plot is classified, clarify that point first. It decides everything else.

Permit-free does not mean rule-free

Even without a building application you have to comply with the substantive rules. This is overlooked especially often with garden sheds:

• The development plan can restrict auxiliary buildings to certain areas or ban them in the front garden.
• The setback areas to your neighbour still apply. In many states a small building without habitable rooms may go on the boundary under conditions, but those conditions are narrow and differ by state.
• Local design by-laws can prescribe material, colour, or roof shape.
• In allotment gardens, the federal allotment garden act additionally applies, with its own size limit for garden houses.

So a shed can be permit-free under the state building code and still be inadmissible because it violates the development plan or the setback rules. In the worst case you face demolition.

When do you definitely need a permit?

In these cases you should assume a permit is required, or at least ask the building authority:

• The shed is meant to get a habitable room, for example as a guest room, sauna, or home office.
• A toilet or a fireplace is planned inside.
• The gross volume exceeds your state's limit.
• The plot lies in the outer area.
• The shed is meant to go right on the boundary, where a garage or another shed already stands.

Frequently asked questions

May I sleep in a permit-free garden shed? No. A permit-free shed may not have habitable rooms. Sleeping, living, and permanent working turn it into a building that needs a permit.

Does the foundation matter for the permit question? The cubic-metre limit refers to the building itself. A foundation makes the shed permanent and underlines its structural character. A simple foundation usually does not change the permit exemption, as long as the volume limit is met.

Does the neighbour have to agree? For a permit-free shed with sufficient boundary distance you need no consent. It gets critical with boundary construction. Then your state's setback rules apply, and coordinating with the neighbour saves you a lot of trouble.

Conclusion

Most classic garden and storage sheds can be built without a building application if they stay below the cubic-metre limit and are pure storage rooms. The pitfalls lie elsewhere: habitable rooms, the outer area, the development plan, and the boundary distance. Clarify exactly these points before you buy, not after.

Check your project in a few minutes with BauErlaubt and find out which rules apply to your garden shed in your federal state: Start the free pre-check.

This article is for general information only. It does not replace legal advice or a binding statement from the competent building authority.