Treehouse Building Law & Permit
Welcome to the colourful grey area!
Legal situation, laws and local regulations for treehouse construction: When do I need a building permit? Can I build a treehouse in the forest? How big can my treehouse be in a town?
The term “treehouse” has hardly been mentioned in the legal codes so far, and is therefore considered a legal grey area – we show what matters in detail!
1. Do I need a building permit for my treehouse?
The building permission is “the official authorisation by the building supervisory authority to erect, alter or remove a building structure”.
Interesting for us are the “permission-free buildings”!
Whether a treehouse belongs to the “permit-free” or “permit-required” category depends on its size, use and the exact location.
No official building application – “permit-free”
Planning permission is usually not required for a small, private treehouse in a residential area which is used “primarily as a children’s playhouse”.
It should meet the following criteria:
- Construction on private property
- Playhouse character (uninsulated, no fixed sleeping places, no electricity, play elements such as swings & slide, etc.).
- Small footprint < 10 m²
- Sufficient distance from property line (e.g. Bavarian building regulations > 3m)
- Well hidden so that no neighbour can see it
- No interference with neighbours (view, noise, shade, etc.)
- No sealing of the ground surface (no foundation)
Official building application – “subject to approval”
If the treehouse is going to be used as “living space”, you should think about going to the municipality or the local building authority – ideally before you start building.
This applies to:
- Public buildings (treehouse rental, Air B’n’B, open to the public)
- Treehouses with residential character (insulated construction, beds and furnishings, electricity supply, sanitary facilities, toilet, heating, fireplace, kitchen, …)
- Gross room volume exceeded; e.g. Bavaria: building > 75 m³ gross room volume –> subject to approval according to BayBO
- Closely populated area
- Community gardens
- Rented properties
- Encroachment on neighbours (new visual contact, view, noise, …)
- Treehouse very close to property line / fence / neighbour
2. Regulations – what do I have to pay attention to in urban areas?
If you want to build your treehouse in your garden in a residential area, the development plan is important:
This contains the legally binding regulations of the respective municipality, e.g. roof shape, roof pitch, roof covering, railing height, building materials, building boundaries, colour design, permissible height, distance to the neighbouring property, …
The development plan can be viewed at the building regulations office, the municipal administration, the town planning department, and at many municipalities also online.
For large treehouses with residential character, we recommend that you inform yourself in detail about the local building regulations before building.
In most cases, the building application is similar to that for a regular garden house. Local architects and building companies can help you with the plans!
The gross volume of the treehouse [m³]
In many places, the decisive factor for planning permission is the so-called gross volume, that means the total size or volume of the treehouse.
You can see how this is calculated in the following example:
Wie unterschiedlich diese Bauvorschriften von Region zu Region sein können, zeigen wir dir exemplarisch an den Bundesländern von Deutschland:
Berlin, Saarland, Sachsen, Sachsen-Anhalt, Thüringen
Hamburg, Hessen, NRW
Berlin, Saarland, Sachsen, Sachsen-Anhalt, Thüringen
Hamburg, Hessen, NRW
If the volume of the treehouse is below the limit, the building project falls into the category “permit-free”.
However, this does not mean that construction can automatically begin:
As a rule, only smaller ancillary structures are exempt from approval, e.g. garden houses, children’s playhouses, carports, tents, temporary structures.
Residential complexes and obvious recreation rooms are still subject to approval. The residential character is created e.g. by fireplaces, fixed sleeping places, heating and sanitary facilities, water and electricity connections, hairdresser’s bonnet, Backstreet Boys posters, …
3. Attention in extra-urban areas
Besides our residential or settlement areas, there are also industrial and commercial areas. And there are agricultural areas and forests – these often border directly on the settlement areas – they form the outer (extra-urban) area!
In the total outer area, the building regulations are often very strict: special permits are only granted in isolated cases; illegally erected treehouses can be reported and in most cases have to be dismantled again – no matter how beautiful they are!
The situation is different on the outskirts, i.e. on natural areas directly adjacent to the settlement. Here, depending on the region, the authorities are often more open-minded:
In the case of treehouse hotels that promote local tourism, they are accommodating.
They also turn a blind eye to the odd private project.
You can see whether your tree is in a settlement area or in an outdoor area in the “land use plan” – you can view this directly at the municipality and the public building authority.
Are small hiding places and children’s treehouses allowed in the forest?
Outdoor area or not – if it’s up to us: YES!
Every adventure needs its place!
Keep building your hovels and board shacks in the forest! Create magical places where family and friends can come together and have a good time! What could be better?
Respect nature: don’t drag loads of building materials and rubbish into the forest. Use ropes instead of nails and respect the trees. Respect the forest dwellers and their peace and quiet as well as the foresters and landowners.
4. Our recommendation regarding “Planning permission for building a treehouse”
Building a treehouse is still a legal grey area.
If you build a small, hidden children’s playhouse, this is roughly the same as building a garden shed in terms of building law – no big deal, most people just build without a permit!
For larger projects (with a tendency to require permission), take your ideas and plans to the building authorities, or use the expertise of a local architect or building contractor.
Again, don’t panic, in our experience there is always a tree house fan or two in the community. The better prepared you are, the easier it will be to convince the authorities. You should present the following information:
- Use of the tree house (playhouse, office, sauna, …)
- Equipment (sanitary facilities, sleeping place, stove, …)
- Size (volume, ground plan)
- Exact plan of tree house (windows, roof shape, material, …)
- Location and orientation in the plot (ground plan, distance to neighbours)
- Height in tree and height of roof ridge (highest point)
- Fixing technique & statics (just use our website;)
Involve your neighbours – where there’s no plaintiff, there’s no judge!
In our experience, the most important thing (in such a legal situation) is that you inform all concerned about your building project and the consequences. As soon as your neighbours are affected in any way:
- Tell them about your treehouse project early on.
- Show them the final designs and dimensions of the project.
- and explain to them all the consequences of the new treehouse (children playing loudly, new eye contact, view when the tree is not in leaf in winter, new shade from the tree house, …).
This might save you and your neighbours some trouble!
By the way: Tenants are not allowed to build a treehouse without the landlord’s consent!