Treehouse Building Permit & Regulations
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Legal situation, planning permission and local regulations for treehouse constructions: When do I need a building permit? Can I build a treehouse in my own forest? How big can a treehouse for children in my backyard be?
The term “treehouse” has hardly been mentioned in the legal codes so far, and is therefore considered a legal grey area. As professional treehouse builders, we show you what matters in practice and what “tricks” you can use to keep your treehouse permit-free.
1. Do I need a building permit for my treehouse?
Definition of building permit: “The building permission is the official approval of the building supervisory authority for the erection, alteration or removal of a built structure.”
Admittedly, a treehouse is strictly speaking a “built structure” and would thus fall into the category of “outbuildings”, like a garden shed, gazebo, garden sauna, construction trailer or Tiny House.
But fortunately, the treehouse is still something special:
- We build high into the tree and use it as a support.
- We don’t seal any floor space.
- Ideally, we need neither stilts nor point foundations, i.e. the natural soil remains untouched.
- The house blends harmoniously into nature without being perceived as a disturbing object.
Since we would like to save ourselves the building permit, the costs and the earthly effort, we are particularly interested in “buildings without permits or procedures”! Whether a treehouse falls into this category depends on its size, use and exact location.
No official building permission – “permit free”
No building permission is usually required for a small treehouse in one’s own garden 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 (play elements such as swing & slide, climbing wall, …).
- No residential character (not insulated, no fixed sleeping places, no electricity, …).
- Small footprint < 10 m².
- No sealing of the ground (no foundation).
- Sufficient distance to the property boundary (e.g. Bavarian building regulations > 3 m).
- Well hidden so that no neighbour can see it.
- No interference with neighbours (view, noise, shade, …).
In some places, it should also be possible to build a treehouse in an allotment garden site. Here, for example according to the German “Federal Allotment Garden Law” (BKleinGG), structures up to 24 m² can be erected without permission – so why not!
Official building permission – “subject to approval”
If the treehouse is to be used as a “lounge or living space”, it is worth considering going to the municipality or the building authority – ideally before construction begins.
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. Germany: building > 75 m³ gross room volume –> subject to approval according to BayBO)
- Closely populated area, many neighbours
- Adverse effect on neighbours (new visual contact, view, noise, …)
- Treehouse very close to the property boundary
- Rented property
- In some places local tree protection ordinances or monument protection apply!
2. Regulations – Treehouse Construction in Residential Areas
If you want to build your treehouse in your garden in a residential area, the development plan is important: it contains the legally binding regulations of the respective municipality, e.g. roof shape, roof pitch, roof covering, railing height, building materials, building limits, colour design, permissible height and distance to the neighbouring property. The development plan can be viewed at the building regulations office, the municipal administration, the urban planning department and, in many municipalities, online.
How may I attach my treehouse to the tree?
There are still no standards and construction regulations on how to attach the treehouse to the tree. However, some cities and municipalities have their own tree protection ordinances, according to which, for example, trees with a circumference of > 80 cm are subject to special protection.
For larger treehouses with a 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 shed, pavilion or tool shed.
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:
We will show you how different these building regulations can be from region to region, using the federal states of Germany as an example:
"Permit-free" residential area
Berlin, Saarland, Saxony, Saxony-Anhalt, Thuringia
Hamburg, Hesse, NRW
Baden-Wuerttemberg, Lower Saxony
"Permit-free" outdoor area
Berlin, Saarland, Saxony, Saxony-Anhalt, Thuringia
Hamburg, Hesse, NRW
Baden-Wuerttemberg, Lower Saxony
If the volume of the treehouse is below the limit, the building project falls into the category “permit-free”.
This is just one example for Germany! In other countries, too, building laws vary greatly depending on the individual state and municipality – get informed!
However, staying below the legal volume does not mean that you are automatically allowed to build everything you can think of.
As a rule, only small and simple structures are permit-free, e.g. garden houses, children’s playhouses, carports, tents, temporary structures.
Residential treehouses and obvious living rooms are still subject to permission. 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, …
Note: Tenants may not build a treehouse without the landlord’s consent.
3. How much does a building application for a treehouse cost?
The costs for a building permit also vary from municipality to municipality and from country to country, but they are much lower than for a normal residential building. They usually depend on the size of the house and the gross material costs and range between 0.5 and 1 %. This then looks like this, for example:
(enclosed space m³ x construction value €/m³) × 0.5
In addition, there may be the costs for a “qualified design consultant” (local architect or civil engineer), which is required in some places. In most cases, however, the building application can be prepared informally by yourself with the following information:
- building material and type of construction of the treehouse
- exact size (floor plan with dimensions)
- planned use and equipment
- location on the property (parcel number)
4. Attention – Treehouse Building 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- or 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 demolished again – no matter how beautiful they are!
The situation is different on the close outskirts, i.e. on natural areas directly adjacent to the settlement. Here, depending on the region, the authorities are often more open-minded:
We often have experienced that municipalities are accommodating, especially with treehouse hotels that promote local tourism. They also might turn a blind eye to the private project if you have some contact in the local building scene.
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 children’s treehouses and small hideaways allowed in the forest?
Outdoor area or not – if it’s up to us: YES! Every adventure needs its place!
If possible, it is of course better to build the treehouse in your own forest, because there you already know the forester, the farmers and the neighbours.
Keep building your hovels and children’s playhouses in the forest! Create magical places where family and friends can meet and have a good time! What could be more beautiful!
Take care of nature: don’t drag loads of building materials and rubbish into the forest. Use ropes instead of nails and be considerate of the trees. Respect the forest dwellers and their peace and quiet as well as the instructions of foresters and landowners.
5. Our recommendation regarding “Official permission for treehouses”
Building treehouses is still a legal grey area in most countries.
If you build a small playhouse or hidden children’s treehouse, this is roughly the same as building a garden shed in terms of building law – no problem, most people simply build without a permit!
For larger projects (tendency “subject to approval”), it is best to go to the building authority with your ideas and plans. There you can get clarification with a free preliminary building application. Don’t panic, in our experience there is always a treehouse fan or two in the community. The better prepared you are, the easier it will be to convince the authorities of your project.
Powerful arguments, constructive know-how and sustainable fixing techniques can be found in abundance on our website:
- Use of the treehouse (playhouse, office, sauna, …)
- Exact plan of treehouse (building material, windows, roof shape, …)
- Equipment (sanitary facilities, sleeping place, stove, …)
- Size and statics (volume, ground plan)
- Location and orientation in the plot (ground plan, distance to neighbours)
- Height in the tree and height of roof ridge (highest point)
- Sustainable mounting technique
Involve your neighbours – Where there’s no plaintiff, there’s no judge!
In our experience, the most important thing (in such a diffuse legal situation) is that you inform everyone concerned about your building project and its effects.
As soon as your neighbours are affected in any way:
- inform them about your treehouse project at an early stage.
- show them the final plans and dimensions of the project.
- and inform them about all effects of the new treehouse (children playing loudly, new visual contact, view when the tree is not in leaf in winter, shadows cast by the treehouse, …).
This way you will save yourself and your neighbours potential trouble!