According to current legislation, you can build a tree house in Italy, and there are a number of examples, both for residential and tourist use; provided that you turn to specialized companies that know how to deal with the design, construction, and bureaucratic procedures.
We summarize in brief the issues that these companies must address, to carry out the work in full compliance with the law, and the related bureaucratic procedures.
Is it possible to build a tree house?
It depends on the town's land-use plan. The building is governed by the Consolidated Law on Construction (Italian Presidential Decree 380/01) which delegates to the municipalities the powers in the field of urban planning regulation; therefore it is necessary to apply to the municipal technical office for a certificate stating that you are a member of the community and, if you are in a developable or rural area, we can speak directly with a technician of the municipality, who will communicate to us verbally the general orientation of the executive committee on the subject. If the opinion of the executive is favorable, it is possible to activate an administrative procedure to apply for a building permit, accompanied by a preliminary design.
Then, taking into account the comments of the municipal technician, it will be possible to draw up the final project in order to obtain permission. It is therefore only possible to build a tree house if written permission has been obtained from the relevant public authority.
Town plan: where can it be built?
Like any other construction it can only happen in the area category provided for in the town plan of the municipality to which it belongs. Both for tourist accommodation and for private use, it must be in a developable area, and the dimensions that can be constructed are defined in the municipal Territorial Development Plan.
Remit: who is entitled to draw up and sign the project of a tree house?
For buildings up to 2 floors, surveyors, architects and engineers may do so; clearly, whoever signs the project offers their skills as a guarantee, and they will have the same responsibility as for any other building.
What guarantees must they give the customer?
The guarantees are not established by law, but are set out explicitly in the contract governing the professional relationship between the client and the designer. Clients will include at the signing of the contract all the guarantees (agreed with the designer) they wish; designers will include in the same contract all the clauses and events of force majeure that exempt them from liability for accidents, damage or collapse. Since the tree is a living thing and constantly growing, it is very difficult for designers to provide guarantees that are durable enough over time: for this purpose they will in most cases include a maintenance contract, with an established expiry date.
How long do these guarantees remain valid?
The guarantees provided by designers have the validity agreed in the contract with the clients, with a further maintenance contract, especially for the first year, since in this period the plant and the structure settle the most. Generally, if there is no maintenance contract, the release occurs after one year.
How do producers protect themselves?
Just as architects use geologists to study the ground on which they will plant the foundations of their buildings, so builders of tree houses will use dendrologists; who, after the appropriate checks and using their knowledge (as well as specific tools), will draw up an expert report in which they will certify the state of health, growth and resistance of the tree, the individual branches of the plant and its capacity; dendrologists will also be required to protect themselves by explicitly excluding uncontrollable factors (lightning, fire, pest attacks..) and declaring the period of validity of this report.
Designers then protect their work by applying in the best possible way the best practices of their profession, and explicitly exclude force majeure events in the contract.
Is it possible to connect to the public service network (water, gas, electricity)?
Yes, if you have applied for and obtained planning permission:
Is it subject to the same standards as housing?
It depends on the building permit that has been requested: clearly not, if it is a tool shed; yes, if it is a dwelling and you intend to request habitability. Capacity: what is the minimum load and the maximum number of people it must be able to support?
The structure that will be built is dimensioned and designed so that it will be able to support the loads required by law for a floor (private dwelling: 300 kg/m²; with public access: 500 kg/m²); however, the tree itself may not be able to withstand this concentration of loads, in which case it will be necessary to make up for it with ground support elements, or by reducing the suspended surface. Designers/managers can however obtain more guarantees by specifying in the private contract between the parties, the maximum number of people who can stay in the structure at the same time.