The fact that plots of land that have been designated as building land for many years remain undeveloped is not a new phenomenon in Austria. A current example can be found in the municipality of Umhausen in the Tyrolean district of Imst: more than 15 years ago, several areas were designated as building land, but have not been developed to this day. In order to counteract this building land surplus and the associated price increases, more and more municipalities are establishing so-called building prohibition zones. The aim of such “building prohibition zones” is to subject unused but already designated building land to active control by the municipality. The municipal council of Umhausen has also defined such “building prohibition zones” in its 2020 local spatial planning concept.

A landowner affected by this decision subsequently challenged the rejection of her building application. The Tyrol Provincial Administrative Court (“LVwG”) referred the case to the Constitutional Court (“VfGH”). However, the latter saw no reason to repeal the underlying regulations.

Background and initial proceedings

In 2018, the complainant acquired a plot of land that was designated as building land – residential area at that time. Subsequently, the municipal council of Umhausen decided to designate this plot of land as a “no-build zone” in accordance with Section 35 (2) of the Tyrolean Spatial Planning Act 2016 (“TROG 2016”), which was in force at the time the contested regulations were issued. This designation means that, despite the land still being zoned for residential development, only construction projects that could also be built in open countryside are permitted on the land in question. The landowner's application for a building permit for a residential building was subsequently rejected on the grounds that it was a “no-build zone”.

The proceedings therefore focus on the question of whether the designation of a building prohibition zone under TROG 2016 was a permissible means of dealing with a regional surplus of building land. The LVwG, which was subsequently called upon, expressed concerns about the legality of the underlying regulations and, on its own initiative, filed a motion to initiate a legislative review procedure with the VfGH and to repeal the amendment to the local spatial planning concept and the zoning plan of the municipality of Umhausen with regard to the property in question as unlawful.

The concerns of the LVwG

In the opinion of the LVwG, both the updating of the regional planning concept and the amendment of the zoning plan – in particular the designation of “no-build zones” – were carried out without sufficient grounds. Nor was there any differentiated examination of the specific circumstances of the properties concerned. In addition, the indefinite designation as a “no-build zone” was effectively equivalent to a rezoning without the owners concerned being granted compensation. In the opinion of the LVwG, this constituted a disproportionate interference with the constitutionally guaranteed right to property. Furthermore, the LVwG stated that neither the regional planning concept nor the zoning plan defined clear criteria for when there was a “need” to lift the building prohibition zone.

Key statements of the Constitutional Court

The Constitutional Court dismissed the LVwG's application as unfounded (Constitutional Court 23 September 2025, V 81-82/2025). In the opinion of the Constitutional Court, the municipality had carried out basic research in accordance with the legal requirements and identified a significant surplus of building land of around 19 hectares in the residential area. Contrary to the concerns of the LVwG Tirol, however, the local spatial planning concept specifies the conditions under which the “building ban” is to be lifted. The local spatial planning concept stipulates that land may be developed if further conditions are met. The plan distinguishes between several categories of building prohibition zones, each with graduated requirements – from a simple proof of need (ZV1) to proven suitability for building, development and land structure (ZV3). This differentiated regulation makes it clear that the municipality made appropriate use of its planning discretion.

The Constitutional Court did not see any constitutionally inadmissible rezoning raised by the Administrative Court. Rather, it considered the measure to be a permissible, proportionate control instrument. The public interest in reducing the considerable surplus of building land justified the interference with property rights. However, it was crucial that owners had the opportunity to apply for the “building ban” to be lifted if there was a specific need. According to the Constitutional Court, it was precisely this possibility that ensured the proportionality of the regulation.

Significance beyond the individual case?

The admissibility of the so-called “building prohibition zone”, which at first glance appears to have been confirmed by the Constitutional Court, and its portrayal in the media as a far-reaching, generally binding or even “fundamental” decision by the Constitutional Court, are put into perspective upon closer examination. The Constitutional Court did indeed rule that the designation of the “building prohibition zone” to reduce the surplus of building land was in the public interest. However, according to the legal assessment, the proportionality of the measures (and thus also their admissibility) results in particular from the mandatory mechanism for their repeal:

The designation – and thus the associated “building ban” – must be lifted as soon as the conditions defined in the relevant regulations are met and there is a specific need for use in accordance with the designation. The spatial planning concept of the municipality concerned provided clear criteria for this, such as proof of need, proof of suitability for building land or ensuring transport access. This specific design strikes an appropriate balance between the public interest (in particular the reduction of building land surpluses) and the interests of the owners.

Furthermore, the principles applied by the Constitutional Court in its decision are by no means new, but are consistent with its existing case law on the relationship between zoning plans and development plans. If the regulator stipulates in the zoning plan that a development plan must be adopted, this results – as long as no such plan has been adopted – in an inadmissible de facto building ban for the property in question, according to the case law of the Constitutional Court. The same applies, logically, to the lifting of a building ban zone: if the conditions for lifting the ban are met – for example, by proving a specific need – the designation must be lifted. In addition, for a “building prohibition area” to be constitutional, the possibility of providing the necessary proof of need must also be open to third parties (i.e. without the direct involvement of the municipality). Otherwise, the aforementioned de facto permanent building ban would arise, which in this form could not be considered proportionate within the meaning of the constitutional guarantee of property rights.

The specific case must also be assessed against this background. The Constitutional Court's finding that the relevant regulation is constitutional does not mean that a specific, demonstrable need on the part of the property owners is ruled out. On the contrary, it is precisely the possibility of obtaining the removal of the designation as a “no-build zone” by proving such a need that justifies the constitutionality of the regulation.

The “building prohibition zone” remains a temporary and dynamic instrument of spatial planning that enables situation-appropriate control, but is not a permanent means of restricting property rights. In its decision, the Constitutional Court does not confirm a new fundamental understanding, but rather clarifies the already known constitutional balance between public planning interests and individual property rights.

Conclusion

On closer inspection, the Constitutional Court's ruling that the current “building ban zone” is constitutional does not represent a far-reaching or fundamentally new decision. Rather, it is a consistent continuation of previous case law. The decisive factor is that the Constitutional Court recognises the proportionality – and thus also the admissibility – of the measure in the mechanism provided for its repeal. This does not therefore represent a “change of course” for Tyrolean spatial planning policy, as has been suggested in some media reports. Rather, it remains the case that building prohibition zones can only be maintained if they are based on careful fundamental research, a comprehensible needs assessment and proportionate design.

In practice, this means (as before) that local authorities must document clearly and comprehensively the factual and legal basis for their actions when issuing relevant regulations. Even if the designation of a “no-build zone” may be in the public interest, it must be lifted as soon as a concrete need for a designated use is demonstrated.

Landowners, in turn, should actively check whether the conditions for lifting the building ban zone are already in place and, if necessary, take appropriate steps with the local authority. In this regard, the Freedom of Information Act may also offer a way of enquiring about the necessary conditions and their occurrence at the local authority.