Greece’s top court rules on underground construction and digital building permits

The ruling comes at a time when case law concerning the planning incentives introduced by the New Building Regulation (NOK) has affected the design of construction projects, creating uncertainty for property owners, developers and investors.

However, the country’s highest administrative court has left another critical issue unresolved: which building coefficient takes precedence when the provisions of older General Urban Plans differ from the coefficients established through presidential decrees.

Hotel Development Near the Acropolis at the Centre of the Case

The ruling was issued in the context of an appeal against a building permit for the construction of a seven-storey hotel in the Makrygianni district, near the Acropolis.

The appellants challenged the legality of several provisions included in the permit, including the construction of mezzanines that are excluded from the building coefficient calculation and the possibility of extending underground spaces beyond the footprint of the above-ground building.

Regarding the mezzanines, the court followed the established case law of the Council of State’s Plenary Session, which has ruled that the relevant planning incentive is unconstitutional, proceeding with the partial annulment of the building permit.

By contrast, concerning underground spaces, the court ruled that their extension beyond the building’s footprint, subject to the conditions set out in Article 17(6) of the New Building Regulation, does not violate Article 24 of the Greek Constitution.

What Can Be Built Beneath a Property

The Council of State’s ruling confirms that underground spaces may, under specific conditions, occupy a larger surface area than the above-ground building itself.

This provision is particularly important for the construction of underground parking facilities, storage areas, mechanical installations and other permitted uses.

For new developments, making use of part of the uncovered area of a plot at basement level can improve building functionality and reduce the need to accommodate ancillary facilities on above-ground floors.

The court also took into consideration that similar provisions allowing the expansion of underground spaces, subject to certain conditions, were already included in previous planning legislation.

The ruling does not, however, permit unrestricted excavation of an entire plot. Restrictions concerning building coverage, landscaping and the protection of natural ground remain in force, alongside the specific building regulations applicable in each area.

The Kifissia Exception

Decision 805/2026 should be considered alongside Decision 2035/2025, which concerned the traditional part of Kifissia.

In the latter case, the Council of State ruled that the area’s special urban planning and protection framework did not allow underground spaces to extend beyond the footprint of above-ground buildings.

The distinction is linked to the protection of mature vegetation and the area’s distinctive character. Consequently, the constitutional validity of the general provision under the New Building Regulation does not override stricter restrictions applicable in designated areas.

Electronic Building Permits Also Deemed Constitutional

The same ruling confirms the constitutionality of the electronic building permit issuance system introduced under Law 4495/2017.

Depending on the permit category, the system allows building permits to be issued automatically through the e-Adeies platform, under the responsibility of private-sector engineers and without requiring a full prior review of the application file by the relevant Building Authority.

The appellants argued that this procedure limits state oversight of construction activity. The Council of State rejected this argument, finding that the legislative framework provides adequate mechanisms to ensure compliance with planning regulations.

These mechanisms include random inspections of building permits and checks carried out during construction works by certified Building Inspectors. The current framework requires random inspections covering at least 30% of building permits issued during each six-month period.

At the same time, the court confirmed that an electronically issued building permit retains its status as an administrative act and remains subject to judicial review.

This finding limits the scope for challenging a permit solely on the grounds that it was issued electronically. It does not, however, prevent its annulment where specific urban planning regulations have been breached.