Property of Public Interest

The Property of Public Interest (abbreviated IIP) is one of the three grades of classification provided for immovable cultural heritage in Portugal. It sits between the highest grade — the National Monument — and the more localised level of the Property of Municipal Interest, constituting, in practice, the most numerous category among the country’s classified properties.

Legal definition

The framework in force is established by Law No. 107/2001, of 8 September, the so-called basic law on cultural heritage. According to its provisions, “a property is considered to be of public interest when its protection and enhancement still represent a cultural value of national importance, but for which the protection regime inherent in classification as being of national interest would prove disproportionate”.

The decisive criterion is therefore one of proportionality: the property possesses unquestionable relevance on the scale of the Nation, but the application of the more demanding regime — reserved for National Monuments — would be excessive in view of its specific characteristics. This is a qualitative distinction as to the regime of guardianship, and not a mere gradation of artistic or historical merit.

The IIP is not a “lesser national monument”: it is a recognition of national value adjusted to a protection regime deemed appropriate and feasible for that specific property.

As with the other grades, a Property of Public Interest may fall within any one of the three categories provided for under international law — monument, ensemble or site — as defined in the Granada Convention and in the tradition of heritage conventions. An IIP may thus be an isolated building, a coherent urban or rural settlement, or a space of human or mixed origin.

Historical roots of the designation

The figure of the property of public interest predates the current law. Between 1926 and 1932, a set of legal instruments created for the first time the possibility of classifying architectural and archaeological properties at levels below that of national monument, also establishing the protection of properties in the process of classification and the demarcation of protection zones. Decree No. 20:985, of 7 March 1932, which reorganised the Fine Arts services, consolidated the category, deepening the notion of safeguarding the surroundings of classified properties.

This evolution unfolded, over decades, under the guardianship of the historical heritage institutions — from the now-defunct Directorate-General for National Buildings and Monuments, responsible for a large part of the twentieth-century classifications, to IPPAR and IGESPAR, up to the present-day Directorate-General for Cultural Heritage.

Procedure and effects

Classification as an IIP results from an administrative classification procedure that may be initiated by any interested party, conducted by the competent services — the DGPC or the regional directorates for culture — and concluded by governmental decree. It forms part of the heritage classification system that structures the safeguarding of the built fabric in Portugal.

Significant legal effects flow from classification: the property becomes subject to a regime of guardianship that constrains works, alterations and disposals, and a special protection zone may also be established to regulate the surrounding area. By virtue of these effects, the registration of a property as an IIP is recorded in the official heritage inventories and databases, ensuring publicity and continuity of protection. The great majority of the thousands of classified properties in Portugal belong precisely to this grade, which makes the IIP the most widespread instrument of formal recognition of the cultural value of the nation’s built heritage.