It is enough to observe some of the most pulsating cities today to see that entrepreneurial creativity seems to be inversely proportional to available urban space. Proof of this are the various projects around the world with new ways of making better use of the rooftops of buildings or raised slabs.

Some of them add to the economic use of rooftop slabs the ambitious proposal to rethink the function of buildings in the urban context. This is the case of the Bosco Verticale in Milan, a building covered in trees that, in addition to serving as an architectural reference, functions as a natural air-conditioner, reducing the temperature of the units by two to three degrees celsius. In the same area, green spaces, top floors of buildings intended for agriculture, forests, and living spaces emerge in an attempt to combat current problems such as pollution and global warming. There are countless companies that install and operate urban farms on top of buildings in cities like Boston and Chicago (USA), Toronto (Canada), Shanghai (China), and Rotterdam (Holland).

This idea for financing the green economy has also boosted the solar energy market. In New York, for example, where the public is sensitive to environmental issues, the high price of electricity, coupled with tax incentives and financing possibilities, has significantly increased the demand for solar panels in buildings, either individually or through the creation of solar condominiums for the production of alternative energy. Formats like these are present in large quantities, for example, in Los Angeles (USA), Maputo (Mozambique), and Hamburg (Germany).

Another sector in which the players are coordinating and that must undergo major transformations is urban air transport. Thanks to the relatively new phenomena of drone delivery, something that has hitherto been seen as futuristic is already happening in cities in China, and also in Helsinki (Finland) and Lugano (Switzerland). It is estimated that, in two to three years, such equipment will take the urban airspace of cities such as Los Angeles, London, and Singapore. Companies in the industry are investing hundreds of millions of dollars in building an infrastructure network of vertiports, drone landing sites on the tops of buildings in various cities around the world.

The demand has been so great that buildings reserve in advance their top floors for this purpose. The proposal of vertiports is to create a hub of connectivity between the area where they will be installed and the rest of the city. They will serve as logistics points for product distribution and reception of passengers and promise to add to the building a value that goes well beyond the use of the landing platform for the personal benefit of the building’s residents. Busy air traffic in cities seems to be a reality closer than one might think.

The above examples are proof of an increasingly disputed, and in that same measure, more valuable urban space. Giving a new economic use to a portion of a previously unused property, in addition to adding value to the property, intensifies the fulfillment of its social function as an integral part of an ordered city.

This concept is in no way alien to the Brazilian legal system, which, through Law No. 13,465/2017 (previously covered by Presidential Decree No. 759/2016), definitively regulated the property rights of top floors (slab right), a type of surface right intended to legalize irregular settlements due to the numerous cases of informal housing in urban centers in Brazil and the evident need to attribute value to these properties as a measure to integrate them into the formal city.

The slab right imposes a in rem right to the level that puts over or under a base construction by opening a separate enrollment in the real estate registry, which allows the owner of the slab, for example, to offer it as a guarantee for a line of credit. The new property will have an individualized registration with the city government and, with this, it must collect taxes and submit plans for municipal approval, thus becoming a computable area in the records of the municipality and subject to urban administrative rules and planning guidelines. Thus, due to its regularization, the new property-slab becomes more secure and has greater market value, generating a gain for all agents involved: the owner/taxpayer, the municipal power, and society as a whole.

Excepting here the possible legal comments on the system, the slab right serves as a tool for the owner of a property to individualize its slab for use, without the law restricting the form or purpose of that use. The legal provision also establishes that the owner may individualize the slab over its property, even when keeping the title thereto. So it is possible that the owner of the slab and the base-construction be the same person.

Now, would not the system also work as a way of generating value in the above examples of use? Would it be possible to think of the slab right as an accelerator of opportunities in this current scenario of new demands and dynamic solutions?

Undoubtedly, a great obstacle to bringing this into effect arises from the actual operation of the slab right. A priori, the slab must have access independent of the base construction, have its usage plan submitted for municipal approval, and its taxpayer individualized. For its institution, it also depends on the granting of a public deed, collection of transfer tax, and recording in the respective enrollment of the base-construction property. In the case of a recent creation, the real estate registrars still have little familiarity with them, in addition to divergent and non-consolidated understandings regarding the requirements for their registration, which gives rise to a subjective approach on the occasions in which slab rights are effectively created.

A long path still needs to be walked for the slab right to serve as an effective tool. Nevertheless, the creation of a law governing this modality alone evidences a change of mindset regarding the use of urban space and the importance of having this urban space be integrated into the formal city.

This approach is a no-return path. We live in the era of density, verticality, and growing concern with the sustainability of the urban environment. Enabling life in these centers necessarily requires meeting new demands, sometimes through innovative and multidisciplinary measures, which may be promoted to the status of "solutions" only when their implementation is economically viable. It is to be concluded that as important as thinking up solutions for the urban demands of the present time is the development of tools able to put into operation the model of the city that we want to build.