Today, towers aren’t in the least indispensible. Nevertheless, they are an integral part of cityscapes worldwide. Every continent, every country, and even every town has its own culture and appropriates this urban morphology in a very different way. Towns haven’t developed at the same time or in the same way, which is why comparative studies are interesting. “The big cities of North America developed according to a grid system with a CBD identifiable by its verticality (skyscrapers) and sprawling residential suburbs (houses or small apartment blocks). In Europe, town centres are generally marked by religious, economic or political history; their urban fabric is mainly composed of buildings of average height whose facades are arranged in the form of narrow streets. South-American towns reflect an initial European Hispanic influence (high density, compactness, squares, etc.) followed by a development according to the model of North-American towns (vertical centre and sprawling suburb)”, Claire Saint-Pierre points out.

A closer look at the issue

In her thesis, Claire Saint-Pierre develops systemic tools to help define quality-based urban integration. She believes that a tower will have a greater chance of being integrated in the landscape if:
- the tower is multifunctional, and particularly if it has a good balance of facilities and services (housing/services or offices/services or housing/offices/services),
- the link with the public space is correctly dealt with (what is known as a ‘strong adherence to the public space’), particularly in conjunction with facilities,
- the project is in keeping with the transport networks (compatibility of the accessibility profile particular to the site and the mobility profile of the tower project),
- the impact on transport networks isn’t too great (no saturation or adaptation of the network),
- the architectural quality is elaborated in line with the surrounding buildings (integration with the landscape),
- careful consideration is given to the choice of height beforehand (choice of an assumed point of reference or moderate integration with the skyline),
- the effects of wind generated by the tower are limited (issue of the comfort of pedestrians around the tower),
- the solar angle is also limited (not too much shade for users of the surrounding buildings).
These criteria thus form the list of urban integration indicators that allow us to assess the urban performance of a tower, i.e. the quality of its integration in an urban environment.

Other than that, it is clear that a tower has pros and cons. Among the advantages, there is the profitability of the space (real estate and functional profitability), participation in urban centrality (concentration of activities, reduced travel), the possibility of integrating functionalities in the town centre, the symbolism and image the building may convey, or the diversity of scales it puts in perspective. Among the disadvantages are the construction costs and the high operating charges (due to the technologies required for the use of the tower), the impact on the users’ comfort (wind, shade cast, seclusion), and building difficulties (regulatory framework and functional specialisation of the investors).

The tower takes the pawn...

Decision-making is shared between the contracting authority (public or private investors), the body responsible for the urban regulations of the location where the tower will be built (authority or planner) and the project team (architects, town planners, engineers). It is proposed in the thesis that the processing method should take place beforehand, before knowing where the tower will be erected. It would allow various locations to be compared in order to choose the best one.  However, the proposed tool can also used throughout the process and can even be applied to a project for a tower that has already been built. “The choices and decisions concerning towers mustn’t be neglected because of their importance in terms of programming and funding, and because of their impact on the neighbourhood, town or city. The process of where a tower will be built must take place in the long term in a strategic and coordinated manner, in line with the development of transport”, explains Claire Saint-Pierre. She also adds: “If a town still doesn’t have any towers, the wisest place to erect the first vertical building is a mixed neighbourhood, close to a transport hub. It could also be built in a neighbourhood requiring urban renewal, but in this case, the tower must be one element among others within a broader urban project”.