The utilisation of natural airflow for ventilation provides architectural possibilities. This was expressed by Juan Lucas Young at Sauerbruch Hutton Architects, the project architect for the GSW Headquarters in Berlin:

“In a way one thing led to the other. At some point the ventilation was pulling the idea of the high-rise, but the high-rise came also and helped create the ventilation concept. They where somehow two things that came together”.

Ventilation of buildings can very roughly be simplified as 1) getting fresh air into the building from the outside, 2) directing the air through the interiors to provide them with fresh air and to pick up heat and pollutants on its way, and finally 3) getting the exhaust air out of the building. The three points are useful when attempting to sort out the architectural possibilities associated with natural ventilation.

The first and the third point; getting air into and out of the building, are manifested in ventilation openings in the building envelope (fagade and roof). These can be accentuated in various ways, and they can be associated with various characteristic elements like e. g. a wind scoop and a double facade. The design and shaping of ventilation openings can
represent an architectural possibility, but they can also be a challenge or a limitation for some designs. Commonly, the ventilation openings are very pronounced in the architectural expression of the building due to their location and size, especially those in the fagade and in some cases also those on the roof. They are by implication considered as an important architectural element. The building can further be shaped or designed in order to increase over and under pressure at designated locations on the building envelope where the ventilation openings are located. The administration building for the Deutsche Messe AG in Hanover, Germany is an example of this where a conscious build up of volumes increases the driving pressure created by wind at the areas in the building envelope where the ventilation openings are placed. The curved facades of both the Deutsche Post Headquarters in Bonn, Germany and the MDR-Zentrale in Leipzig, Germany are examples of the same where the building by virtue of its shape influences the driving pressure derived from wind. It is, however, most common that the characteristic ventilation elements, rather than the whole building, are designed to increase the driving pressure. The wing of the GSW Headquarters, the wind cowls of the B&O Headquarters and the wind towers of IONICA Headquarters in Cambridge, UK are examples of that.

The second point, directing the airflow through the interiors from the inlet opening(s) to the outlet opening(s), represents a great design challenge as the desire for minimal pressure drop for optimal utilisation of the natural driving pressure (from the ventilation point of view) can conflict with the functional needs and requirements of the users of the building. This especially applies for natural ventilation concepts based on cross — and stack ventilation principles where the air paths are much longer than those in single-sided ventilation principles. This challenge involves at the same time substantial architectural possibilities for the organisation and the shaping of the interior spaces in particular, and the overall shaping of the building in general. The possibilities for the interior spaces derive from the fact that the various rooms form links in the "chain of the airflow path”, stretching from inlet to outlet. Depending on a room’s location in the airflow path, different size, proportion, floor-to-ceiling height and so forth is desired from a ventilation point of view. The architectural possibilities that can be derived from this comprise issues related to spatial experience and quality in the interior spaces (volumes, proportions, floor-to-ceiling height) as well as the spatial connections and rhythm of spaces with differing expressions and qualities along the airflow path.

The ventilation principle and the organization of the interior spaces produce new reasons as well as arguments for buildings to assume certain forms and proportions (e. g. GSW Headquarters, B&O Headquarters, Commerzbank Headquarters, Deutsche Post Headquarters and Jean Marie Cultural Centre). The shape of most naturally ventilated buildings have in common that they can utilise daylight in practically all interior spaces, and accommodate view to and contact to the exterior from virtually every spot inside the building. The headquarters of GSW and B&O are prime examples of that. The avoidance of large ventilation plants with belonging components and vertical and horizontal ductworks may in itself result in architectural possibilities and a greater freedom in the design[19].