How significant is he façade or façade system for revitalisation?
Meyer: For revitalsition projects, the first thing we do is to check that the axial grid is economically efficient. We analyse the functionality of the building and optimise it. The seestern project has not just been given a facelift; it has been completely redesigned from the inside out. To increase the office functionality, we have reduced the existing fit-out grid from 1.80 m to 1.30 m. the fit-out grid no longer matches the construction grid, but the offices are more compact, which makes marketing of the space much more effective.
Schmitz- Morkramer:Another important factor is energy efficiency. The old 1970s façade did not meet current building physics requirements. Not only was there no insulation, but the solar shading and the oversized, unwieldy windows were very outdated. Revitalisation does, of course, involve modernising the exterior shell using the latest energy saving concepts. On the one hand, it is important to let plenty of light into the building, but you also need to create a skin that protects against excess solar radiation and heat.

How did this characteristic rhythmic façade come about?
Schmitz- Morkramer: For reasons of flexibility and efficiency, it is sufficient if only every other window vent can be opened for ventilation. This was how we designed the theme of the façade. We developed two units, one with fixed glazing and one with an opening vent in an Alucubond frame. These units are alternated and define the structure of the façade.

Where did the colour concept fort he facade come from? What is the significance of the colour of the outer frames of the window?
Schmitz- Morkramer: We wanted to create a strong light-dark contrast. We wanted the white Alucobond façade to stand out against the dark surface of the glazing like a structural framework. Glass usually appears dark during the day anyway, particularly as, for energy reasons, we have used solar shading glazing which has a light grey tint and intensifies the contrast. We also chose dark grey as the colour for the outer frames so that they appear to form a single unit together with the glass. The solar shading is also in this colour.

The appearance of the façade with the alternating window sizes suggests a complex structure. But in fact both are based on a single base unit. Can you explain that in a bit more detail?
Schmitz- Morkramer: There are two façade units with a grid dimension of 1.30 m that have the same base structure. One is he unit with the fixed glazing over the whole surface; the other is the opening vent in a closed frame. The substructure for his module consists of brackets that are attached to the ceilings. The prefabricated façade units are installed in this substructure. The next step is to fix the Alucobond cladding from outside, both for the ceilings and the window units. The interior of the façade has homogeneous metal cladding, and a channel integrated flush in the façade carries the data cables and the electricity supply to the offices. The particular quality of the façade comes from the fact that it is created entirely from standard products yet still has extreme contouring and plasticity. It is very economically efficient and was constructed very quickly. We finished one floor of the façade in one week.

Is a white façade not very high maintenance?
Meyer: The white façade must have optimum drainage in order to keep it looking attractive over a long period of time. Drainage spouts must be avoided. In the Seestern building, rainwater runs from the window stills inside and drips down in the cavity between the thermal insulation and the Alucubond outer skin.

You modified the existing core structure of the building when designing the interior. This improves the building. Why?
Schmitz- Morkramer: The core was originally only 4 m wide throughout the entire 50 x 22 m building. We extended the core by 8 m in the centre, and supported it at the ends. This allowed us to create additional, attractiveoffices. The core is not actually any bigger, but its dimensions have been changed. This also allowed us to install access airlocks that are a legal requirement for an enclosed staircase. These airlocks were necessary because we had removed an external emergency staircase during the revitalisation. This change reduced the depth of the offices from 8 m to the standard 6 m plus the with of the corridor, and we were also able to gain valuable open areas at the end of the building. Only the areas of the core that were badly lit anyway have been lost, and the same at the same time we have gained high-quality offices space at the façade. As part of a project study, we were able to prove that the workplace efficiency of the building could be increased by 30 % by reducing the fit-out grid from 1.80 m to 1.30 m and optimising the floor plan design. There is therefore barely anything to distinguish this revitalised building from a brand new development. Potential tenants were very impressed and our client was able to rent out the entire building within a very short space of time. A perfect example of a successful revitalisation.

The architects Holger Meyer and Caspar Schmitz- Morkramer talked to Robert Mehl, Aachen
http://www.schueco-profile.de