The church authorities were planning a newbuild to house their offices, apartments, a cafe and seminar rooms on a site owned by the Evangelical Parish of St Cornelius on the northern edge of the Schillerpark. The client attached great importance to sustainability both in the construction and in the operation of the building, to be constructed alongside its church and kindergarten.

The result is a pioneering structure, the first in Germany to be built on the method 22·26, that guarantees a comfortable temperature of 22 to 26ºC. Rather than complex service plant, the Kornelius Forum relies for its energy efficiency on the tried-and-tested tools of architecture: solid walls and floors to provide insulation and thermal storage mass. The careful balancing of window-to-wall ratio, proportions, materials and light give optimum lighting and heating conditions. At its heart is an operating system that controls the temperature throughout the building.

A stand-alone structure

Set back from the street lines of the adjacent listed buildings in the English Quarter, its stand-alone position is underscored by a slight rotation of its longitudinal axis and the clear order and rhythm of open and closed facade surfaces.

Technical services have been kept to a minimum thanks to the innovative 22·26 construction method. Summer cooling becomes entirely redundant while heating is required on the residential floor only. The external walls are made of solid blockwork and finished in a red-coloured textured render using traditional craft techniques. Narrow, floor-to-ceiling windows set flush with the interior walls give the building a sculptural quality and a clear identity. They also provide maximum shade and minimal summer heat input.

Distinct characters, significant functional flexibility

Three separate entrances for the apartments, office and cafe each have their own character; vertical access is via a staircase and lifts. Solid reinforced concrete floor slabs fulfil the storage function required for the method 22·26, furnish an almost column-free floor plan and so maximum flexibility of use.

The new build replaces the previous parish hall, which was much in need of renovation. The re-siting of the building increases the size of the external play area attached to the kindergarten and creates space for a new public church garden at the Kornelius Forum.