The Tramdepot Bern is a strip-shaped hall with a glass and aluminum shell. With its

simple form, it succeeds in accommodating both the demands in terms of economy and organization as well as the external constraints of the tight, oblique-angled perimeter and giving it a concise form.

Staging

The expansion of the streetcar depot was conceived in several stages as early as the

2007 competition. With the expansion of the city‘s streetcar network, a denser timeta-

ble and new, longer streetcars, the need for depot capacity increased. Ten years after

completion of the first stage, construction work therefore began on the second stage.

This consists of expanding the depot from seven to a total of 15 sidings in the direction

of Bolligenstrasse. In a third stage - not yet scheduled - an extension of eight workshop

tracks is planned.

Construction

The extension will increase the span in the stabling area from 45 to 72 meters and

in the workshop area from 68 to 95 meters. The considerable span for the column-

free extension of the parking area was achieved with the gradual growth of the truss

girders, which then function according to the principle of crane jibs. The main forces

are absorbed by a middle row of columns, while the façade columns on the shorter

span side are transformed from compression members to tension members with the

extension.

Energy concept / sustainability

The extensive glazing in the truss levels of the beams and in the façades also ensu-

res optimum lighting conditions and allows the hall to be operated without a heating

system thanks to the solar radiation. To prevent overheating in summer, the SHEV flaps in the lower façade area (supply air) and in the high sheds (exhaust air) can be opened for night-time cooling. Rainwater is directed from the roof into the side gutters via the sloping surfaces of the longitudinal façades, from where it is fed into the washing system. A 3,600 m² photovoltaic system on the sloping roof surfaces complements the building‘s sustainability claim.

Building envelope

The geometry of the hall results from the operational need for a maximum, column-

free parking area. The roofing is supported over the entire length of the hall of around

200 meters by a shed roof structure made of steel trusses with spans of up to 90m

(stage 3). A single row of columns separates the parking area from the service area

with car wash, wheel processing area and maintenance building. The lifting doors of

the front façade with door heights of up to 10m open and close vertically. The inner and

outer supports are arranged in a V-shape for longitudinal reinforcement. They form a

basic design motif in the structure and rhythm of the façade and thus characterize the

overall appearance of the building. The external appearance of the hall is characteri-

zed by the lightness of the glass-aluminium shell. The use of white glass, the special

surface structure and the staggered installation method result in a changing sculptural

expression depending on the light.