Delft City Hall and Train Station is proposed as a transparent glass form, a pattern of diagonals within the façade transforming the classic sheet into a shattered diamond-style exterior. Currently, Delft's city centre is intersected by an obtrusive railway viaduct; however the construction of an underground railway tunnel hopes to remove this barrier from the dividing city.
The first floor of the proposed building will hold multifunctional spaces, a restaurant, conference rooms and rooms for the Mayor and Alderman, whilst the ground floor is split into two separate volumes by a dividing glass wall. Within both areas will be public counters, a front office, interview rooms, stairways and elevators to the upper offices, commercial facilities and sanitary facilities. By enclosing the ground level in glass, Mecanoo attempt to combine the activity within the interior with the buzz of everyday life outside the facility.
Many features of the Delft City Hall and Train Station have been adapted for sustainable benefit and this has not gone unnoticed by the jury of the Green GOOD DESIGN Award 2010. With energy use 35% less than governmental recommendations and an estimated GreenCalc+ score of 300, the design features solar panelling on its rooftop to provide 20% of the building mechanics and light electricity load. Thermal storage will be used to regulate climate control, depending on the orientation of the sun and building with waste heat then reused through a heat wheel.