Construction of the 67-acre facility began in June 2020. The first trains to be assembled there will be the new Piccadilly line trains for Transport for London. The facility, which sits between the M62 motorway and the River Ouse, is dominated by three large separate buildings for the assembly, single car testing and commissioning of the trains, with each building requiring a heating and ventilation solution. 

An initial feasibility study in March 2022 examined various options, including the installation of a mixture of RoofVent and TopVent units. Following an update from the contractor in June 2022, which included detailed layouts of the three buildings and heat loss calculations, further discussions took place, establishing heat loads and the buildings’ desired outside design and indoor temperatures.

Siemens Mobility's desire for a gas-free site led to Hoval recommending its TopVent TP, a decentralised recirculation unit designed to heat and cool high spaces. Equipped with an air/air heat pump system (which generates both heated and chilled air for year-round operation), the units utilise energy in the ambient air for environmentally-friendly heating and cooling. The heat pump can be located up to 50m from the TopVent unit, whose temperatures are controlled by the TopTronic C system.