Montlegia hospital – Liège

July 5, 2016


Client:  Christian Hospital Centre of Liège (CHC)
Period:  2010-2012
Size:  113.000 m²
Team:  Assar Architects – Artau – Hoet + Minne, Greisch, Tractebel Engineering, 3E


The new Montlegia hostpital (Christian Hospital of Liège -CHC) will have a capacity of about 750 beds. It consists of two main entities: the “patient’s accommodation“ building and the “medical-technical” building.

The building’s energy & comfort design is realised using thermal dynamic simulation software. It allows to model a three-dimensional construction, and to segment the building in different thermal zones to which different performance scenarios (hypotheses) were applied.

The methodology consists in comparing the different energy concepts analysed in each phase of the project, to propose and combine different improvements in order to select the energy concepts that best meet the energy efficiency and thermal comfort targets defined by the client.

Based on 3E’s study work and analysis, the client chose the final design that includes the following characteristics:

  • The heating and cooling needs of the building remain below 15kWh/m².year, excluding process equipment.
  • The adoption of Atria combined with a natural ventilation strategy has proven its effectiveness on maintaining acceptable summer thermal comfort.
  • The implementation of efficient artificial lighting enables to minimize the electrical power consumption and to reduce the overheating in sensitive areas during the summer period.
  • Rooms with variable occupation profiles (meeting rooms, etc.) will be equipped with special lighting control and ventilation rates based on the actual occupation.
  • In the “medical-technical” area, increasing insulation levels of inner walls adjacent to different temperature zones minimises the transfer of heat and cold from one area to another.

Some building specifications:

  • Overall thermal insulation level < K29
  • Heating needs: < 15 kWh/m².year
  • Cooling needs: < 15 kWh/m².year
  • Insulation envelope: Average U = 0.3 W/m²K (10cm of graphite EPS on the facade)
  • Windows (frame + glass panes): Uw = 1,3W/m²K
    glass solar factor (g) = 0,26
  • Air sealing: 1 vol/h