Case Study: VMM Passive Building

3E designed the energy concept of the Flemish Environment Agency's (VMM) new office and crisis center for its water management department.

In order to optimize energy use further and be a real example of energy performance, the VMM has had a full monitoring system installed and has asked 3E to continuously oversee and help optimise energy performance over the years.

Now well into the second year of data collection, the analysis and full data are being published here as reference material and input for researchers, academics and public stakeholders. The initiative is meant as a basis for exchange and development of experiences with passive buildings.

More on the building

The VMM building is situated in the outskirts of the Belgian town of Leuven. It is primarily a home for the servers hosting the new forecasting and protection system of the basins of the Dyle and Senne rivers.

The building is designed for highly variable occupancy profiles. Meant to be used by about 5 people during normal office hours, it can house up to 40 extra people on a continuous basis during crises or exceptional circumstances. The building is currently being used regularly by 15 people.

The building is a very comfortable passive one, built with sustainable materials and including water management facilities.

Energy performance

Heat consumption (planned): 14 kWh/m².year
Envelope insulation: U_avg = 0.20 W/m²K (28 cm of mineral wool on façade)
Triple glazing U_w =0.60 W/m²K  -  solar factor g = 32%
Airproofness (in situ test results): 0.5 vol/h (not counting garage)

Key systems:

• D ventilation system with heat recovery η=85%
• cooling of server room through thermal transfer from ground water
• heat recovery from server room via heat pump
• PV system (4.2 kWp)