Office GasTerra

Groningen, NL

Can sustainability and aesthetics go hand in hand?



An existing office building from 1986 guzzled energy and had an architecturally impoverished appearance. The Triodos Vastgoedfonds asked De Zwarte Hond to transform it from energy label G to A+.

The building went from energy label G to A+, was fitted with a quality plinth (1), an iconic accent (2), a good spatial connection (3) and a spacious entrance (4).

What were the main measures?

Super insulated glass with sun protection coating and thermal glass for the voids

Heat/cold storage with gas heat pump

Ventilation and pre-cooling from heat/cold storage, heat recovery

PV cells on the south-facing rooftops

Very low general lighting level, additional workplace lighting, presence detection, daylight control

Research into the effect of voids on the displacement of the floors, for the purpose of limiting construction material.

Using a ‘sustainability matrix’, all possible options for energy optimisation were identified and considered. Upgrading the insulation value of the outer wall would mean complete demolition and replacement of the existing masonry with insulation. That was not the most sustainable solution at a material level. However, a comparable performance could also be achieved by installing new window frames and including triple glazing, solar panels and a heat/cold storage system, linked to a highly efficient gas heat pump.

By always considering the architectural qualities in the choice of interventions, an attractive, spacious and open office building has been created where work can be done in a new way.

Office GasTerra

The Triodos Vastgoedfonds bought an existing office building near Groningen’s central station for a completely sustainable renovation. The building, from 1986, had a very negative energy consumption, no strong architectural appearance and poor architectural detailing. Triodos, together with the new user of the building, GasTerra, laid down a number of ambitious objectives in a ‘green lease contract’. The challenge was to transform the building from energy label G to A + in a smart, adequate way.

All the options for energy adaptation were carefully calculated and weighed, after which choices were made together with the stakeholder. In addition to their energy significance, all the interventions also had an aesthetic motif. The corner building gained a clearer image through reducing the multitude of details and solutions. In the heart of the building, the new void with stairs creates a central meeting place, provides beautiful sight lines and allows daylight to penetrate deep into the building. By reducing the amount of technology in the building, a place was created on the roof for a handsome new space with a panoramic city view.


Office GasTerra
Groningen, NL
7.130 m²
Harry Cock, Gerard van Beek
  • Nomination FGH Vastgoedprijs
  • Gouden Kikker Duurzaamheidsprijs
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