The villa in Driebergen is a monument from the beginning of the last century. The owners bought this villa from the municipality because they had a very progressive idea of transforming this monument into a zero-energy house. Together with OPAI (Rau Amsterdam) there was a plan to realize the first energy-neutral monument of The Netherlands: a house that provides its own energy by high quality systems. Within the energy concept the house is isolated with natural materials such as reed mats and flax. The old wooden window frames are preserved and provided of insulating secondary glazing. Zecc architects integrated the energy concept in the existing monument and adjusted the villa to the wishes of its future residents. A new extension on the back strengthens the relationship with the garden and opens the house to the green surrounding.