Restoration of Trompenburgh

April 9, 2024

Monument Property is working hard on the restoration of Buitenplaats Trompenburgh. We are pleased to share two new updates on the restoration of this unique monument. Special finds were made during work in the dome vault.

We have roughly broken down the restoration of Trompenburgh into four parts: restoration of the building, preservation of the building, renovation of the garden and opening to the public. In this item, we share updates from two of the components via short videos. In the first video, project manager Robin Koot shares our approach to making the building more sustainable. This was an important but complex task for this landmark building. In the second, newest video, conservator Annefloor Schlotter talks about the discoveries she and the restoration team made while restoring the domed hall. Earlier, the team had also made extraordinary discoveries.

Building sustainability

Monument Property has worked intensively to make the building more sustainable. We applied both low-tech and high-tech sustainability measures. By low-tech, one thinks of, for example, applying crack sealing, insulation of floors and installing water-saving faucets. These measures were implemented last year. In addition, large-scale, high-tech solutions have been applied. For example, the domed hall is now heated via underfloor heating, powered by a heat pump installed last year.

Making a monument more durable is also about choosing materials that will last longer. That's why a different approach was taken when replacing the lead covering on the roof. The new lead roofing was installed in a ventilated manner, allowing the lead to last much longer.

Once all the measures are implemented, Trompenburgh will go from energy label G to label F. Although this seems like a small step, it means an improvement in the energy index by as much as 27% and a 45% reduction in CO2!

Restoration of the dome vault

A team of 20 conservators, led by Ruth Jongsma of the Bureau of Color Research & Restoration, is currently working to restore the dome vault. In recent months, they have made a remarkable discovery

The original 2019 plan for restoration of the dome vault included removing the old, yellowed layers of varnish, consolidating, filling and retouching the paintings, as well as applying a new coat of varnish. In 2020, preliminary research revealed that an intact 17th-century painting may be hidden beneath the brown layer.

"Therefore, in the current restoration, we started by creating a test surface in one of the vault segments. We removed all the overpainting. Then original, subtle details became visible again and the painted architecture suddenly gained more depth. As a result, the domed hall came back to life," says conservator Annefloor Schlotter. In this video, she further explains the approach and discoveries.


In 2020, we started the restoration of Buitenplaats Trompenburgh. We plan to begin work around the garden in the second half of 2024. The garden structure around the house will be restored. Since the house was originally more surrounded by water than it is now, a section will be excavated and refilled with water. In addition, a wooden access bridge will be installed, as it looked in the 17th century.

The exterior work is expected to be completed in 2025. Then the restoration of the interior should also be largely complete, and the buitenplaats will become accessible to the public. From then on, the building will be given a cultural-social purpose and made available for rentals, events and receptions.





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