How can the KB, National Library of the Netherlands, preserve its collection of over 120 kilometres of books, newspapers and magazines? Is there a more sustainable way to store the collection? The KB is researching the best way to move the entire collection from the current building to a new external repository. In collaboration with the Cultural Heritage Agency, Helicon conservation support and the Speicherbibliothek in Switzerland, and with means funded by Metamorfoze, we are working on finding the best answers for our preservation queries.

A sustainable, low-energy repository

The KB wants a sustainable, low-energy solution for the new repository. The building must be well-insulated, and damp and moisture-proof. This will create the optimal conditions for preserving the collection.

Passive climate control

In the current repository, temperature and humidity are regulated by an active climate control system. The new repository won’t contain such a water-bearing, climate control system, but a passive one. Meaning that the indoor temperature will fluctuate with the seasons and on average, it will be cooler. In such a system, the mass of the building and the collection will slow down the fluctuations in temperature. This is the case because the density of the building creates a balance between the natural moisture in the collection and the humidity of the air. In these circumstances, the humidity and temperature of the collection will have a direct impact on the new indoor climate.


Before we move the collection, we need to understand the specific construction physics of the building, and the impact that the collection itself will have on the indoor climate. We need to know exactly what needs to be taken into account when we switch from active climate control to no climate control in the repository. Does the collection need to be acclimatised before the move? What will the climate conditions in the new building be like when it is finished?

We will test this using a thermal-hygric simulation model of the new repository, which will allow us to mimic various scenarios. The model will be verified using actual data from a similar repository in the Speicherbibliothek in Büron, Switzerland, and measurements from our own collection. This will help us to understand the impact of certain constructional specifications on the stability of the indoor climate. Conversely, we will also use the model to gauge the impact of the collection on the indoor climate, both during and after the move.

The research started in 2021 and is set to run for 2 to 3 years. We will present the provisional results at professional symposia and in publications.

The Netherlands heading for circularity by 2050

The KB has chosen a sustainable, low-energy solution for its new repository. In this way, the KB is contributing towards one of the goals of the Paris Agreement - to make the Dutch economy completely circular by 2050.

The KB wants this research to serve as an example for other heritage institutions. How can you make a safe and careful switch to a more sustainable repository? The simulation model is open source and will be available to all.

Project group

The KB is working on this project with the Cultural Heritage Agency and Helicon conservation support. We are also in close contact with the Speicherbibliothek.

In addition, we share our knowledge with the team at Eindhoven University of Technology. They are running a Metamorfoze research project for the National Archive into indoor climates for archive collections. We keep each other informed about our progress in both projects, exchange knowledge and data, and check each other’s simulations where possible.


Foekje Boersma