Hello Mr Räuber, let's start with the grand total! At the end of 2022, the DNB boasted an impressive inventory of more than 46 million media works occupying more than 400 kilometres of shelving. You can sort out and dispose of the books you have at home, but nothing ever gets thrown away at the DNB. That's why the fifth extension is soon to be built in Leipzig. What can you tell us about how this is progressing?

The planning rationale has been accepted and the construction planning has now begun. We've worked out that we'll need around 17,000 square metres of space to accommodate the increasing volume of media. The questions now are: what can we realise in this space? And what will the extension actually look like? The next step will be an architectural competition in which architects will be invited to create a design for the new building. Once we have the results of the architectural competition, we'll know what the new structure will eventually look like.

And the DNB won't be providing any style criteria?

It goes without saying that we want the extension to blend in with the cityscape – we can't just put a high-rise building there because this would basically destroy the entire skyline. That's why the city and the urban planning authorities also have a say in the matter; after all, the new building will be constructed in a relatively prominent location. Ultimately though, our ongoing concern is to have as much capacity as possible. What we always want to know is: how much will we be able to get inside?

When will the fifth extension be ready for occupation? 

If all our plans work out, everything will be good to go in 2028/2029.

And how long will the capacities of the new building last?

What we're doing is rather like looking into a crystal ball. All we did was to project the three kilometres of new shelving we need in Leipzig every year into the future, because contrary to all the naysayers, we are not seeing a decrease in the volume of paper being printed. Although it's only ten years since the fourth extension was built, we find that we're already talking about the fifth. This is why we've decided to break up the planning grid and plan capacities for the next 30 years.

Now let's talk about the DNB in Frankfurt am Main. The capacities there won't last for ever, either. What can you tell us about them?

The premises in Frankfurt are much more spacious. At 26 years of age, the building is relatively new. What's more, the planning at that time was very farsighted and incorporated capacities for 50 years. In Frankfurt, we also have very generously proportioned stacks with wide corridors for electric conveyors that we no longer use. This means we can condense the existing collection to free up even more space. As matters stand today, we won't need an extension in Frankfurt until the end of the 2040s, if then.

And what about the plot of land in Frankfurt, which according to the city's urban development plan is designated for "special library use"?

Our predecessors secured this plot of land with admirable prescience. We are of course keeping it in mind for the expansion of our storage space – and we won't be giving it up. But because we won't need it until later, we now want to put it to temporary use. After all, it would be a shame just to let the land lie fallow. That's why we're getting together with the universities in Frankfurt and erecting a digital study centre on the site. We're currently developing a utilisation concept, which is why I can't be more specific as yet.

Now let us zoom in a little and take a look at the construction work going on in the existing buildings. One of the things you've done is to install a BOS radio communication system. What is this exactly?

Put in simple terms, it's the radio network for authorities and organisations that perform tasks in the interests of public safety. We've installed an extensive network of antennas and amplifiers on site so that firefighters, police and emergency rescue teams can communicate deep down in the stacks. If you walk around our stacks with your mobile phone, you'll find that the reception is poor to non-existent. Obviously that's a problem for firefighters, because they communicate by radio. Understandably, they won't go to places where they can't communicate so as not to put themselves in danger. That's why we have to make sure that they can communicate in every corner of the house – and this is what the safety radio system can now guarantee.

Now let's talk about user friendliness. The visitor cloakroom in Leipzig, for example, is now complete. How did this happen?

Yes, the cloakroom where visitors handed over their clothing and bags was getting very shabby indeed. The lockers had no locks, or they weren't working properly. It wasn't a pretty sight, nor was it user-friendly. That's why we've now built a new cloakroom with a self-operated electronic locking system.

And how does it work exactly?

In principle, there are three ways to operate it: visitors can use their DNB library card, a pin they create themselves – which is useful for people attending events – or the app. In a way, the app itself was the "spark" that triggered other ideas which can be realised using it. The app could be used to publish information about the DNB, for example, to provide a kind of navigation system for the libraries or to display the cafeteria menus – all these concepts are being developed, and the whole process is quite complex. I also assume that we'll be offering online versions of our library cards at some point, which people can display on their smartphones.

So there are plenty of digital and analogue construction plans! Which others will our readers find interesting?

We are planning to convert the conventional media loans set-up in both libraries. Our aim is to change the current system with the counter where our staff issue the media. The idea is that staff will be able to place the books ordered in a locker which the user can open with their library card. This will mean that basic functions – the issue of books – can be performed irrespective of time constraints. It also means we will be able to allow visitors to come at times that are currently very inconvenient for our staff. And our staff will only have to work during the hours of service when they are really needed.

When will the whole thing be realised?

The first prototypes will be introduced in our buildings in the autumn of 2023. For this, we will have to do quite a lot of conversion work in the user areas. We will also be taking the opportunity to convert the info counters that are currently scattered throughout the building. Our users are in much greater need of a central reference point, a central service counter. This will be where they can ask all their questions and get directed to specialist staff if need be. We also plan to set up rooms for individual and group work, depending on the conditions in each building.

And what is the time frame for this plan?

Work in Leipzig will start in the autumn of 2023, and it's sure to continue until the late summer of 2024. This is also because we have to renovate the whole reading room – so we'll be doing everything in one go. In Frankfurt, the work will start no later than the summer of 2024 and continue into the winter of 2025. Afterwards, we will justifiably be able to say that we have an attractive, functional user environment in both buildings!