Sustainable renovation, respecting rich history

Renovating and preserving national and international monumental buildings requires careful technical preparation and execution. But it also requires working with respect for the historical value of the building and its surroundings and a sophisticated interplay between client and construction team partners. It is building and renovating at the highest level. Breman Utiliteit, a division of Breman Installation Group, understands this art. Various striking projects such as ANNO and the Statenzaal in Zwolle bear witness to this.

In the backyard of Breman Utiliteit's Zwolle branch, under city tower De Peperbus, ANNO was completed last April. In the building, a city museum, archaeology, building history, monuments and an archive had to be harmoniously brought together in approximately eighteen months. And that was by no means a sinecure, says project manager Jurjan Veenstra. "The project consists of three building sections, including the monumental 16^e-century Drostenhuis, a monumental Voorstraat and a new-build section from 1997. Commissioned by the municipality of Zwolle and in a construction team with contractor Hanzebouw, we upgraded the preliminary design for the mechanical, sanitary and electrical installations to an execution design, respecting the monumental value of the building parts. This was also strictly enforced. For example, the beautiful ceilings and many fireplaces made specific demands on the incorporation of the piping. Moreover, no drilling was allowed in walls and ceilings."

All installations out of sight

A solution for the ductwork was found in the old chimney flues. "Each room had its own chimney flue, into which we fitted our air ducts," Veenstra said. "All the ducts were routed through the old chimney sweeps and connected to the new ductwork in the attic, where we had a little more installation options. This way we were still able to provide all rooms with enough fresh air." In terms of heating, the desire was to take the building completely off gas, but this proved to be structurally impossible. "A number of walls in the Drostenhuis were not allowed to be additionally insulated," Veenstra explains. "As a result, we had too much transmission loss. We therefore proposed a hybrid solution with air/water heat pumps for each building, with a central heating boiler assisting on the coldest winter days. Because radiators would take up too much space, fan coil units neatly concealed in benches were chosen as the delivery system. The piping is concealed behind the monumental paneling." Because of the inner-city location, ANNO's heat pumps are set up behind a beautiful coir sound wall, so you can't see or hear the installation.

Besides the walls and ceilings, Breman Utiliteit Zwolle was also not allowed to drill through the monumental floors. Therefore, in many places the monumental floorboards were partially removed and - after installing the electrical installations - carefully restored. "All cabling for CCTV, lighting, data and electricity has been fitted invisibly into the floors, so that an authentic appearance and the most modern technology come together harmoniously."

New use for former State Hall

A second unique and local reference is project Statenzaal. After Zwolle was renamed the capital of the province of Overijssel in 1803, buildings such as a provincial house and government building were needed. In 1895, construction began for the corresponding Statenzaal, which is characterized by a neo-Gothic style. This is reflected, among other things, in the beautiful stained-glass windows, which depict the arms of Overijssel municipalities. Monumental murals also depict highlights of the province's history. The exterior of the building was already renovated in 2009. Until 2016, the building was used as a library, but now it is time for a different use. Therefore, the historic building is now being converted into an event hall, hotel, grand café and hostel. All work should be completed in early 2023.

Careful alignment

Commissioned by and in a construction team with construction contractor Prins Bouw, Breman Utiliteit Zwolle is providing all installation engineering work. "Based on ABT's specifications, we provided the engineering of the mechanical, sanitary, electrical and control installations," says project manager Wim Holstege. "At the beginning of this year, we started execution. All our work is carefully coordinated with the municipality of Zwolle and the Rijksdienst voor Cultureel Erfgoed (RCE). In this way, we achieve high-quality solutions throughout the building, without affecting the authentic historical quality."

For example, the monumental tile and paint work must not be affected. "To then still find the right pipe routes requires a lot of creativity from all parties involved. In the Statenzaal itself, for example, the number of lighting points has been reduced. The resulting gaps were cleverly used for the supply and return grilles of the air treatment system. As a result, we did not have to drill new recesses; an action that was strictly forbidden. In the hotel rooms, prefabricated sanitary units avoid having to drill into walls and floors." The facade components for the fire alarm system were moved to the side facade in consultation with the fire department and RCE, Holstege said. "This does not affect the historic appearance while maintaining visibility and safety. Air/water heat pumps, PV panels and air heating systems with top cooling also ensure optimum sustainability."