In the Dutch town of Sneek, an old warehouse was repurposed to serve as much-needed base for assisted living apartments. The Rockzero® Building system from ROCKWOOL ensured that the transformation took place in record time – while securing the highest insulation values.

Dutch real estate developer, RTR Vastgoed, owned an existing warehouse built in the 1950s. Located in a prime residential area right in the centre of Sneek, the potential of the building was huge – particularly if it could be extended vertically.

The challenge

The aim was convert the warehouse into eight split-level apartments, with some being built on top of the existing structure. The apartments would be leased to the local care institution, the JP van den Bent foundation. As the
development would take place in a residential area, they needed to be constructed as quickly as possible to minimise disturbance to those living in the area. But the greatest challenge was the fact that some of the apartments would be created above the existing warehouse – more literally put, built on the roof! So the apartments needed to be lightweight yet stable.

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Sneek, The Netherlands

Project location

Warehouse conversation
The Netherlands

"The Rockzero Building Systems worked out well, because the system is very flexible and very suitable for making adjustments quickly in the work process. This system contributes extremely well to a smooth construction process.”

Bernd Bove

project manager at Adema Architects

Collaborating for success

A floating cement floor was placed on the wooden floor to acoustically insulate the homes. Using the Rockzero building system, based on ROCKWOOL’s stone wool, the apartments achieved exceptionally high insulation values – almost at passive level with an RC value of 6 for the façade and an RC value of 7 for the roof. The building system ensured an optimally insulated and fireproof construction, with no cold bridges. The building plan included the installation of approximately 240 solar panels on the flat roof, to supply tap water, warmed by nature, in each of the homes.

It wasn’t the first time that RTR Vastgoed collaborated with Adema Architects. Bernd Bove, project manager at Adema Architects, particularly enjoyed working on this transformation challenge, and explained that the
entire area – formerly very industrial – has undergone thorough change to become a residential zone.

“The building initially had an industrial look that has been completely transformed to become charming homes,” sat Bove. “This pilot from RTR Vastgoed was the last to be rebuilt in this area. In this eight-meterhigh building, split-level homes have been built to create a spacious living quarter that is accessed through a cosy communal courtyard. The floor and part of the façades of the old shed have remained intact, in which the steel construction has been adapted to accommodate a wooden floor and the Rockzero building system.”

Stephen Muller, key account manager at ROCKWOOL, regularly visited the project throughout the construction period.

“For us, this transformation was extremely interesting, because it was the first time we’d used the Rockzerobuilding system within an existing building. RTR Vastgoed chose our building system to be able to apply a lightweight, fireproof façade with façade cladding, which could be built quickly and flexibly on and against an existing building,” explained Muller.

The Rockzero building system contains columns of stone wool, which have a strong structural loadbearing capacity. The building system is light, flexible, non-flammable and insulates well, due to the fact that it is based on ROCKWOOL’s stone wool.

“As a result, the system is suitable for any type of façade and façade finish,” continues Muller. “In this project, the building contains different types of façade finishes that demonstrate that flexibility, such as existing and new masonry and façade cladding. The system is modular, arrives to the site and can be assembled directly.”

The success of the project at Sneek was the direct result of positive team work from RTR Vastgoed, Adema Architects and ROCKWOOL’s technical solutions centre. By using the Rockzero building system, they could rapidly development safe and comfortable homes for
local people with special needs.

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Rockzero – making sustainable housing accessible

If it’s necessary to construct a new building, it makes sense to use the latest in available technology to ensure that it’s as energy efficient and sustainable as possible. Nearly zero-energy buildings (NZEB) have very high energy performance – and the small amount of energy that these buildings require comes mostly from renewable sources. According to the EU’s Energy Performance of Buildings Directive, all new buildings must be nearly zero-energy by the end of 2020.

ROCKWOOL developed Rockzero to meet this need. With Rockzero, you can build homes with superior energy efficiency, fire protection, indoor comfort and sound insulation, that deliver on energy performance as calculated and that are airtight yet breathable. Rockzero homes are lightweight and modular, allowing new homes to be constructed quickly, meeting standards that exceed local regulations and giving long-lasting durability. This makes it easier to construct next-generation sustainable homes – while using less valuable resources. Thanks to the Rockzero Revit Plug in, customers can also receive support in the digital space using BIM (Building Information Modelling).

The performance of Rockzero exceeds current and future energy regulations without the use of other energy sources and with no restrictions on the orientation of the building or choice of primary heating source. Rockzero has no thermal bridges, so it performs consistently, regardless of the building’s layout. As stone wool insulation is robust and durable, you benefit from predictable low energy and maintenance costs for decades. With Rockzero, you’re ready to meet the requirements of tomorrow.

Project Data

Year 2019
Building Type Multi-unit housing
Application Rockzero – walls and roof
Product type

Rockzero Bouwsystemen