Hello Wood to build a school without concrete in Nagymaros

The building description for Bánáti + Hartvig Építész Iroda building description is available at Építészfórum published the Hello Wood; from which we can learn about the applicability of the CLT system in public buildings and the design criteria for a community-strengthening building. As the architects write:

"The client of the project approached our office following a previous school extension, the container building of the German School in Budapest, and envisioned a similar school building as the next educational site for Budapest School. The aim was a building that could be constructed with minimal environmental impact and that would also ensure that the pedagogical work carried out in it would be integrally linked to this ethos.

The creation of a container building was not allowed by the local regulatory environment, as there is no possibility of installing a flat-roofed or metal-clad house in Nagymaros.

Boundedness became an option, however, thanks to which we formulated a concept that meets the requirements of the townscape and environmental consciousness: the house should be built of CLT, i.e. cross-laminated solid wood.

Wood instead of metal

One cubic metre of wood sequesters nearly one tonne of CO₂ during its lifetime, which remains in the building even when installed as a panel. The production of panels requires much less energy than steel or concrete, and the production itself has a relatively low CO₂ footprint. If necessary, the elements can be dismantled, recycled or even used as biomass. If the material is sourced from appropriate forestry, it can even be CO₂ negative.

Because it is a prefabricated structure, there is minimal construction waste, which can also be recycled, especially if the designers are creative.

CLT is also an advantageous material from a fire safety point of view, as it can be accurately modelled. However, special attention had to be paid to the design of wet spaces, as the wood is sensitive to moisture. Similar attention was needed to create appropriate acoustic boundaries.

In a previous project, we had a motto: "don't paint, don't cover just to make it pretty". This approach has been applied to the school building for Budapest School, as CLT can be designed as a visible structure.

Completely concrete-free

Due to the properties of the CLT structure, a low environmental impact solution was also found in the design of the foundation: the building is supported by ground bolts - nearly 300 of them hold the girder grid on which the house will be built.

We rightly asked ourselves, if we had achieved the goal of avoiding cementitious building materials in the main structural elements of the building, why not aim for this in the overall design? We have therefore consistently sought to use cement-free, recycled or recyclable materials in both the interior and the landscaping: for the supporting beams we use a steel basket solution, while for the interior we use only ceramic tiles and their adhesives. A large part of the cladding is made of PVC, while polycarbonate is used for some facades. Most tiles contain a significant amount of recycled materials, but can themselves be recycled or reused.

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The design programme was for a school building with five classrooms and sixty pupils, with the possibility of expansion in the future. The building's layout was designed accordingly: a circular transport system organised around an internal playground formed the basis of the building, on which classrooms and additional functional units were added, including specialised rooms such as yoga and art classrooms.

The building has a high roof design, with a welcoming exterior from the Upper Field Street of Nagymaros. The entrance reflects the direction of arrival with its "indented" and colourful design.

The heart of the institution is the school car that connects the classrooms, a bustling communal space, but its small corners are also suitable for individual retreats. Children can access the classrooms directly from this space, which has large windows and a terrace facing the Danube, extending the educational function to the courtyard."