Kantoor Deltawind

Designed by RO&AD architects, Kantoor Deltawind will be the new office, heart and collaboration hub for the Coöperatie Deltawind. With its timber structure, bio-based insulation, reclaimed facade cladding, and smart HVAC system, it aligns with the cooperative’s sustainable ambitions and investments in renewable energy. Summum Engineering is responsible for the structural design and engineering for the final and detailed design.

As one of the largest local energy cooperatives in the Netherlands the Coöperatie Deltawind is co-owned by some 2,400 residents of  Goeree-Overflakkee. Its primary goal is the generation and responsible use of sustainable energy in and around Goeree-Overflakkee. Deltawind plans to build a sustainable and circular office at the BedrijvenPark Oostflakkee near the entrance to Oude-Tonge, as it needs more space for offices, meetings, and collaboration.

With the Kantoor (lit. Office) in Oude Tonge, they’re creating a new central meeting place for their members – the design representing their open and democratic philosophy as well as their mission to invest in and expand renewable energy. Sustainability as a main objective of the project had a strong influence on the shape, the choice of material, the design of the surrounding landscape and the installed building technology.

With the office building, the cooperative expects to inspire its development towards a sustainable society. By making choices that sometimes deviate from the usual, a sustainable, innovative and largely circular office building will be realised.


The Kantoor is long and tubular, resting on timber columns. Recycled wood is used wherever possible. Offsets in the facade and the extruding entrance characterize the north-eastern side of the building, while a greenhouse covers the whole south-western facade. Inside, a two-story high auditorium in one wing transitions via open and flexible work spaces into defined office and meeting rooms in the other wing. Openings on the mezzanine keep both levels connected and create communicative nooks in between.

The indoor climate is regulated naturally as much as possible, limiting the amount of installations. The greenhouse facade is part of this. Naturally, the building will be completely natural gas-free and equipped with solar panels and a battery. A garden will surround the building, contributing to the need for water storage and biodiversity. As much as possible, construction will be done with electric equipment to reduce nitrogen emissions.


Timber as a renewable material with a low carbon footprint is chosen for the majority of the structure. The facade is fabricated using timber-framed Multiplan panels, insulated with bio-based wood fiber and clad with reclaimed hardwood.

The facade-long greenhouse is not only part of the heating system, but houses deciduous plants, which offer shade in summer while welcoming the sun in winter. In combination with a narrow band of windows and a shed roof, they ensure natural light while the need for artificial cooling in summer is reduced. Photovoltaic elements on the southern side of the shed roof, maximize the potential for solar energy further contributing to the building’s energy mix.

Mounds and valleys are formed around the Kantoor, designed to self-clean the water through a constructed wetland, create new habitats, and encourage local biodiversity.


The main structure comprises a series of hinged frames in glued laminated timber with floors in cross laminated timber (CLT). Intersecting volumes with CLT walls form the central entrance building. Only the foundation and two installation rooms underneath the building are constructed in concrete. The greenhouse is designed as a steel-glass facade added along the timber structure.

A structural challenge was the lateral bracing of the frames, as they form big and uninterrupted spaces, leaving little room to build triangles without blocking the user’s space. After initial studies with parametric tools and in close collaboration with the architects from RO&AD, it was decided to welcome the bracing into the center of the design and let it define the spatial experience within the building.

With prominent diagonals, crossing both levels and ending in the middle of the floor, the frames achieve the necessary lateral stiffness while adding a distinctive dynamic to the elongated spaces.

Social function

The office building will be a place to meet and work together, to inspire each other and to share information. The building will have flexible workspaces, meeting places and a presentation room, which can also be used by people outside the organisation. Associations and other social initiatives are invited to use the premises as well. Residents of Goeree-Overflakkee with sustainable ideas can join to discuss collaboration. People who want to work on making their own homes more sustainable can visit the Energieloket (Energy Desk), which will have its own place in the building.


The cooperative’s new home will be a special addition to the entrance to Oude-Tonge. Deltawind and its members expect the investment to create added value for the cooperative and the surrounding area on all fronts. Deltawind intends to build a sustainable future together, starting with meeting one another at Kantoor Deltawind.


Coöperatie Deltawind

RO&AD Architecten
Vis-a-Vis (landscape architects)

Structural engineering
Lena Woidt, Rik Rozendaal, Diederik Veenendaal, Aitor Vadillo Barcelona, Tatsuki Fujiu | Summum Engineering
DaeD Ingenieurs (geotechnical consultant)

Bergh Bouw Systemen (main)
Lomans (installations)
Arcon Houtconstructies (timber)

Dubourgraaf (installations)

Location: Oude Tonge, Netherlands
Time: 2022 (design and engineering), 2023 (construction)
Status: TO
Size: 48.0 x 13.4 x 12.9m
Services: Structural design and engineering

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