Forest Zevenhuizen, nature-inclusive living in and with wood 

In the ‘Swanladriehoek’ in Zevenhuizen, an area traditionally frequented by swans, five green neighbourhoods are being built: Forest, Meadow, Nest, Pool and Gaard. A total of 212 homes will be built in the Swan Triangle: 152 owner-occupied houses and 60 rental flats. There will be a mix of different housing types, such as flats, terraced houses, semi-detached houses and detached houses. A conscious choice was made for sustainable and circular building materials for these houses. Instead of stone walls, the construction of the row houses in the first construction phase (Forest) will be made of CLT (Cross Laminated Timber). In the Swanla Triangle, the homes are already being pre-sorted for the future and built in accordance with ENG (Energy Neutral Building) requirements. The Forest sub-plan comprises 32 sustainable and nature-inclusive homes and is now sold out. Construction of the ground-level homes in Woud will start in October 2024. 

The Woud homes are being developed by Synchroon. The property developer describes itself as a conceptually driven area developer that does not ignore monstrous problems, including climate issues. Noor Aghina, Synchroon's project developer, talks about the choices made and experiences so far.
 

How did Synchroon get involved in the project?
"In connection with the urbanisation challenge in and around Zevenhuizen and its consequences for the level of facilities, the Zuidplas municipality spent quite some time studying the development possibilities of two locations, namely the Van ’t Verlaat sports park and location the Swanladriehoek. This involves relocating the (growing) sports activities from the Van ‘t Verlaat sports park to the Swanladriehoek and using the vacant sports location for housing. Housing will also be developed at both locations (Van ‘t Verlaat and the Swanladriehoek). In close cooperation with the municipality, landscape architect ECHO Urban Design and civil engineering consultancy Waalpartners, an urban development plan was developed on behalf of Synchroon. Parallel to this, Synchroon acquired part of the land in the Swanladriehoek from Eagle Development B.V. After concluding a cooperation agreement with the municipality, Synchroon began work on the building development. The surface development of the homes is entirely for the account and risk of Synchroon. The municipality is responsible for the development and realisation of the sports facilities and for the realisation of the park and public area."

What starting points and choices were made?
"From the start of the development of the homes, we carried out research with the consultants and the architect into the CO2 emissions of the design and the materials to be used. For instance, not only was the impact of using a wooden main bearing structure considered, but also the use of bio-based insulation, the application of a green roof, etc. Here, the impact on CO2 emissions is also always mirrored by the impact on construction costs. For the wooden houses in the Swanla Triangle, the choice was made to build the main load-bearing structure in CLT and the internal cavity walls in HSB. Bio-based insulation is partly used. The houses have a green roof. The houses are equipped with a heat pump system based on ground heat. There are PV panels on the roofs with the premise that the houses are energy-neutral."

What are the experiences? What areas for improvement and what will go along to a follow-up project?
"For now, the building costs to convert the main load-bearing structure from, say, sand-lime brick to CLT are very substantial.

This requires the developer to invest heavily, as these additional costs cannot be factored into the VON prices of the houses for the time being. Buyers do not want to pay extra for a wooden house.
It is important to be aware of the emissions you realise at every stage of the design. That way it can be addressed at every stage. CO2 reduction was and is therefore a standard item on the design team's agenda. In this project, the contractor was also at the table from the start. Together with the contractor, we must also get subcontractors to visualise the emissions of their work. There is still some way to go there.
We have also worked on the project to dispel myths about timber construction, such as with regard to fire safety. But so far, buyers and potential buyers have asked few questions about this.