21 December 2022

Trees in the city: it seems to be a natural phenomenon. Dig a hole, plant a tree and wait for it to grow. Right?

Unfortunately, it usually doesn’t work this way in practice, especially in the urban environment. The life expectancy of the average urban tree is only ten years.

At TreeBuilders we apply tree bunker systems in the urban environment to significantly extend the life expectancy of trees. Only then can we benefit from the important environmental benefits that healthy trees have to offer us. Benefits such as cooling the air and keeping it clean, increasing biodiversity and reducing peak discharge during heavy precipitation.

Putting plastic in the ground?

TreeBuilders’ tree bunker system, called TreeParker®, consists of plastic made from recycled materials. We notice that this often raises questions in practice, such as ‘isn’t plastic bad for nature?’ or ‘why would you put plastic in the ground?’. We fully understand this question. That is why we are happy to explain the story of the TreeParker® system to you.


It all starts with diapers. Yes, you read that right: diapers. For babies.

The production of diapers leaves a lot of residual waste. However, ‘waste’ is not the correct term for residual waste. We prefer to call it ‘raw material’.

This is what happens step by step with the diapers:

  1. The diapers are ground into small granules, called plastic granulate.
  2. The granulate is melted together into one substance.
  3. Using advanced injection molding machines, the substance is processed in custom-made moulds.
  4. The molds form the substance of modules for the TreeParker® system, such as decks, frames and posts.
  5. And voilà: the diapers have become a flexible and modular system!

At the end of the production process, the TreeParker® units are tested for strength at the factory. This is important because the system is used underground. The units must be able to withstand the heaviest traffic loads. The power of the system is therefore also an important point that has been included in the design process.

TreeParker® is a very strong system that has proven itself to be able to support the heaviest traffic loads while maintaining the integrity of the road surface. In this way, safety in the public space can be guaranteed.

Rootable space for urban trees

After the units have been produced and tested, they find their way to green and infrastructure projects in the urban environment. The units are installed underground and create space for tree roots to grow unhindered under the road surface. This way the trees can grow into mature, functional trees between concrete, pavement and buildings.

TreeParker system TreeBuilders

Liveable and vital cities

Thanks to recycled diapers, which are converted into our plastic TreeParker® system, trees have the chance to grow old healthily in the urban environment.

So, is plastic really that bad for nature? We don’t think so. If you don’t waste plastic, but just recycle it and use it for the right purposes, plastic is a valuable and sustainable addition to our environment. By planting trees in cities, we create a future-proof, climate-adaptive and healthy living environment.

More information

Do you want to know more about the TreeParker® system? Go to https://www.treebuilders.eu/products/structurail-soil-cells/ and find out all about our tree bunker system.