Strotec B.V.

Strotec is the organisation behind the EcoCocon prefab rapid construction system, which is in principle suitable for any building. It is 99% biobased and consists of 10% wood and 89% straw. It is vapour-open, but insulates optimally. Straw stores large amounts of CO2 during growth and is an agricultural residual product. Because it is harvested annually, it stores up to ten times as much CO2 per year as, for example, in wood. With this system, even CO2-negative construction can be done and other building materials are compensated.

Pleasant indoor climate with hardly any installations.

Made of

  • 89% straw
  • 10% wood
  • 1% reusable metal studs with which the elements are screwed together.

Production Process

  • Grain grows on the field (in the Netherlands enough for 75,000 houses per year).
  • Grain is harvested and threshed; the straw remains as a residual product.
  • In a production hall, wooden frames are made exactly to size on the basis of design.
  • In these HSB crates, the now dried straw is pressed (maximum 15% humidity).
  • Then the building elements are numbered and delivered to the construction site at the last minute.
  • After possible decomposition, the material can be reused and returned to nature.


The building elements are used as vapour-permeable, constructive interior-exterior facades for homes (Eindhoven, Oostmahorn, Kaatsheuvel), Sports Hall (Tegelen), schools (Almere, Amsterdam), offices (Helmond) and in combination with CLT can also be used for stacked build.

Environmental impact

  • The material is 99% biobased.
  • It makes CO2-neutral construction (or even CO2-negative) possible.
  • EcoCocon stores approximately twelve tons of CO2 per home.
  • Grain is harvested annually, which means that up to ten times as much CO2 is stored as, for example, in wood.
  • After possible degradation (fifty to one hundred years), the material can be reused per element and – ultimately for 99% – back into nature.

Good to know

  • Ecococon provides a wonderful indoor climate; even temperature and humidity.
  • Good acoustics, especially in combination with loam.
  • Fire certificate of 120 minutes.
  • Super insulation (Rc 8.3), which means that hardly any installation is required for heating and cooling.
  • Form-free construction concept (any design fits in).

growth opportunities

Because construction is a major CO2 emitting sector, the standard for CO2 emissions will be further tightened. Strotec offers a serious alternative for this with its fully biobased and cradle-to-cradle construction system. Because the raw materials are widely available, the growth opportunities are almost endless. But the problem lies in the extent to which people in the Netherlands are used to building with brick.

The fast building elements have so far only been produced in Lithuania, but a production line will be built in the Netherlands when there is sufficient sales here.