This construction kit represents sustainability and enduring value — a timeless companion for cross-generational play and building.
It is a true work of art, crafted with love and dedication, inviting creative exploration through its aesthetic design.
Two sizes.
Infinite possibilities.
BK 4.0® – large and small.
This construction kit represents sustainability and enduring value — a timeless companion for cross-generational play and building.
It is a true work of art, crafted with love and dedication, inviting creative exploration through its aesthetic design.
Two sizes.
Infinite possibilities.
BK 4.0® – large and small.
BK 4.0® Large
BK 4.0 large natural: €1,905.00 (incl. VAT)
BK 4.0 large lacquered: €1,990.00 (incl. VAT)
BK 4.0® Small
BK 4.0 small natural: €1,339.00 (incl. VAT)
BK 4.0 small lacquered: €1,451.00 (incl. VAT)
- M
- C
- A1
- A2
- B1
- B2
- D1
- D2
- E1
- E2
- F1
- F2
Protected by European Community, Design No. 015079933
Download the brochure as a PDF file
Why we developed this construction kit
Good design and building do not have to be complicated. This construction kit was created to turn ideas into reality quickly, clearly, and with enjoyment. When people actively engage in the process themselves, learning becomes more sustainable and meaningful. Its clean design language, natural materials, and durable craftsmanship make it a unique play and learning object.
Our construction kit has significant educational value and combines thoughtful functionality with high design quality. It is more than just a toy – it is a long-lasting, educationally valuable design element for children and adults alike, promoting logical thinking, problem-solving skills, and fine motor development.
Creativity needs space and — the right materials.
Our construction kit is more than a product: it is a tool for discovering, experimenting, and thinking further. Instead of rigid instructions, it enables free, imaginative building while naturally fostering essential skills such as spatial awareness, concentration, and perseverance.
Made from solid FSC-certified beech wood
Free of preservatives and solvents, safe for chewing and licking, vegan, and weather-resistant
Handcrafted in Germany
Slide-in lid made of five-millimeter acrylic glass
Behind this project is Michael Schliemann
He developed the BK 4.0 many years ago out of a passion for wood and construction. Today it has evolved into a high-quality modular wooden construction kit — precisely crafted from solid beech wood (FSC certified), available natural or lacquered, and entirely produced in a German carpentry workshop.
The kit is intended to create sustainable, long-lasting toys that bring joy to both children and adults while also supporting regional craftsmanship.
You are welcome to place your order by email or through the order form: