Outside venetian blind concealed in cavity wall

Upgrade your façade with the outside venetian blind BZ1000 – a combination of refined design and advanced functionality.

Invisible box

Enjoy flawless aesthetics with a box that is completely invisible and is perfectly integrated into the cavity wall without perforating the building’s shell. These outside venetian blinds are a genuine asset for your home.

Installation in the cavity wall

Enjoy discrete installation, concealed in the exterior wall. Whether you choose guide rails in the cavity wall or cable guides with an elegant cover, the BZ1000 blends harmoniously with your home.

Dimensions up to 20 m²

This outside venetian blind is robust and wind-resistant. With dimensions up to 20 m2 and impressive wind-resistance of up to 80 km/h (EN 13659), the slats remain stable thanks to the innovative spring tensioning system.

Mix & match your colours

Our boxes and profiles are painted carefully in our environmentally-friendly paintshop. Choose from a huge range of over 300 RAL colours and diverse textured paints, all without a surcharge. Create your unique style with your own colour palette, without extra costs!

Outside venetian blinds, a durable choice

Discover the benefits of our outside venetian blind, a smart combination of functionality and design. The adjustable slats offer maximum heat blocking and light regulation in an efficient and functional manner, at any time of day. Enjoy the following benefits:

  1. Temperature regulation
  2. Energy efficiency
  3. Privacy
  4. Light regulation
  5. Protection against UV rays
  6. Aesthetic appeal
  7. Safety
  8. Low maintenance
  9. Customised


Why choose Harol?

100% guaranteed quality

Our Belgian craftsmanship, accurate to the millimetre, is supported by over 75 years of experience, allowing us to continuously maintain the very highest quality standards.

Design awards

Numerous international awards recognise our persistent product development and constant drive for innovation, aiming to provide greater durability, comfort and well-being.

Customised solutions

Harol supplies 100% made-to-measure solutions, where every detail counts. Our roller shutters, solar shading solutions and pergolas with endless personalisation options can be perfectly matched to your wishes.

Full service from start to finish

Choose a reliable and transparent partner who offers professional advice, specialised installation and a robust 5-year quality guarantee to ensure your satisfaction.

Why natural cooling

Our mission statement, “We Believe in Natural Cooling,” lies at the heart of all our efforts. We consider smart solar shading to be the most natural and energy-efficient way to block heat. Compare it to a tree providing shade: just as you seek natural cooling under the branches of a tree, sun protection keeps the sun out and your home, patio and workplace pleasantly cool. It offers natural air conditioning for your home which is healthy but also environmentally-friendly.


  • Savings on your energy bill
  • Passive cooling in the summer
  • Insulation in the winter
More about natural cooling