ÖSWAG

Background and challenges

In 2024, the ÖSWAG Maschinenbau GmbH contacted VELUX Commercial with a pressing issue: their 10 continuous rooflights were leaking, had no thermal insulation left, and even let rain into the building – seriously affecting factory operations. 

The old skylights had yellowed over time, allowing minimal daylight into the halls. At the time of installation, there was no requirement for smoke and heat ventilation (SHEV) systems, so this function was also missing.

Eight of the skylights were located above the machine shop, and two above the shipbuilding hall. This meant the renovation had to take place in two separate buildings – without disrupting daily operations. ÖSWAG also wanted to renovate only the skylights, not the entire roof, making precise planning critical. 

One more challenge: the unique “eaves-ridge-eaves” skylight shape (like a low pyramid) made sealing and insulation tricky, requiring accurate slope measurements for a perfect fit.

After detailed consultations with VELUX Commercial, the decision was made to install energy-efficient Vario Therm skylights. Our partner, Strasser GmbH, built the wooden substructure, while VELUX Commercial supplied the products and handled installation.

Initially, the customer planned only to replace the skylights — but we demonstrated the value of integrating a Smoke and Heat Ventilation (SHEV) system, improving both safety and air quality.

Fall protection was ensured using a slimline LB-DSL steel safety net. For ventilation, different solutions were used: 8 dual flap units were installed for electric SHEV and comfort ventilation in the machine shop. In the shipbuilding hall 8 dual flaps for pneumatic SHEV (as existing piping could be reused), and 10 side flaps for fresh air intake.

The renovation was completed on time and without interrupting production — a clear example of successful teamwork.

The new skylights allow much more daylight into the halls. The added comfort ventilation improves indoor air quality. And the new SHEV system fills an important safety gap that was missing before.

The new thermally insulated skylights eliminate thermal bridges and help regulate temperatures in both summer and winter. Even better, the sealing system was designed to be reusable in future roof renovations, making the investment flexible and future-proof.