Total Climate Control. No Compromises.
NP Structures will unveil its new Constant Tension Retractable (CTR) Roof System at IPM Essen, where the team will be exhibiting in Hall 7, Stand 7A28.2.
Developed to give growers greater control over light and airflow, the CTR system is engineered for continuous adjustment, rather than simple open-and-close operation. A constant-tension roll-off mechanism allows the roof to be positioned anywhere along its travel and held securely in place – even in changeable or windy conditions.
This enables growers to fine-tune environmental conditions throughout the day, adapting precisely to crop requirements, weather patterns, and seasonal variation.
“We designed the CTR system around the idea that real climate control isn’t binary,” says Jack Wolfenden, Director at NP Structures. “Growers don’t just need to open or close the roof – they need to hold it exactly where it delivers the right balance of light, airflow, and protection. Constant tension is what makes that possible.”
By providing instant access to natural light and airflow, the CTR roof allows crops to be hardened off in situ, reducing the need to move plants, allocate additional space, or increase labour. The roof covering offers 84.4% light transmission, supporting strong crop development while allowing exposure to be moderated as conditions change.
“What stood out during development was how much simpler it makes day-to-day growing,” adds Wolfenden. “Hardening off can happen in the same structure, cutting labour and reducing risk at a critical stage of production.”
When closed, an integrated interlocking ridge cowl forms a wind-tight and water-tight seal, with automatic sealing during closure and features designed to prevent debris and moisture ingress. When open, the rolling action naturally sheds water and debris, helping extend the life of the cover.
Visitors to IPM Essen can see a live demonstration model of the CTR system on the NP Structures stand.
📍 IPM Essen
Hall 7 | Stand 7A28.2
The CTR system is a retractable greenhouse roof designed for continuous climate control. Unlike systems that simply open or close, the CTR roof can be positioned anywhere along its travel and held securely in place using a constant-tension roll-off mechanism.
Yes. The CTR roof is specifically engineered to be held at any position, allowing growers to fine-tune light and airflow throughout the day. The constant-tension design keeps the roof stable and secure, even in changeable or windy conditions.
Constant tension ensures the roof remains evenly loaded during movement and while stationary. This reduces fabric flutter, improves stability in wind, and allows the roof to stay exactly where it’s set – rather than drifting or needing to be fully open or closed.
By providing instant access to natural light and airflow, the CTR roof allows crops to be hardened off in situ. This removes the need to move plants, allocate additional hardening-off space, or increase labour at critical stages of production.
Yes. When closed, the CTR system forms a wind-tight and water-tight seal using an integrated interlocking ridge cowl. Automatic sealing, galvanised steel overlap, and brush strips help prevent debris and moisture ingress.
The roof covering provides 84.4% light transmission, supporting strong crop development while still allowing growers to moderate exposure as conditions change.
The CTR system can be seen live at IPM Essen, where NP Structures will be exhibiting a demonstration model.
📍 IPM Essen
Hall 7 | Stand 7A28.2
After the show, videos and additional demonstrations will be available via the Northern Polytunnels website.
The CTR system is designed for professional growers who require precise environmental control, efficient workflows, and robust performance across varying climates and crop types.
