When choosing a polytunnel, most growers focus on width, wind rating and cover type. But height is just as important.
The internal height of your tunnel affects airflow, temperature stability, crop selection and how comfortable it is to work inside. Importantly, height is determined by the frame, not the cover. Whether you choose greenhouse plastic, netting or shade cloth, the dimensions remain the same.
This guide explains how tunnel height varies depending on width and frame tier, and when upgrading to a Premium kit makes sense.
Wall Height: Starter, Elite & Pro vs Premium
For Starter, Elite and Pro kits, wall heights range between 1.5m and 1.8m, depending on the specific configuration.
Premium kits increase wall height significantly, ranging from 2.2m to 2.5m.
This extra wall height provides:
- Improved side clearance for taller crops
- Better airflow and heat rise
- More usable growing space along the edges
- A more open and comfortable internal environment
The Premium kits achieve this through larger footings and increased structural adjustment, allowing the frame to sit higher while maintaining strength.
Apex Height by Width
Apex height increases as tunnel width increases. Wider tunnels naturally create higher overhead clearance.
4m Wide Tunnels
- Starter / Elite / Pro: 2.8m – 3.1m apex height
- Premium: 3.5m – 3.8m apex height
4.9m Wide Tunnels
- Starter / Elite / Pro: 2.9m – 3.2m apex height
- Premium: 3.5m – 3.8m apex height
5.8m Wide Tunnels
- Starter / Elite / Pro: 3.1m – 3.45m apex height
- Premium: 3.8m – 4.15m apex height
The wider the tunnel, the greater the central headroom. This is especially important for trellised crops or growers using internal infrastructure such as irrigation lines and support systems.
Why Height Matters
Height is not just about standing room. It directly affects performance.
- Temperature Control: Taller tunnels allow hot air to rise further above crop level, reducing plant stress.
- Air Circulation: Increased volume improves airflow efficiency.
- Crop Flexibility: Ideal for tomatoes, cucumbers, climbing plants and fruit trees.
- Machinery Access: Higher walls provide easier access for equipment.
If you are growing tall crops or planning a long-term commercial installation, the Premium height upgrade is often worth considering.
Does Cover Type Affect Height?
No. Height remains the same regardless of what cover you choose.
The cover changes the growing environment, but the frame determines structural dimensions.
Choosing the Right Height for Your Setup
If you are a backyard grower producing low-height crops, the standard 1.5m–1.8m wall height may be perfectly suitable.
If you are growing trellised vegetables, fruiting crops or want improved airflow and long-term flexibility, upgrading to the Premium kit with higher walls and larger footings provides additional performance and comfort.
Call or email us at sales@greenhousepolytunnels.com.au or 0418 438 774 and we will help you select the right width and height configuration for your growing goals.
