T-Shaped Wooden Greenhouses

About Our T-Shaped Wooden Greenhouses

T-shaped wooden greenhouses add a central porch that projects from the long side of the frame. This divides the interior into two growing wings. The porch doubles as a potting area, tool store, or seating space. We stock 20 T-shaped models from Swallow, all built from ThermoWood redwood pine. Every model includes 3mm toughened glass, 4 automatic roof vents, a 12-year warranty, and free installation.

Three ranges cover different widths and porch sizes. The Swallow Cygnet is 6ft wide with a 6ft porch and single door. The Swallow Mallard is 8ft wide with a 6ft porch and single door. The Swallow Swan is 8ft wide with an 8ft porch and double doors. Prices start from £8,847 for the Cygnet 6x15 and run to £14,222 for the Mallard 8x32.

Types of T-Shaped Wooden Greenhouse We Offer

T-Shaped Wooden Greenhouse Comparison

Matt's Pick: Best T-Shaped Wooden Greenhouse Best For: Serious growers who want dual zones and a 6ft porch without the premium of the Swan Why I Recommend It: The 8x15 Mallard is the one we install most. The 8ft width lets you run staging on both sides with a clear walkway. The 6ft porch handles potting and storage. At 15ft long, each wing gives you 4.5ft of growing space. Price: £9,919 View Product

How Does a T-Shaped Greenhouse Compare to a Standard Frame?

A T-shaped greenhouse gives you separate growing zones that a rectangular frame cannot. The central porch divides the interior into two wings, each with its own staging. This lets you keep propagation separate from established plants. The porch itself adds usable space without increasing the overall length. A Mallard 8x15 delivers more practical floor area than a standard 8x16 because the porch projects sideways. Read our wooden vs aluminium comparison if you are weighing material choices alongside the T-shaped layout.

What Is Included with Every T-Shaped Swallow Greenhouse?

• 3mm toughened safety glass — silicone-sealed into grooves on all panels
• 4 automatic Bayliss XL roof vents — wax-cylinder openers that activate at 15°C
• 2 front returned stagings — one in each wing, full length of the growing area
• Mortice-locking door — single on Cygnet and Mallard, double on the Swan
• 20mm PVC damp barrier — screwed to the base to prevent rising damp
• Guttering to all sides — integral aluminium guttering included as standard
• Free professional installation — our team delivers and erects the greenhouse
• 12-year frame and base warranty — covers structural defects and timber rot

Frequently Asked Questions

• How much does a T-shaped wooden greenhouse cost?

  Prices range from £8,847 to £14,222 including free installation. The Swallow Cygnet 6x15 is the entry point. Mid-range Mallard 8x15 models cost £9,919. The largest Swan 8x30 costs £13,818. Painted Cygnet models start at £9,137. All prices include ThermoWood frame, toughened glass, and professional installation.

• What is the difference between the Cygnet, Mallard, and Swan?

  Width and porch size are the main differences. The Cygnet is 6ft wide with a 6ft porch and single door. The Mallard is 8ft wide with a 6ft porch and single door. The Swan is 8ft wide with the largest 8ft porch and double doors. The extra width on the Mallard and Swan allows staging on both sides with a clear walkway between.

• Can I use the porch as a sitting area?

  Yes. Many customers furnish the porch with seating. The Swan’s 8ft porch comfortably fits two chairs and a small table. The Mallard’s 6ft porch suits a single bench or potting station. The toughened glass and ThermoWood frame create a warm, bright space that works well as an orangery-style retreat.

• What base does a T-shaped greenhouse need?

  A level concrete pad matching the full T-shaped footprint. The base must cover both the main body and the projecting porch. Allow 50mm extra on each side. Level tolerance is 10mm across the width. Most customers pour a 100mm concrete slab. Paving slabs also work if they are dead level. Our team checks the base before starting installation.

• How long does it take to install a T-shaped greenhouse?

  Most T-shaped models take 1–2 days to install. A Mallard 8x15 typically takes a full day. Larger models like the Swan 8x30 or Mallard 8x32 require a second day. Our two-person team handles the full build including glazing, staging, vents, and door fitting. We confirm the installation date 2 weeks before delivery.

• Do T-shaped greenhouses retain more heat than standard ones?

  Yes. The T-shape traps heat more effectively than a rectangle. The porch acts as an airlock, reducing heat loss when you open the door. ThermoWood also insulates better than aluminium. In our experience, T-shaped greenhouses stay 2–3°C warmer on cold mornings than equivalent-sized rectangular frames. See our glass vs polycarbonate guide for more on insulation.

• Can I extend or add a larger porch later?

  Porch extensions can be added at the time of order. Swallow offers 2ft, 4ft, and 6ft porch sizes on most models. However, extending the porch after installation is not straightforward. If you think you may want a larger porch, specify it when ordering. The cost difference between porch sizes is modest compared to retrofitting.