Swallow Heron 12x8 ThermoWood Lean To Greenhouse and Installation

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A Heron 12ft x 8ft wide Lean To greenhouse is a substantial greenhouse both in size and style. Inside you'll find so much space to grow an impressive variety of plants and from the outside the lean to will be an attractive enhancement to your house.

The frame has the familiar appearance of traditional timber but has been heat treated and is referred to as ThermoWood®. Without this process the wood may well warp and rot after a number of years.

However ThermoWood® has had its naturally occurring moisture and resin extracted and this means that it will not go out of shape and is highly resistant to decay, so no preservatives are required. Only Swallow use ThermoWood® in their entire greenhouse range.

To create perfect growing conditions inside the greenhouse for both gardeners and plants, there are two roof vents that are already fitted with automatic openers as standard. This means that you can be away from home, but they will still open to regulate temperature and humidity.

The lean to already has useful full length staging along one side and a high level shelf comes as optional, more staging can be added to form an 'L' shape. Toughened glazing lets in plenty of light and is sealed with silicone.

With such a generous width double doors can be located at either end, getting in and out of the greenhouse is therefore very easy, and for security there's a mortice lock.

All in all a very well specified greenhouse, built using quality materials that will last for many years.

12x8 Heron Lean To Features:

  • ThermoWood®: Heat treated Scandinavian timber that's rot and warp resistant
  • Glazing: 3mm Toughened safety glass
  • Roof Vents: Two with auto openers
  • Staging: On one side (L shape optional extra)
  • Doors: Double installed as standard
  • Glazing Bars: 58mm x 34mm finished size
  • Bottom Tongue & Groove: 12mm boards, 390mm long
  • Locks: Door has a mortice lock & aluminum handles
  • Glazing: All glazing is slid into a groove & sealed with quality silicone
  • Joints: All the cut shapes are jointed with a clear plastic H section
  • Capping: The ridge and top vents are sealed with a specially machined timber capping
  • Damp Barrier: 20mm black PVC section screwed to the bottom
  • Stainless Steel Nails: Used to fix all the tongue/groove boards
  • Delivery and installation included in price

12x8 Heron Lean To Dimensions:

  • Gable width: 2640mm (8ft 8ins) 
  • Length: 3840mm (12ft 7ins)
  • Eaves height: 1730mm (8ft 4ins) 
  • Ridge height: 3260mm (10ft 8ins)
  • Door width: 1200mm (3ft 11ins)
  • Door height: 1980mm (6ft 6ins)

Note: Larger 14ft x 8ft and smaller 10ft x 8ft versions of this Lean To are available.

Optional Extras for your Swallow Greenhouse

Staging along one side is included as standard in your Swallow GB Greenhouse, however, an additional High Level Shelf and Extra Staging on the end to make an L shape is an option below and can also be painted in a colour to suit. The Hunter Gutter and Downpipe Kit allows you to collect and reuse rainwater - the best water for all plants - this is available as an optional extra below.

Please Note: Imagery may show Dove Lean To's of a different size and optional extras that must be purchased separately. A suitable flat, level and sturdy base must be prepared before the delivery / Installation date to ensure a hassle free installation.

Select Your Options

Additional Accessories for your Greenhouse

  • with Ornate Black Door Handle


Build Design - Please Choose Your Required Door Position

  • with Door on the Left Side

  • with Door on the Right Side

Option 1: Would you like your Greenhouse Painted?

  • with Standard ThermoWood® Finish

  • with ThermoWood® Finish in BRACKEN


  • with ThermoWood® Finish in OLIVE


  • with ThermoWood® Finish in EARTH


  • with ThermoWood® Finish in LILY WHITE


Option 2: Would you like to add Extra Staging?

  • with ThermoWood® Extra Staging


Option 3: Would you like to add a High Level Shelf?

  • with ThermoWood® High Shelf


Option 4: Would you like to add a Rainwater System?

  • with Swallow Hunter Rainwater System in WHITE


  • with Swallow Hunter Rainwater System in BLACK


Option 5: Please choose a Delivery option -

  • including Delivery/Installation within Mainland UK

  • including Delivery/Installation within Scotland (North of Grangemouth)


Delivery Info


Inclusive delivery and installation is limited to UK Mainland excluding areas 15 miles further North of Glasgow. Areas further than this and Offshore Islands would require a custom quote. Please Contact Us here if this is the case.
A suitable, flat and level base must be prepared prior to the delivery and installation.

Price Promise

If you find any of our products in stock and immediately available, at our competitors we will try out best to match the price. We do not charge extra for delivery or installation, but if you find somewhere cheaper, please Contact Us so that we may try to match the price or beat it.


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