Frequently Asked Questions

Should I buy wood or aluminium?

Whether you choose wood or aluminium is much about personal choice. Aluminium greenhouses are generally claimed to have less need for maintenance, but they conduct heat more quickly so the temperature range will be greater.

What is the best glazing option?

There are three options for glazing in most greenhouses - Horticultural Glass, Toughened Glass or Polycarbonate. A few greenhouses also use Perspex. Horticultural glass comes in 2'x2' squares, is quite brittle and when it breaks it shards into sharp and dangerous pieces. Toughened glass comes in large panes, is much stronger than horticultural glass, adding strength to a greenhouse. If it breaks it shatters like a car windscreen, leaving small granules of glass. Polycarbonate comes in large sheets. It is lightweight and flexible, but has a number of limiting factors: it can easily pop out when the wind gets up, it is opaque so you cannot see through it, it is a sandwich with cavities in it that fill with water and algae over time. And if that does not put you off polycarbonate it is also the most expensive option! Perspex is used where the design of the greenhouse requires a curved glazing shape.

What sort of foundation do I need?

Whichever foundation you choose for the greenhouse it must be level and horizontal. Some greenhouses can be erected direct onto earth. They are pinned to the ground using anchors sunk into concrete. But the choice of foundation really depends upon the level of humidity that you wish to have in the greenhouse and how exposed the site is. A concrete slab base will provide quite a dry, arid atmosphere whereas earth gives a higher level of humidity. The options include: a concrete slab, a concrete "picture frame" for the greenhouse to sit on with earth inside, paving slabs, earth, a brick foundation or a dwarf wall.

What size of greenhouse should I get?

Greenhouse growers always wish they had a bigger greenhouse! Your size requirements depend on what you wish to do in your greenhouse. The most popular size is approximately 6' wide x 8' long. But we suggest that you choose the largest greenhouse that your budget and garden will stretch to. Even adding 2' to the length makes a big difference.

What types of greenhouse are there?

There a three main types of greenhouse: Traditional, lean to and octagonal. the traditional free standing greenhouse is the most popular. An octagonal shape is useful for smaller spaces but also makes for a delightful garden feature. Lean to greenhouses sited on a south facing wall benefit from the heat stored in the wall over the day, giving a more constant temperature for growing plants.

Where should I site my greenhouse?

The ideal position is traditionally said to be with the greenhouse in a West to East line so that the sun travels along the southerly aspect for the day. But this is not always possible. The things to consider include: proximity to trees, shelter from the prevailing wind and from the North, access from the house and winter shadow from other buildings (the sun is 17 degrees lower in the sky over the winter). Ultimately, even if the sun can only get to the top of the greenhouse it will still heat the building up.