A greenhouse is a wonderful way to get more pleasure from gardening, and create a whole new dimension outdoors.

A controllable microclimate, a greenhouse will help you grow delicious fruits and vegetables, as well as more exotic plants and flowers.

You'll be able to get ahead with your gardening, forcing bulbs and growing starter plants that can be transplanted come spring.

Increasingly, greenhouses are also places to relax and enjoy outdoor space, accommodating both plants and people.

This guide will take you through the different types of greenhouse, and help you decide which will best suit your needs.

Greenhouse frames are usually aluminium or wood. Here are some pros and cons:

Aluminium

Available in a choice of colours
Affordable, lightweight, rust-proof
Low maintenance
Easy to assemble
Heat loss is high in winter, unless insulated.

Aluminium can also come 'powder coated'. This relatively new technology gives a superior finish when applied to metals. A 5-stage chemical pre-treatment process cleans grease from the metal and provides a chemical key that helps the powder to stick. Bars are then individually hung onto jigs and sprayed with a dry powder of colour. This is charged with an electro-static charge and results in the powder clinging to the aluminium. Bars are then baked in an oven at around 200°C.

Wood

Looks traditional and beautiful
Wood retains heat well
High maintenance
Heavy - professional installation required.

There are three main kinds available: horticultural glass, toughened safety glass and polycarbonate safety glass.

Horticultural glass

Clear, so looks great
Affordable
Splinters if broken
Can be difficult to clean
Can break or crack as greenhouse ages, or with extreme frost.

Toughened safety glass

Exceptionally strong
Clear, so looks great
Crumbles like a car windscreen if broken
Tends to be more expensive.

Polycarbonate safety glass

Gives superior insulation as is made from two sheets of polycarbonate - like double glazing
Lightweight, flexible
Shatter proof
Opaque
Good light diffusion for even illumination
Vulnerable to wind damage
Algae can grow between the joined sheets.

Location is all-important when setting up your greenhouse. Here is a list of factors you'll need to consider:

Light
Choose a clear, sunlit area to take advantage of solar energy. Professional gardeners recommend 6-7 hours of direct sunlight during the winter months. Observe your garden before choosing the location, and consider pruning trees or hedges to get more light.

Heat
Locating your greenhouse closer to your house lets it benefit from any heat radiated from your house in winter. The closer it is to your home, the more convenient accessing it will be during bad weather.

Keen gardeners may want to install electric or gas heating (please note that these options require professional installation by qualified gas or electric technicians).

Other options include paraffin heat, which is relatively inexpensive and easy to install, but needs daily maintenance and has high running costs.

Propane gas and kerosene heaters are reliable, but are not so desirable as they produce a damp heat.

Bubble wrap can also be used effectively, but can look unsightly and results in a loss of light.

Water
Make sure your hose will reach to the greenhouse. More avid gardeners may want to consider installing a stand pipe.

Location
Keep your greenhouse away from features that may damage it, such as rapidly-growing plants or old, overhanging trees. Make sure the area is well-drained. Ensure easy access to your greenhouse, remembering you may want to get a wheelbarrow into it. Position your greenhouse as close to your house as possible, as it will give you easier access to mains power and water.
All greenhouses are vulnerable to strong wind. In the absence of shelter, a fence can be erected or a hedge planted to provide some protection in exposed places.

Size
Pick the biggest greenhouse you can afford for your space; this will give you more room to manoeuvre and more gardening options. Double- or triple-walled panels will provide extra insulation for tropical plants, but will be more expensive.

For any greenhouse except portable grow-rack or cold frame set up, you'll need a level, squared foundation. Foundations can be simple - ranging from a gravel or wooden floor - to a professionally constructed concrete base. Each type has pros and cons.
 
Concrete - durable, but draining must be considered and built-in, and this method can be expensive.

Wood - comparatively inexpensive as a foundation, but it will need regular treatment to prevent rot.

Brick - can be easily placed and spaced for stability and drainage.

You'll need a hard-wearing, solid and even floor to get the best out of your greenhouse. You'll also need a floor where water can drain away through your foundations, into the ground.

Options for this include concrete slabs, wooden decking, gravel, bricks, rubber matting, patio slabs and planking.

Getting the air circulation right is important so that your plants get the right balance of oxygen and carbon dioxide.

There are two kinds of vents - roof and side (or louvre). These can be manually, electrically or solar controlled. They work by letting hot air to escape via the roof, while cooler air is drawn in via the side vents.

Simple kit greenhouses have integrated vents, while more complex greenhouses require fans and vents to help circulate the air. Automatic ventilation systems are available, but can be pricey.

Shelving expands the growing capacity of your greenhouse, and can be installed along both sides and across the end. Staging is the support structure for the shelves.

You may wish to leave a side free of shelving, to grow plants in bags, pots or directly planted in the ground.

Other options include a potting table, with drawers and shelves for garden equipment and compost.

Before you buy, check your local authority's website for information on property lines, design requirements and planning permission guidelines.