Berlin  - Summer is here and fine weather means spending more time in the open air and cooking outdoors. The simple barbecues, where at the most all you could cook were some steaks and sausages, are in competition with outdoor kitchen units where you can prepare an entire menu.

The range of mobile weatherproof barbecue grills and module elements for an entire outdoor kitchen is growing constantly.

The heart of any open air kitchen is the cooking hob. Gas fired grills are the most popular type where the gas bottle can be stored in a cupboard beneath the barbecue. Two burners are a minimum while four will allow you to expand your culinary skills.

Most outdoor kitchens have a lid or hood which also makes them perfect for baking bread, cakes or pizzas.

"It's very practical to have an additional side burner for a wok or cooking pot," advises Florian Muenkel, owner of an online outdoor cooking supply business in Germany. "For example, having an infrared back burner is the height of luxury."

Most grills have shelf space but with outdoor kitchens they can reach dimensions that make them suitable as work surfaces. They can be used to prepare meat, make salads or sauces.

That's what separates an outdoor kitchen from a normal grill: "The host does not have to spend time in the kitchen or shuttling between the outside and inside," explains Ursula Geismann, a trend analyst at Germany's Association of Furniture Industries.

The first big extra element an outdoor kitchen can have is a sink which is attached to the water mains by a pipe. "Wastewater can either be connected to a drain or a bucket depending on the unit's location," says Uwe Brzezek, a landscape gardener in Berlin.

A bucket will limit your capabilities but because you will probably only have a cold water supply, the sink will most likely only be used to rinse fruit and vegetables, for cleaning hands or keeping drinks cold. The big wash-up happens inside anyway.

The area beneath the outdoor kitchen's hob is used to store ingredients and cooking utensils on open shelves or in closed cupboards. Useful accessories to have are a towel rack, knife block or a magnetic strip on the side.

A bottle stand will provide a secure place for drinks. You don't often find a fridge in a garden as "it would have to be very well insulated to protect it against the sun," says Brzezek.

Most makers supply outdoor kitchens with a place to both barbecue and cook food. They are usually between 1.5 and two metres long and 65 centimetres wide.

One of the best selling outdoor kitchens on muenkel. eu is the "Classic 219 Barbecue" model from US firm Grandhall. It has four gas burners, a hood, a work surface as well as space for a gas bottle under the hob. It costs about 700 dollars.

Compact grill stations are usually mounted on two or four wheels for mobility. As long as the ground is relatively flat you can move it at will. "The grill can also be quickly moved into the garage or under the next shelter if you need to," says Muenkel.

In the barbecue season most people don't want the bother of having to move the grill which explains "why a weatherproof hood is the most sought after accessory," says Soeren Nilsen, spokesperson for the Danish barbecue maker Dancook.

The alternative to a grill station is a modular kitchen that can be custom designed to suit individual needs. Italian company bst makes deep fat fryers, gas cookers, chopping boards and a gas grill with a sink.

Their barbecue frames are made from painted steel and their worktops from hard wood. A combination of all four elements will cost just under 4,200 dollars. A free standing cupboard with ice box and work surface completes the unit for about 500 dollars.

If you want to be even more individual you can build your own outdoor kitchen from parts supplied at a DIY store or have a landscape architect design one for you. (dpa)