The external appearance of your garden office is important not only to you but your neighbours as well. Inside, you can make the space look as much or as little like a conventional office as you like.

Personal preference drives choice here along with cost and durability considerations. Starting at the top, roof shape determines roofing material to a large extent. If the roof is pitched, corrugated sheeting will give adequate cover, provided the ends are square but will look a little â ˜shed-likeâ ™. Clay or concrete tiles are likely to be too heavy for most structures but felt tiles are an option.

Timber shingles, thin rectangular â ˜tilesâ ™ made from cedar or oak are a very popular choice for summerhouses and small buildings. Naturally durable they can look very attractive particularly after they have weathered a little. Whatever roofing material is chosen it pays to install a waterproof membrane under the covering to ensure that water does not enter the roof space.

For flat roofs, options are essentially limited to membranes from the cheap and cheerful asphalt sheeting traditionally used on sheds to thermoplastic membranes which require specialist installation. The former will need replacing every 4-5 years and offer little protection from tears and rips or even the expansion and shrinkage arsing from heating and cooling. Although more expensive, a thermoplastic membrane should last 30 years.

The external walls will require cladding or a rain screen of some sort. Traditionally this would be tongued and grooved or shiplapped timber. The range of profiles is enormous and, if it is important to differentiate the building from a shed, careful choice of profile, width and timber can create a very attractive surface.

A more contemporary look can be achieved by leaving a small gap between boards though they should still have a slope on the short edges to shed any rain which is driven between them. Fixing the timber vertically rather than horizontally also makes a huge difference to the appearance as does using varying widths.

Just like with windows, softwood rain screens will need some form of protection which is likely to need replacing every few years. Durable or semi-durable timbers on the other hand will weather to grey over time and require little or any further treatment. The species chosen is largely down to personal preference; red cedar is a classic choice and is very light but also rather soft so if your building is in a place where it might be dented it might not be the best choice.

Larch is another possibility as is Douglas Fir though this will require some initial treatment. Oak is another rather expensive material and Chestnut another. For those happy with less traditional materials, galvanised steel sheet is an option as is almost any UV stable, waterproof material.

Inside, choices multiply exponentially and there is a great opportunity to personalise the appearance and use materials, colours and textures which would not be appropriate in a more domestic setting. Starting with flooring, carpet is probably the least appropriate choice. A harder flooring material which can cope with the occasional muddy footprint is better and, if underfloor heating is installed, this will be just as warm to bare feet as a thick carpet. Textured rubber tiles are very attractive though require specialist fitting and proofing. Modern linoleum and marmoleum also look very good as do some of the natural floor coverings such as sisal, jute, seagrass or coir. If you have a penchant for walking bare foot during the Summer, make sure the flooring you choose really is comfortable.

Wallpaper is probably not the most suitable choice for the walls but textured paints and coloured clay plasters can all give a much more natural look and help ensure the walls absorb and release moisture to create a more comfortable working environment.

More fundamentally, if you intend using shelves to store files and books not to mention printers etc., do make sure the wall structure is capable of taking the weight and you know what wall fittings to use.