The first step is to plan the design – as with kitchens, your local supplier will run off a computer-generated plan based on the room's dimensions and your particular requirements.
If you're sticking with the same layout, measure your bathroom suite carefully before you go shopping for a replacement so that you know the new items will fit.
Re-plumbing and re-wiring will push the cost up so stick with the existing service points if possible – although this may be unavoidable if you want to change the position of the bathroom suite.
First decide on the right place for the bath and/or shower. If your loo is in your bathroom, decide where this will go and then position the washbasin.
Once the fittings are planned you can work out how to use the remaining space which, in modern bathrooms, may be quite limited. Some kind of storage, either cupboards or shelves – preferably both – is required for toiletries, cleaning products, toilet rolls and children's bath toys. If your bathroom is spacious you may also keep clean towels and your linen basket in there.
Choosing the bath and basin can be a time-consuming task. Even if you're not opting for something like a jaccuzzi or indoor hot tub, baths come in all shapes and sizes – standard oblong, rolltop, corner, curved, wider at one end than the other – and colours. Unless you desperately yearn for a particular colour it's best to stick with white. It's clean-looking, inoffensive and will go with any colour you decide to use for paint and furnishings.
Taps, too, come in a bewildering array of styles – choose a design that will complement your bathroom.
Before making your final decision on the bathroom suite it is helpful to check your plans with your plumber to see if there are any potential snags with the designs you have picked.
Even if your window has frosted glass make sure you have a curtain or blind with ‘blackout' lining unless you want neighbours or passers-by watching the silhouette of you bathing, washing or worse.
When it comes to decoration, remember to use – or specify, if someone else is doing the work – grout that is resistant to steam and water. Similarly, choose paint and wallpaper that will stand up to heat and steam – look in the ever-expanding ‘kitchen and bathroom' ranges.
Pale colours brighten a small bathroom, especially one with no natural daylight but it's fun to experiment with colour. And a large mirror across one wall, especially the wall opposite the window, will help make a small bathroom look and feel much bigger and lighter.
Floor coverings, too, come in all types of material and colour – but avoid carpet which is impractical and unhygienic in a bathroom. Vinyl, cork tiles or lino are good choices – warm underfoot and easy to clean. However, if the surface you choose is shiny always use a non-slip washable rug for extra safety.
If you're installing a shower – either as a separate feature or above the bath – investigate the different types before deciding which to choose. If you have high water pressure you could opt for a thermo shower which is connected direct to your heating system and keeps the water temperature even.
An electric shower system heats the water itself and is mostly used above the bath. Power showers will give you the ultimate shower experience, even if you have low water pressure.
Look for a non-slip surface in both bath and shower. Check with your plumber that the drainage can take the amount of water your shower is producing – an overflowing shower tray can cause serious problems.
Above all, the main thing to remember when redesigning your bathroom is – choose a design that works for your lifestyle.