Bathroom lighting is an integral part of the home lighting considerations. Unless you live in a studio flat, where the bath and shower unit are then subsumed within the living area, then the demands on lighting the separate bathroom will require some additional thought.
The first point to note is that bathroom lighting requires a mixture of ambient lighting and spot lighting. You need a certain level of ambient lighting to brighten the whole area, unless you are the sort that prefers to have a shower in the dark, surrounded by candles, every time you use the bathroom! You just need a small amount of general lighting so that you are able to see what you do. It is a good idea to use lights that do not require much electricity, so that the running costs are minimised. Some people simply have a ceiling light running on a energy saving bulb, and find that it suffices for them. Energy saving bulbs, however, take a bit of time to warm up to produce the required wattage of light, and if you were merely doing a quick visit to the bathroom you might find you might even exit it before the light is sufficiently bright, when it is still in the firing up process. For some people, however, they find this minor inconvenience negated by the fact that the running costs will be lower compared to a normal bulb.
You also need a bit of spot lighting in certain areas, particularly around the mirror. Why? It is so that when you are getting ready in the morning, you can see your face clearly in the mirror as the light falls on it to brighten it up. The light around the mirror should be of higher intensity than the ambient lighting provided by the ceiling light, so that the image in the mirror is more visible compared to the background. It is likely that without the mirror lights, your reflection in the mirror would be darker, because the light from the ceiling light would cast your shadow into the mirror.
Ideally, the mirror lights should be either above or to the side of the mirror, and angled slightly towards the middle, so the reflected light off the subject is diverted across to the other side of the face. If the mirror light is directly in front then it was cause direct glare; it is similar to watching a concert performance and having a backlight shoot right into your vision.
It is unavoidable that the mirror light be sites in close proximity to the user so it might also be a good idea to use translucent fixtures around the lamp so that the direct glare is cushioned.
If your bathroom is larger enough and you have certain decorative objects you wish to emphasise – or perhaps it is the bath itself – you may wish to focus some spotlights on these points of focus. These should be small focussed lights with higher lumens.
Bathroom lighting follows the same principles as other areas of the house. Consider the general lighting demands in addition to task specific lighting, and highlight points of interest. Consider also the light levels increased by reflective surfaces and glare as a result of siting. Selecting the fixtures for these may depend on the running costs. But if you get the balance right, your bathroom will be the perfect blend of function and design.