In most building projects the most influential factor governing which switch and socket range you will choose, is budget. By the time the developer or home owner starts to consider switches and sockets however, the budget has usually been blown on another more pressing part of the project like the unforseen new roof or handmade Spanish tiles which 'just had to go in the new en suite'!
It's important to remember that the switches and sockets used throughout the house will have a big bearing on its overall aesthetic and as with everything else in a building or renovation project, preparation is key to achieving good results. Therefore the first rule in choosing a wiring accessory range is to start early.
Choose and purchase your switches long before you need them in order that they are on site and ready for the electrician to install. Far too often both homeowners and trades people begin this process a couple of days prior to the arrival of the electrical contactor. There are few of us who can afford to pay electricians to stand around on site drinking tea, so more often than not this results in the ordering of items because they are in stock and available for quick delivery rather than because they are what the client actually wanted.
It is vitally important to choose the exact range before installing any socket boxes, or 'first fixing'. In years past, socket ranges used the same depth boxes, (25mm for sockets, 16mm for switches). In recent years however, screwless and flat plate ranges have become much more popular. Indeed the majority of self build projects now take one of these two types rather than the traditional white plastic ranges used by contractors. Both Screwless and Flat Plate sockets usually require deeper boxes and it is frankly amazing how many electrical contractors fail to properly ascertain their clients' requirements at this stage and end up installing the wrong size box. The homeowner must then decide whether to rip out and re-chop all the wrong socket boxes or install a second choice range, which is invariably totally different to what they actually wanted.
One of the most common mistakes when installing sockets in the lounge and bedrooms is to put in too few. Switches tend to look after themselves because in most rooms, light switches are installed by the door. Sockets are a different story however, and as a fairly good rule of thumb, should be installed in every corner of the room which will allow for future room configurations. You don't have a desk and PC in that room right now, but when you do you can be sure it will naturally want to go in the one place you didn't install any sockets! I recommend always installing double sockets instead of singles and TV accessory points such as satellite, BT and CAT5 sockets in at least two locations in lounges and living rooms which will allow you to the room layout at a later date.
Remember to be realistic when choosing the finish. Sure, the highly polished mirror chrome switch looks amazing in the showroom, but how will it look when little Johnny or Hermione has put their mucky finger prints all over it. Some finishes carry 'usage' marks better than others. The finishes that require least cleaning and preserve their looks better than others are the white plastic ranges and any lacquered metal finishes. Finishes which are particularly sensitive to finger prints are polished chrome, black nickel and (oddly) the more expensive un-lacquered brushed steel finishes such as MK Edge.