It's a simple thing, and no doubt something we take for granted. "Born in a barn?" and "Don't slam it!" are phrases often associated with something that occurs at least once, often up to a dozen times, in every house in the world. What is it? A door! We only really notice them if they're squeaking, locked, expensive to buy, catching little fingers or slamming in the wind. However, there's a lot more to a door than one may think. There are the door hinges, door locks the handle or knob, and of course the material it's made of.

Hinges are possibly the most important part of a door, simply because without them the door would not open and close properly. An absolute bare minimum of one hinge is necessary, but to be honest, two is the realistic minimum and three or four are better. You can't just screw the hinges in and be done with it. The door needs to be balanced when it is 'hung' in its frame. A badly hung door will catch on the floor, leave a gap for a draft, not close properly or swing one way or the other without any help.

Door locks are important for security and privacy. Whether you want to keep people out while you're away, or keep them on the other side of the door while you're busy doing something personal, door locks are an essential, and relatively complicated piece of most houses, offices, schools, shops and almost any other building one cares to mention. There are lots of different brands ofdoor locks, and a reputable one is vital for the privacy or security required. Brands such as Dexter, Skulthai, Schlage, Chubb and Yale are known to be among the best.

The handle or knob is needed to open, and sometimes close, the door. Handles are long and look like levers. Knobs are round and twist. Generally, handles are easier to use and more practical, although they usually look a bit 'office-like.' Knobs usually look more aesthetic, but can be awkward when used with wet hands and, for some reason people frequently turn them the wrong way first.

What a door is made of can help more than just its appearance. A good strong door can insulate sound or heat and therefore offer more privacy, save money or reduce stress from annoyances. Some of the most beautiful doors that are remarkably attractive price-wise, can really be not that much good at all. They are often poorly constructed and made of cheap manufactured wood. A good door that is strong, will last a long time, and not warp needs to be priced accordingly to reflect its quality.

Maybe the next time you walk through a door, you might appreciate that it doesn't squeak or swing unnecessarily. And the next time you lock your valuables behind one, check that the door lock is a good model from a respected manufacturer.