Hi Bucketnear, and welcome to the Forum.
I'm sure many members here would identify with your sentiments about being fed up with a 9-5 stressful job.
One thing most would agree on is that window cleaning gives a great deal of freedom, and stress is not something generally associated with this business!
Having been in a similar situation to yourself, I'd say that the most important thing for you to consider is the cost of starting your business.
If you decide to start off using ladders, the equipment cost will be relatively low, approximately £300-500 depending on exactly what you get. However, if you decide to start with a Water-Fed pole system, the equipment cost could be several thousand pounds. Even if you start with ladders, you will probably find that after a few months you'll want to move onto WFP simply because its safer and faster.
But more importantly than equipment, is a cost that many don't take into account properly. To build up a window cleaning business takes time. It could take say 8 months to develop a round that pays what you are getting from your present job. You need to live for those months as well, and the mortgage, rent, food and bills will still need to be paid.
I would be careful to make sure that you have enough to cover about 4-6 months living expenses while you establish your business. You could arrange a loan, or perhaps you have enough savings. But whatever happens, you dont want to be in a situation of having no cash in the bank and not enough window cleaning work to pay the bills. As soon as the bank sees your regular salary stop, you'll find it quite hard to get further credit. Its quite common in these circumstances for banks to end any overdraft arrangement without warning. Tell them your starting a business and need some leeway, and they'll be looking to lose your custom alarmingly fast. Generally speaking, banks don't like the self-employed, and any extra features you currently enjoy may well be suspended. Ironically, to obtain a business loan you often need 3 years of audited accounts. "But its a start up business!" cuts no mustard with the bank I'm afraid. They see that as not their problem. Some lenders however will offer finance on the strength of a properly prepared business plan, and especially if you've been able to put some cash into the venture from elswhere too.
Arrange the finance in advance, and set realistic goals for how much new business you expect to gain every month. Learn how to keep good accounting records, and most of all be prepared not to give up. You'll need warm clothes for the winter months, and good pair of sun-glasses if you go the WFP route.
Most areas of the UK are short of window cleaners, and Plymouth is no excepton. People will pay for a good personal service, its just a case of choosing your areas carefully, and canvassing (or leafleting) until you're sick to death of it. Then the actual job of window cleaning is not difficult, not stressful, and as long as you are reasonably fit, quite satisfying.
Later you can move onto commercial work, but ahhhh...one step at a time eh?
-Philip