Mmm, I do quite a few in Caerwent and I don't have one under £12.00, in fact I am charging £4.00 per house more on one estate than one of my competitors.
Another guy I know goes all over South Wales and gets top prices regardless of location.
Don't price up by the hour, price up per unit.
Understand what you consider to be a single window, we all know some windows are huge, well break in down so that you are counting up in units.
Have a set fee per unit.
Mine for instance is £1.00 per window (or unit...if you see what i mean?)
If you are going to be trad only, don't forget that georgian and leaded windows take longer.
With a Georgian window with average sized panes I'd consider 12 panes to equal one unit, but I would charge £1.50 per unit.
You get the idea.
It is far, far better to estimate rather than guestimate.
Also of course, the higher you go, the more you charge per unit.
If you charge by the hour, getting at the real figure isn't that easy, it's no point thinking that you can do an average semi in 20 minutes, therefore you can do 3 an hour, you will rarely have hit, say, £24.00 per hour over a 5 day week if you decide to just charge £8.00 per house.
you won't work 8 solid hours a week, your average day will be about 6 hours or so, and yes, I know many work longer hours than that, I do myself for instance, but by and large most will only do about 6 hours a day, and some of that will be lost in traveling between accounts, writing out invoices, tea breaks, bad weather, various holidays and so on and so forth.
Arriving at what you REALLY want to earn an hour is not easy, and don't forget, there is a big difference between earnings and wages.
What you 'earn' per hour is not your personal income, it's your business income.
so as well as factoring in the 'actual' amount of time you are going to be up the ladder cleaning windows per day, you also have to factor in your business costs.
Not an easy thing to do when you are starting out, but just as a ballpark figure, you need to allow at least 5k for your business costs, don't kid yourself that it is only a set of ladders, a bucket and your tools...You can't do the job without a vehicle, and this is a real cost....
The very best of luck to you, as an experienced window cleaner you will know the job inside out, but it is vital you get your pricing strategy right!!!!
Ian