It's important to realise that when the search engines visit your site and try to assess what your site is all about that the website is correctly optimised and focused on targeting potential customers seeking precisely the type of service you're offering. If your website is mainly aimed at window cleaning then ideally at least 90% of the site should be about that service, and not diluted with many other extra services such as pressure washing, gutter cleaning, driveway cleaning and carpet cleaning etc. That's not to say you can't mention these extra services (which you can add on your 'Our Services' page) but it's far more effective to have a seperate website focused on these individual services. Especially if you're relying on your website to gain more customers through online marketing.
Anyhow, here's one of the sites that I completed for a client in just a few days. It's only a two page site that cost £80 (I charge £40 per page) and already it's ranking on the first page of Google for the optimised search terms the client was aiming for.

Studio Arts website: http://www.studioarts-dtv.co.uk/ Email: mike@studioarts-dtv.co.uk