Seniors Windows, Kippax - a small family business. They did a really excellent job [1], nice to deal with offered one price which they stuck to, no pestering with reductions in the hopes of getting the job after first quoting an higher price. It was the best spec. and the cheapest quote.
[1] just one niggle....They installed the window on our front flat sided single story bay, light oak, but left the bit between the top of the window and its roof white painted wood. The original paint work was rough and it looked awful, so they were rung to ask them why they had left it. The answer was that they thought the light oak all the way would have '...been too much and the white matches the soffits.' Anyway they readily agreed to return and sort it out.
They came back today and cladded one level of the surface over the window, but still left part of it as white painted wood - so another phone is on the cards, to get the final bit done.
Just one 4" X 10' bit of wood which would need regular painting left on the house and in time due to exposure will rot. Seems plain daft to me. If 'light oak' is 'too much', what's wrong with cladding it with white cladding - just to make it a finished job?
As already said a pretty good job, but spoiled for an 'apparth of tar. Unasked, today they pointed some brickwork which had been disturbed slightly during fitting.