How much would it cost to enlarge a window?

[SadPander]

Hoping one of you lovely people knows the answer to this. Wondering if we could enlarge a kitchen window in a house we are thinking of buying. The room only has one small window so could really bennefit from some extra light, but no idea how much this would cost.

We had a medium size window in our kitchen and the cost to remove it, knock out brickwork, supply and fit a new UPVC DG window and make good (including fixing outside render) was quite expensive - about £900 including VAT. Window was about 150cm wide and 110cm high. I wanted to make it about 30cm deeper and keep the width.

Due to cost we didn't do it, bear in mind the above cost is absolute max as it might have included extra work top as well (I wanted the kitchen window will to be same height as work top so that work too and sill would be one piece if that makes sense).

I think it's not too expensive if you want to keep the same width. We enlarged one a few years ago by lowering the sill and although I can't remember the price, I seem to recall it costing less than anticipated.
Increasing the width means a new lintel which will push up costs considerably.

it depends if it needs structural supports or not.
we have a quote for enlarging 2 small windows so that we can fit double or triple glazing.
400£ (two men a day each) + materials (about 300, new lintel etc) + buildings regs because it's deemed structural.

• them new windows of course...

Depends a lot on the detail. If you need a larger lintel to make it wider then that makes the job more complicated. It also depends on what material you have outside, as what kind of window you are looking at. Get a few quotes from local builders as opposed to double glazing companies.
I would allow anything from £750 up to about £1500.