leaking window in loft

[MrBen]

Evening, how much approx. to reflash (i think )a window in my loft?
Or to replace altogether?
I can see the gap at the top of the window.
Its a terraced house in Burnley, lancs
cheers

 

[dann09]

Are you referring to a roof window of some kind, eg a Velux?
Does the window open?

Pics of inside and outside would help.

 

[catlad]

I have seen it a lot in century old terrace houses were the glass in the stairwell stylight starts to slide out due to putty drying out. Its possible to take the glass out and reseal it. However it gets repaired it will probably cost about £100.