I would suggest casting a 75mm concrete sill. If you don't have cast
sill's with ledges at the moment that is?

If you cast it so that the face is level with the bricks of the house,
i think it would look fine.
I wouldn't want to use spray foam and a plastic cover!

You can get concrete colouring. Probably brick red, but i have never
used these.
I think it would look best as plain concrete.

Regards,

Rich


Dave Plowman wrote in message ...
In article ,
Rick Dipper wrote:
If you are packing 75mm under the window cill, then if its downstairs
you will probably never see it. Sprayfoam and a covering of UPVc trim
(held on with silicone) seems to be the order of the day. You are going
to sprayfoam all round the window anyway.

Unfortunately, it's right in the eyeline of my favourite seat in the
garden, so it has to look good.

However, putting the trim at the top might look less obvious.

I don't want to lower the window position, though, and dropping it by
anything near 75mm would leave a gap to the internal tiles. And I don't
want to re-do all that.

If you really want to do bricks, you dont need full bricks, you can
slice parts out with an angle grinder, its time consuming though, and
not my favorite tool.

Not mine either for this job.