Cut plasterboard and insulation on Existing wall easiest?

[berne88]

I have a quick question, I'm going to make window sills this weekend after all the window replacements.

But on 4 walls there is additional insulation. So there is a kind of foam plastic, I think, a hard plastic material that is pink, and then a gypsum board, wallpaper, etc... I plan to cut it away so I can see to the stud, to avoid dealing with spacer washers.

What's the best way to cut it? And the easiest?

Best regards,

 

[sir_daniel]

The circular saw and then the reciprocating saw in there to remove that material, or if it's possible with a knife

 

[TeroM]

A circular saw in plaster creates a lot of dust. You can cut the plaster with a multi-tool, slower, more control, and much less plaster dust in the rest of the house.