You can definitely hang things off plasterboard. My whole house is plasterboard dot and dab, we’ve wall hung flat screen TVs, shelves, large artworks, radiators etc. My husband has done it so it’s definitely DIY-able.Thanks I'll take a look. I've had a carpenter & they've said due to the plasterboard walls I can't put in a unit or nails. I also don't want the expense of a big job or a builder in blocking up the window, looking for quick easy fix!
Look up heavy duty plasterboard fixings - this is one type https://www.geefix.com/