It will almost certainly be possible to fit a pump but there are many factors which dictate how & where you fit it, what type/size pump you need, pipe work routes & if you need to increase the size of your HW/CW storage tanks.
It's impossible to advise with so little information & if it’s going to work & stay working for any length of time, the pump needs to be correctly installed. It’s not rocket science but neither is it as simple as sticking a pump in the attic (not the best place anyway) & I suggest you either call in a professional or do a lot more research before embarking on a DIY pump install.