When fixing to plasterboard or drywall it's important to choose the correct fixing, or the item you are fixing could soon end up on the floor.
This house is built of brick and has been renovated and so instead of the walls being plastered they have been dry lined with the dot and dab method, where the plasterboard is glued to the wall with blobs of dry wall adhesive.
If you find that your walls are plasterboard and there is a solid wall behind then probably the best fixings to use are standard Wall Plugs, although this can be problematic if fixing heavy items. Rigifix wall anchors are an ideal solution for this problem-
Snap toggles are one of the best fixings that can be used on hollow plasterboard walls as they distribute the weight over a large surface area. Once the snap toggle is fixed the screw can be removed and the toggle will not move. These fixings are definitely one of the best fixings for hollow plasterboard walls. Some of these fixings can hold over 200lbs in 1/2 inch plasterboard
Toggler hollow wall anchors provide a good fixing in hollow plasterboard walls and can hold over 100lbs in certain plasterboards.
Spring toggles offer a good fixing in plasterboard but they have the disadvantage that if you remove the screw you loose the fixing as the toggle drops behind the plasterboard.
Redi drivers are ok for holding really light weight objects to the wall such as mirrors, you have to be careful if you attempt to use these on a wall that has been dot and dabbed as they can hit the brick behind, which makes a large hole in the plasterboard!