There seems to be a bit of a convention for back doors, that they usually have a half window and usually only have a single simple lock.
Unfortunately criminals know that an easy way to break in is to break the small window, reach in, and unlock the door.
It’s not as though you really need the window as most back doors are in the laundry which isn’t a room you spend a lot of time in, and it usually has a window.
My preferred approach is a solid back door with two locks fitted at least 300mm apart.One a deadlockas I am always a bit suspicious about Construction Locks
Not only is this more secure, and offers better insulation but its likely to be slightly cheaper. Also you can always put a couple of coat hooks on the back of the door to hang your gardening clothes.
As you can see from the photo of my back door I remembered to specify the double locks but didn’t think to specify ‘no window’. I will remember next time!
More on doors including 24 pages of Check Lists for your new house choices in the‘Selection / Pre-Start Guide’