i'm the same i find it hard to drink in the house but i fill up a 750ml bottle 3-4 times in work so I usually have around 3 litres in work which is a good amount then i make sure i have 1-2 tall glasses of water at home as i always have a glass of coke zero too so i make myself have at least one glass of water first so that way i make sure i get enough water. i think as long as you're having enough in work then maybe you dont need as much when u get home, its the days off i find more difficult!
I find it easier if i drink out of a bottle. I bought a lovely sports bottle from Asda and i dont even seem to notice i'm drinking and before i know it the bottle needs reflilling. Sometime about a big pint glass of water that just makes me feel bloated but put that same volume in a bottle and i dont seem to mind haha