at my wits end :(

hi all, i have a 3 yr old male long haired tabby, who has has his bits 'removed'. i am have major issues with him weeing and pooing inside of a night time. he has been checked by the vet and all is clear. he has been like this since the first winter we had...... where i live i cannot put in a cat flap (not got permission) so i normally keep a back window open in the kitchen, as the nights get colder i shut the windows, and at the moment ive have it shut due to one of my other cats are recovering from breaking her leg and losing nerve sensation (is on the mend but not allowed out). i have got 2 cat litter trays down, but he doesnt use them. if he refuses to go out of the night he wees and poos anywhere but the cat litter trays.... ive tried alsorts tin foil, black bags, pepper, spraying the area but he keeps going back and using the area..... i use feliway as i have a nervous cat but my male is driving me potty, the house smells of wee, and every morning i seem to be cleaning up cat wee and poo before my young children are allowed downstairs.... is there any help out there before i shut him out every night so this stops PLEASE HELP!!!!!

I've had 20+ foster cats and recommend the following links. ALL of these things need to be considered-  not just medical issues. Sometimes it is a real process of mystery solving but I have yet to meet a cat I can't eventually train.

http://www.humanesociety.org/animals/cats/tips/solving_litter_box_problems.html

Jackson Galaxy is also a good resource on the litter box issues. Just really keep in mind - do not skip steps or make assumptions. It is often the last thing you consider.

http://jacksongalaxy.com/category/pee-poop-problems/

Good luck!