From experience and following several financial books I have read, your monthly rent should not be more than 40% of your take home pay. I actually adjust that lower to 30% to make room for increase in rent and other unforeseen expenses.
So, for example if you take home N100,000 every month after tax, pension and other deductions that hit your payslip. 30% of that is N30,000 monthly and by 12 that is N360,000. Your rent should therefore be no more than N360,000 annually. If it is more than that then better pack out of the house because you are living beyond your means. Soon you will need to look for extra income to augment which in most cases might involve doing shady deals.
Also, most landlords in Nigeria still accept annual rentals which means you may even be obtaining a personal loan or allowance from your organisation to fund the rent. Sometimes these loans come with interest payment and if it is an allowance may incur some tax deductions.This is the more reason why you should stick to 30% or even lower. I know house rents are crazy in Nigeria but my good friend there is a location for everyone. Even the fishes have their location, that is why crocodiles live in swamps and sharks in Oceans.
So, if you take a personal loan at work to pay your rent then make sure your monthly deductions is no more than 30% of your income. Example, if you earn N100k monthly as take home or N1.2million annually then your rent should not be more than N360,000 which matches 30% of your N1.2million. You should then apply for a N360,000 loan from your office.
But please, if you borrow to pay for your house rent you certainly should know there is very very little room for borrowing again. In fact, that may just be it for borrowing for you. Any extra debt you have will surely rub you off a decent amount of savings.