@Lateefah Mathews  there is already a huge living room , This area i want to convert is extra space

Amortized over 30 years you pay $535 per month, or $6420 per year.

(They’re obviously not going to move in, they’re just going stop paying rent.).

One issue with section 8 is it takes an additional month to get approved and the lease signed so even with higher rent, the extra month vacancy eats up most of the higher rent. 

Quote from @Kenya Glenn: Aloha BiggerPockets Community 🤙🏾,Is paying cash a bad idea if I plan to live in a property and rent out the other rooms?

As long as you have a fast title company, insurance and can pay extra for a rushed appraisal, you should have no issue getting closed quickly with any lender. 

I did a 15 year on an investment property - most will say do 30 and pay extra, its really a personal decision - if you are financially healthy and have very little risk with the extra payment you get a lower rate so go 20 years, but just recognize that equity is typically trapped in the property.

However there are cases where we pay for some.

I will sell this property in order to pay off debt.

Paying off a loan with the funds may not qualify.