Adjusting comps to arrive at an accurate ARV

[Julio Ruiz-Cadalso]

Hi everyone,

First BP post so I wanted to ask one of my most pressing questions. I live in Houston, TX and will try to close on my first flip in (hopefully) 90 days. I feel uneasy about my ability to get an accurate ARV I can rely on. So my question is, how can I determine how much to adjust my comps for its differences from the "subject" property? I don't know how much one extra bedroom/bathroom is worth, or 300 sq.ft. less, or garage vs carport, etc...

I understand it can vary greatly depending on the area so if there's no way to answer this through the forum, maybe a better question is, where I can find this information (realtor, other investors, websites, etc...)?