What do you factor into your estimates?

[Daniel Cuevas]

When looking to purchase a property what should I look at and take into account in regards to making the purchase price make sense?
I'm planning on house hacking in California, hopefully an duplex or triplex and I want to make sure that I'm taking the right things into account. 

[Lucas Machado]

@Daniel Cuevas I'm not sure if you have a background swinging a hammer (I do not), so for our business we primarily use a price per square foot of $30.00 per square foot for major rehabs to determine if we are "in the ball park" with the seller before spending considerable time analyzing the property.  There is always hundreds of properties to analyze, so if your spending anymore than 10 minutes putting together an initial offer it will take up a lot of time on owners that may have no interest in selling at your price.  

If we are close or in agreement with the seller, we walk through the property, take detailed pictures, and if it is considerable work consult a trusted GC.  I certainly would not make major renovation decisions without a walk through with a good GC/inspector.  My point is, not to discourage you from making good estimates, but don't get too hung up on math from your desk as when you visit the property/walkthrough with a GC/inspector expectations often will change even if you spend hours calculating on your own.

Good example: we entered a contract on a 950 sq. ft. property last week that appeared to be CBS from our Google streetview and based on our conversations with the seller who did not have much information as she lived out of state.  Month-to-month tenants allegedly paying $1,000/month.  We estimated about $30,000 repairs.  When we visited the property it was wood frame with extensive termite damage, loose and old electrical wiring, and collapsing roof.  Tear down.  Went from $30,000 repair 3-6 month project, to a $125,000 year long construction project.