I always conservatively put 30 days though. 

Maybe I'm just conservative, but i suggest you reserve way more than $2500. or consider cash out refi on the single family home and use some of the cash buy another one.

This, even at conservative occupancy rates, would generate quite a bit of CF. 

I'm being extra conservative being new. 

If you're looking for additional safety, you could even split some of it to be invested into conservatively underwritten debt, so that if things go badly you can foreclose and recover some or all of your principal.

View report*This link comes directly from our calculators, based on information input by the member who posted.Hello, I am reviewing this potential rental property and I can’t figure if I am being too conservative with my expense assumptions.

No one looking to buy wants the business, they want the property which can and will be used to build an apt complex of at least 50 apts (on the conservative side)  and possible +100, which we've been told by the board is very likely since they want to build the area up.Does anyone have any experience in building a complex like that from scratch, i want to get into real estate and me (his son) this could be a huge step in the right direction, we have some investors we can sit down and talk with in the near future.

Here are the numbers:Purchase price: $130,000Down payment: $32,500 (25%) (conventional)                             $26,000 (20%) (private)Interest Rate: 5% (conventional with principal and interest payments)                         10-12% (private with interest only payments with balloon at 24 months)Appraisal value: $205,000 (this is what it appraised for before any work has been done)                             $280,000 (estimated after reno)Rents: $1,400 (already rents for this before purchase with 2 of 4 units occupied)             $3,000 (once units are renovated for occupancy)Estimated Expenses: $1,300/month (during reno)                                      $1,700/month (after refinance)Estimated Cashflow: $-100/month (during reno while I live in flip)                                     $800-$1,300/month (after refinance, estimates are depending on interest rates and conservative estimate)Let me know if you need more numbers for better clarity.

I went out of the gate at what I thought was a conservative number. 

Understanding market conditions is key, and getting to know the little things that have huge value influences, now if you have a cookie cutter home with plenty of sales it pretty easy, but if its an oddball with little market activity, it can be kind of a crap shoot, go with your gut and be conservative on the numbers, its way better to be off on the low side than way over valuing. good luck!