I would think that having a cash cushion to cover unplanned expenses is a wise choice but really have no idea how much is enough. 

We also cushioned the construction budget to allow us to pay the carrying costs out of the loan itself.

The more you save, the better your financial cushion, which can be essential for unforeseen expenses in real estate.Keep Educating Yourself: Continue your education in real estate.

Just get close and build in some cushion on your profit.

You also need emergency fund/reserves set aside as a cushion before you purchase your first property. 

Its more risk for the lender - the lender's main remedy to a default (if you stopped paying) is to foreclose and own the property, and the down payment is essentially the "cushion" on value to protect them from taking back a property that is worth less than the property

Do you plan to flip, rent, etc Since you're just starting off I would emphasize that you need to buy right...buy under market value to give yourself a cushion....Make $ the day you buy!

My experience is that they want the deal to show good financials, they don't want to finance dumps - even if your plan is to renovate, have cushion in the appraisals based on going CAP rates, and you have to show up with at least 20% down.

I have always been under but gv me cushion when going to lenders, they love it..

That's a deal killer unless a certified electrician can do an analysis and finds that the lines can handle the amount of amps that are being pulled with a nice cushion on top.