If you are ever audited, all you need to show is proof of your payment and proof that you were liable for it (invoice + proof of partial ownership.)

I probably would not take such case if you wanted me to defend it in an audit - which tells you about my view of this strategy.

Our "business plan" (including audited financials and a thorough statement of the risks) is outlined in our Offering Circular, which is available on our website and via the SEC's EDGAR system.As @Gary Headrick says, startup stock is illiquid and very high risk.

We use a CPA for audits and tax returns but use either bookkeeper and in house resources for the daily/weekly tasks. 

However, this is assuming that your records are clear and organized, and given to him in a timely manner, so that he's not rushing or confused about what you've presented him.When I work on complex returns, I start with the headiest pieces first - the aspects that I know will need the most attention and will likely be under the most scrutiny from an audit perspective.

Or are you talking about unit walk throughs, checking roofs, foundation, plumbing, mechanicals, lease audits, etc?

I understand that the chances of getting audited are minimal, but I wanted to make sure I can defend/substantiate any deductions just in case!

@Spencer WetmoreI was in audit as well for my first few years in accounting (but I work in tax now), so I've felt the pain of everyone saying "oh, you're a CPA!?

That's the first principal element of a quality cost segregation study. https://www.irs.gov/businesses/cost-segregation-audit-technique-guide-chapter-4-principal-elements-of-a-quality-cost-segregation-study-and-reportA "mini" cost seg is basically a residual estimation, which is cautioned against by the IRS because it is generally inaccurate.

@Logan LarochelleUltimately, everything you report on the return can be questioned by the IRS...will they...Your role is to report an accurate return based on the tax laws provided to us.If the IRS questions anything you should say you are excluding the gain via section 121.Show them the closing documents on the day you purchased the home and the closing documents when you sold the home.Then to show that you lived in the home for 2 years - show them the receipts of utilities that are in your name.Likely they won't audit you - but in the chance that they do - you should at least have the documentation.