Concrete is a very poor insulator.Try doing an energy audit.

That is probably extreme, but would guarantee and audit-proof position.Administering the assets of a plan is something you are allowed to do as the plan trustee.  

When HUD comes in to audit your files, you will be fined, or possibly criminally charged, if they see inconsistent applications of the policies.

Depending on total capital raise their may be audit requirements.  

Like a lot of IRS policies, it is not cut in stone either as to who's actually in business and who is not, they have a list of criteria to look at and from there, it is really up to the auditor in charge of your audit (if you're unlucky enough to get one!)

The issue is if you get audited can you demonstrate that you had the intent to hold, which I think in this case he can. 

@KIMBERLY LAND:  The paper process that @Jerry W. referred to is called lease audit if I remember it correctly.

The hard part would come justifying it if you got audited. 

I am in tax working on a specialization in estate, trust, and gift tax and she is in audit and is just waiting for the official CPA papers to come in the mail-woot!.

So, if you get audited, can you show that you intended to hold for rental or investment?