Real estate can be purchased the devil is in the details and they can be tricky.
A 2nd home for the good doctor, err I mean client. is almost certainly going to run afoul of the prohibited transaction rules.
Don't forget your annual fair market appraisal, possible annual audit requirements if you are a small plan that no longer qualifies to waive the audit, and your increased bonding requirements.
Suggest your client consults with qualified ERISA counsel who deals with real estate transactions to make sure they know all the PROS and CONS of real estate investments in a qualified retirement plan and to make sure they are not running into a prohibited transaction and the plan will have enough liquidity to met all of its distribution needs.