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approx 50pct is in stock, and other 50pct in equities
I think people are afraid of your facts/question, but I'll bite. Stock is an equity, so your facts aren't very clear. I assume that "stock" is qualifying employer securities and the "equities" are regulated investment companies (mutual funds) so that the RICs will be liquidated to get the "cash." If this is the case, you may have a basic problem with ESOP qualification because of the requirement that ESOPs be primarily invested in QES, unless the ESOP is bifurcated into two or more parts (different plans really). Anyway . . .
Prohibited transactions should be a big concern when dealing with the purchase of a building. Is this building being used or purchased from a disqualified person or party in interest? Even if it is not, holding real estate in any qualified plan presents real issues about UBIT and just paying expenses, etc. There are several threads about the cons of real estate investments in qualified plans on these boards and the internet in general to get you started.