@Nick SansiveroI really don’t think big banks have to care about risk anymore with all the money they were given by the government at 0% over the last several years and ended up loaning it out at 4%+Even if they make risky moves at this point they have basically been told the only people they have to answer to are the shareholders.

Income Tax Return for an S Corporation, to report business earnings or loss and each shareholder’s portion of the corporate income or loss.* Limited Liability CompaniesA Limited Liability Company (LLC) with only one member can act like a sole proprietorship for tax purposes.

That structure would allow your retirement plan to become a shareholder of your building company. 

Keep in mind as LLC would ever disband, as sole proprietor, you would be the individual 'share holder' so that really makes no difference (unless going into dissolution of marriage, but that's an entirely different asset protection discussion) Really, first step should probably be the LLC with umbrella, suggested each subsequent property with it's own LLC.

So assuming that you and brother are 50-50 spilt on this property, you each hold (currently) a 50% share as joint shareholders/partnership. 

(I say that as you used the word "company") With that in mind here's why; Moving real property out of a  S/C- Corp is taxable when it comes to capital gains and a personal suit of judgment against you or one of your shareholders can filter through to the corporation.

As Sole Shareholder in a Corporation. 

Publicly traded companies buying up resi properies with overbids -- while they themselves have huge QvQ/YoY growth expectations set upon them by their demanding and fickle shareholders...what could possibly go wrong?

I know the the current shareholders of the llc personally.

The program cannot provide more than 5% of benefits to a class of individuals who are shareholders or their spouses and dependents [IRC Sec. 127(b)(3)].d.