Many here do so either directly or indirectly.  

Do I need to include any info about my RE license in direct mail marketing materials? 

The 401k may not transact in any way that provides a direct or indirect benefit to you.Simply "protecting" your property from development as you state could be viewed as a benefit to you.  

But they do help maintain the value of the area indirectly by maintaining a certain standard for the area.

I'm not interested in direct ownership, but think this is a RE sector that will do well in the next 5-10 years.

I checked and its owned by a local guy that  I know indirectly. 

The pros far outweigh the cons, which include:Safer living & health conditions for tenantsA peace of mind for you as owner & for tenantsWhich can then in turn directly or indirectly, depending on your perspective & outcome, reduce vacany rates

If a disqualified party to your IRA is directly or indirectly involved in the transaction, then you would not want to do this.

This includes direct costs, subcontractors, overhead costs, and other indirect costs.

@Randy JonesGood question.Generally a father's IRA cannot be invested in his son's business as a son is generally considered disqualify party directly or indirectly.