ASSIGNMENT OF CONTRACT

THIS ASSIGNMENT OF CONTRACT (the “Assignment”) is made November 1, 2007 by
TRIPLE NET PROPERTIES, LLC, a Virginia limited liability company (“Assignor”) to
APARTMENT REIT VILLAS OF EL DORADO, LLC, a Delaware limited liability company
(“Assignee”).

RECITALS

Assignor and El Dorado Apartments LLC, a Texas limited liability company,
entered into that certain Purchase and Sale Agreement, dated February 21, 2007,
as amended (as amended, the “Contract”) with respect to certain property known
as the Villas at El Dorado Apartments, located in Collin County, Texas, as more
particularly described in the Contract. Assignor desires to assign all of its
rights, title and interest in and to the Contract to Assignee.

AGREEMENT

FOR and in consideration of the premises and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
Assignor hereby assigns all of its rights, title and interest in and to the
Contract to Assignee.

Assignee by its execution of this Assignment hereby assumes all of Assignor’s
obligations under the Contract.

WITNESS the following signatures:

              ASSIGNOR:   TRIPLE NET-PROPERTIES, LLC,     a Virginia limited
liability company         By: /s/ Jeff Hanson         Name: Jeff Hanson        
Title: Chief Investment Officer     ASSIGNEE:   APARTMENT REIT VILLAS OF EL
DORADO, LLC,     a Delaware limited liability company         By:   NNN
Apartment REIT Holdings, L.P.,         a Virginia limited partnership
 
      Its: Sole Member  

 
      By:   NNN Apartment REIT Inc.,

    a Maryland corporation

Its: Manager

By: /s/ S. Jay Olander
Name: S. Jay Olander
Its: Chief Executive Officer