JOINDER AND ASSUMPTION AGREEMENT

Exhibit 10.6

JOINDER AND ASSUMPTION AGREEMENT

for

HOMEBANC CORP. and

HOMEBANC MORTGAGE CORPORATION

6/04 AMENDED AND RESTATED

SENIOR SECURED CREDIT AGREEMENT

Reference is made to the 6/04 Senior Secured Credit Agreement dated as of June 7, 2004 (as it may be supplemented, amended or restated from time to time, the “ Current Credit Agreement ”), among HOMEBANC CORP. (“ HC ”) , HOMEBANC MORTGAGE CORPORATION (“ HMC ” and together with HC, the “ Companies ”), JPMORGAN CHASE BANK and the other lenders party thereto (the “ Lenders ”) and JPMORGAN CHASE BANK, as agent and representative of the Lenders (the “ Agent ”). Terms defined in the Current Credit Agreement and used but not defined differently herein have the same meanings here as there.

Effective as of the Joinder Date, as defined below, COLONIAL BANK, N.A. (“ Assumptor ”), a national banking association, hereby joins in the Current Credit Agreement as a Lender. Assumptor hereby adopts and ratifies the Current Credit Agreement. Assumptor hereby accepts and assumes, to the extent of its Commitment and Advances, the rights and obligations of a Lender under the Current Credit Agreement arising on or after the Joinder Date. The Agent has furnished the Assumptor, and the Assumptor hereby acknowledges receipt of, true and complete copies of the Current Credit Agreement, the Custody Agreement and such other Facilities Papers as the Assumptor has requested.

From and after the Joinder Date the Assumptor shall be a party to and be bound by the provisions of the Current Credit Agreement and, to the extent of its Commitment and Advances, shall have the rights and obligations of a Lender thereunder to the extent arising on or after the Joinder Date.

Assumptor hereby confirms to and agrees with the other parties to the Current Credit Agreement as follows: (i) neither the Agent nor any other Lender has made or is making any representation or warranty or has assumed or is assuming any responsibility with respect to any statements, warranties or representations made in or in connection with the Current Credit Agreement or any other Facilities Papers or the execution, legality, validity, enforceability, genuineness, sufficiency or value of the Current Credit Agreement or any other Facilities Paper; (ii) neither the Agent nor any other Lender has made or is making any representation or warranty or has assumed or is assuming any responsibility with respect to the financial condition of the Company or any of its Affiliates or the performance or observance by the Company of any of its obligations under the Current Credit Agreement or any other Facilities Paper; (iii) Assumptor confirms that it has received a copy of the Current Credit Agreement and the 6/23/04 Amendment to Credit Agreement and a copy of the 6/04 Custody Agreement, together with copies of the financial statements of HMC dated December 31, 2003, pro forma post-IPO financial projections of HC, and such other documents and information as Assumptor has deemed appropriate to make its own credit analysis and decision to enter into this Joinder and Assumption Agreement; (iv) independently and without reliance upon the Agent or any other Lender and based on such documents and information as Assumptor shall deem appropriate at

the time, Assumptor will continue to make its own decisions in taking or not taking action under the Current Credit Agreement and the other Facilities Papers; (v) Assumptor appoints and authorizes the Agent to take such action as agent on its behalf and as its representative and to exercise such powers under the Current Credit Agreement and all related documents as are reserved or delegated to the Agent by the terms thereof, together with all such powers as are reasonably incidental thereto and (vi) Assumptor agrees that it will perform in accordance with their terms all obligations that by the terms of the Current Credit Agreement or any other Facilities Paper are required to be performed by it as a Lender.

This Joinder and Assumption Agreement shall be governed by and construed in accordance with the laws of the State of Texas without giving effect to any conflicts of laws principles that would require the application of the laws of another jurisdiction.

“ Joinder Date ”: August 4, 2004

Legal Name of Assumptor: COLONIAL BANK, N.A.

Assumptor’s Address for Notices:

Colonial Bank, N.A.

201 East Pine Street, Suite 730

Orlando, Florida 32801

Attention: Cathie Kissick

Phone: (407) 835-6622

Fax: (407) 835-6690

email: cathie_kissick@colonialbank.com

Commitment assumed: Twenty-five Million Dollars ($25,000,000)