My reply to what appears to be your duplicated query is as below,
As you correctly say housing benefit will only pay for accommodation no other costs and the declaration you mention is not used in every local authority.
Your landlord is required to provide you with written terms of your tenancy under S 20A of the Housing act 1988 if you are waiting for a declaration to be signed make your claim for Housing and Council Tax benefit now and submit any additional information later. If you have made a claim for JSA the DWP may have been in contact with your local authority to whom you should explain your position, the HB may be paid direct to you and you may need it to be backdated, do not delay.
13:11 Mon 18th Feb 2013