Housing costs under Universal Credit

Has anyone seen any explanation why all council tax reduction schemes include universal credit in it's entirety as income?

As it stands, housing benefit does not get counted, so why should the housing costs element of universal credit be counted?

Also, does anyone know what will be done with the housing costs element of UC in 53-week years?
The regulations clearly state that weekly payments will be converted to monthly rates assuming 52 weeks in the year - that would lead to quite a big loss for a 53-week year.