Section 990.160 - Overview of calculating formula expenses(a)General. Formula expenses represent the costs of services and materials needed by a well-run PHA to sustain the project. These costs include items such as administration, maintenance, and utilities. HUD also determines a PHA's formula expenses at a project level. HUD uses the following three factors to determine the overall formula expense level for each project:(1) The project expense level (PEL) (calculated in accordance with § 990.165 );(2) The utilities expense level (UEL) (calculated in accordance with §§ 990.170 , 990.175 , 990.180 , and 990.185 ); and(3) Other formula expenses (add-ons) (calculated in accordance with § 990.190 ).(b)PEL, UEL, and Add-ons. Each project of a PHA has a unique PEL and UEL. The PEL for each project is based on ten characteristics and certain adjustments described in § 990.165 . The PEL represents the normal expenses of operating public housing projects, such as maintenance and administration costs. The UEL for each project represents utility expenses. Utility expense levels are based on an incentive system aimed at reducing utility expenses. Both the PEL and UEL are expressed in PUM costs. The expenses not included in these expense levels and which are unique to PHAs are titled "other formula expenses (add-ons)" and are expressed in a dollar amount.(c)Calculating project formula expense. The formula expense of any one project is the sum of the project's PEL and the UEL, multiplied by the total EUMs specific to the project, plus the add-ons.