Actual Savings: The difference in consumption before and after implementation of efficiency improvements. 

Additional Subsidy or Add-on Subsidy: A HUD incentive for resource-efficiency improvements in housing authorities. The housing authority obtains non-HUD financing to pay for the retrofit work and HUD provides an additional operating subsidy in an amount sufficient to amortize payments for the loan. The term of the loan is limited to 12 years. 

Allowable Utility Consumption Level (AUCL): The level of consumption of fuel, water and sewer usage to be used when budgeting for authority-provided utilities (using HUD Form 52722A). The AUCL is computed using the rolling base. 

Allowable Utilities Expense Level (AUEL): The estimated level of cost for utilities, computed using the HUD Form 52722A, for the upcoming year's budget. The AUEL is computed by multiplying the rolling base by the rates in effect at the time of the budgeting process. 

Authority-Provided Utilities: Utilities that are paid for by the housing authority rather than the resident. Authority-provided utilities may be either master-metered, master-metered with checkmeters or individual meters. 

Block Rate: Refers to a block or stepped rate structure in utility rate schedules.

British Thermal Unit (Btu): The amount of energy required to heat a pound of water 1 degree Fahrenheit. The Btu is the unit commonly used in calculating energy requirements. (It can apply to any energy use, not just heating water; for example, air conditioners are often rated by their Btu capacity.)  

Broker: A customer's representative. In this context, one who represents a utility customer's best interest with respect to finding the optimum energy and services package.

Burnertip: The final point of delivery of fuel in gas-fired furnaces, boilers and other equipment where the gas mixes with oxygen and the flame is produced. 

CCF: One hundred cubic feet of natural gas or water. For natural gas, a CCF is approximately equivalent to one therm of energy.

Calibration: The process of checking or adjusting a measuring instrument, such as a checkmeter. Checkmeters need to be calibrated periodically to ensure accurate measurement.

Central Tendency: A measure of the "typical" value in a collection of numbers or a data set. The mean (average) and the median are two different measures of central tendency.

Checkmeters: Submetering installed to record the energy use of individual apartments where master meters (or one meter per building) record the energy use of the entire building or series of buildings. 

Compliance Audits: Energy or water use audits required by HUD to be performed on housing authority buildings every 5 years. These audits are regulated by 24 CFR 965.304.

Consumption-Based Methodology: One of two suggested methods that can be used to establish utility allowances. (See also engineering-based methodology.) This method is based on actual consumption data from utility bills or checkmeter readings. These data are used to estimate the amount of energy or water a household should reasonably require.

Consumption Data: Records obtained from the utility company or from checkmeter readings that show how much energy or water was consumed within a given period of time.

Cooling Degree Days: A measure of the severity of the summer in a given locality: the more cooling degree days, the hotter the summers. Cooling degree days are the difference between 65 degrees F and the daily mean (average) temperature when the latter is more than 65 degrees F.  

Curtailment: A notice issued by a utility to a customer with interruptible service to stop or reduce the use of its product (gas or electricity) during peak system usage periods.

Customer Charge: See meter charge.

Data Set: A set of consumption records for individual dwelling units used to establish an allowance for a given allowance category.  

Demand-side Management (DSM): Utility programs developed to reduce demands on the utilities' generation, transportation, and distribution systems by improving the efficiency with which their customers use energy or shifting the time of energy use.

Design Temperature Differential: The design temperature differential, or design range, is the difference between the indoor temperature in winter and the outdoor design temperature in winter. The design temperature differential is used in calculating the space heating requirements of a dwelling unit under the engineering-based methodology.

End-Use: The functional application or use of a utility, such as space heating, water heating, cooking, lighting, operating appliances, or air conditioning.  

Energy Performance Contracting: See Performance Contracting.

Engineering-Based Methodology: One of two suggested methods that can be used to establish utility allowances. (See also consumption-based methodology.) This method is based on engineering calculations and other technical information that is used to estimate the amount of energy or water a household should reasonably require.

Equal Payments Plan: A payment plan offered by the local utility company to the resident whereby the seasonal variation in monthly bills is eliminated. A resident on an "equal payments plan" pays 12 equal monthly bills every year, even though utility use may go up or down with the seasons.  

Energy Savings Guarantee: See Savings Guarantee. 

Energy Services Agreement: A written agreement, between a housing authority and an energy services company outlining the work to be done under a performance contract. For housing authorities, it must contain the following elements: savings guarantee, scope of work, savings calculation methodology and financing terms. It must be approved by the local HUD office and should incorporate the HUD regulations for performance contracting.

Energy Services Company (ESCo): A company that specializes in managing energy and water conservation retrofit projects. The ESCo may perform any or all of the following services: auditing, developing packages of recommended measures, arranging financing, installing or overseeing installation of measures, resident and staff education, equipment commissioning, maintenance, measuring, verifying, and guaranteeing savings. 

Escalation Rate: The rate of change over time of a value such as energy costs. In many performance contracts, it is a stipulated rate of increase in utility rates used in energy savings calculations and guarantees.

ESCo: See Energy Services Company. 

Excess Savings: The difference between the amount needed to cover the debt in a performance contract and the actual savings.

Firm Service: Utility service that is provided to the customer at all times, even during peak usage periods such as very hot or cold weather. The utility is required to have enough capacity and product to serve the customer during these peak periods. The non-interruptible nature of this type of service results in a much higher rate for firm service than for interruptible service. 

Fuel Charge: A fuel charge is an adjustment to the cost of fuel based on the utility's actual cost for fuel. The utility is not allowed to make a profit on this portion of the bill and simply passes these costs through to the consumer.

General Purpose Bonds: Bonds that are financially certified by the entity issuing the bond. Bonds are seldom used for conservation projects because the high fixed costs of issuing this type of financing make it an expensive option for funding the relatively small dollar amounts needed for these projects. 

Heat Loss: The rate of heat transfer, in Btus per hour, from occupied space to the outdoors. Losses occur through walls, ceilings and floors of a structure, and through cracks around windows, doors, etc. The heat loss depends on the dwelling unit size, construction and design of the housing development, the physical condition of the development, amount of insulation in the walls and ceilings, the assumed indoor temperature, and various other factors.  

Heating Degree Days: A measure of the severity of the winter in a given locality: the more heating degree days, the colder the winters. Heating degree days are the difference between 65 degrees F and the daily mean (average) temperature when the latter is less than 65 degrees F.  

Housing and Community Development Act of 1987: Key legislation that establishes the regulatory framework for improving the energy efficiency in public housing by providing financial incentives for HAs to use non-federal funds for conservation retrofits and by allowing housing authorities to retain a portion of the savings they negotiate for rate reductions. 

HUD Form 52722-A: Used by the PHA to estimate utility costs for the upcoming year's budget. 

HUD Form 52722-B: Used by the PHA to reconcile actual utility costs with the estimated costs. 

HUD USER: An information source, established in 1978 by HUD's Office of Policy Development & Research (PD&R), for Federal Government reports and information on housing-related issues.

Hundred Cubic Feet (ccf): A common unit of measurement for natural gas and water. One ccf of natural gas is approximately equal to one therm of natural gas. One ccf of water is equal to 748 gallons of water.  

Individual Meters: One utility meter per apartment. Can be contrasted with a master meter where a single meter serves an entire building or complex. 

Interruptible Service: Utility service that is available at a reduced rate because the utility has an agreement with the customer that it can interrupt delivery of service during peak system demand periods.

Kilowatt-hour (kWh): The common unit of measurement for electricity. One kWh is 1,000 watt-hours, or the amount of electricity consumed by a 100-watt lamp in ten hours. One kWh is equal to 3,413 Btus.  

Local Distribution Company (LDC): The local utility company that provides energy distribution services (i.e., wires and pipes).

Low-Income Weatherization Assistance Program (WAP): A federally-funded program that provides conservation services and weatherization assistance to households with incomes of below 150 percent of federal poverty level.

Marketer: A power marketer is an agent for power generation projects that sells wholesale power or fuel. Marketers also may arrange for transmission and distribution of the energy provided. 

Master Metering: One meter that serves an entire building or a campus of buildings. 

MCF: A unit of measurement for natural gas or water that is equal to 1,000 cubic feet. At sea level, one MCF of gas is equal to 1,000,000 Btus.

Mean: A measure of the central tendency of a data set, the mean is the average value in a data set. It is determined by adding all the values and dividing the sum by the number of values in the data set.

Median: A measure of the central tendency of a data set, the median is the middle value in a data set, when the values are ranked from lowest to highest.  

Meter Charge: A flat rate assigned to each utility meter to cover the local distribution companies fixed costs in servicing the account, such as meter reading and billing.

Non-Allowable End-Use: An end-use whose consumption is excluded from the utility allowance because this use is considered to be a luxury rather than a necessity. It is left to the discretion of individual PHA to distinguish between luxuries and necessities based on local custom and usage patterns. For example, in some regions ceiling fans are seen as an allowable use because of the local climate, whereas in other regions such fans are viewed as luxuries.

Normalization: A mathematical process that adjusts for differences among data from varying sources in order to create a common basis for comparison. In the context of utility allowances, under the consumption based methodology, a PHA may use a fixed set of data on consumption for one or more years, with this data normalized (adjusted) using 30-year weather averages. The normalization corrects for the fluctuations in weather from year to year so that the allowances are calculated on more typical weather patterns.

Outdoor Design Temperature: The lowest outdoor winter temperature that could occur in a given location, based on a 99 percent confidence level. This temperature is used to determine the design temperature differential, which is used in calculating the space heating requirements of a dwelling unit using the engineering-based methodology.  

Peak Demand: The greatest electric demand reading during a specified period. Typically, an electric utility charges for the greatest monthly demand measured in 15-minute intervals. The unit of demand is the kilowatt (kW).

Performance Contracting: A mechanism to implement resource efficiency improvements with minimal up-front costs. It uses savings resulting from the efficiency project to pay for the work over time. 

Persistence of Savings: Energy or water savings that persist beyond an initial post-retrofit period. Lack of persistence may jeopardize the ability to re-pay loans in performance contracting, unless the ESCo provides a guarantee of savings. 

Per Unit Monthly (PUM): Authority-provided utility costs computed per apartment unit per month. 

Princeton Scorekeeping Method (PRISM): A utility billing analysis in which at least 12 months of energy consumption is adjusted for variations in weather. 

Project-based Utilities: See authority-provided utilities. 

Public Utility Commission: A commission at the state level that is comprised of either state-elected or appointed officials who regulate utilities such as electric and telephone utilities. The name for this regulatory may differ slightly between states. Public Service Commission is another common name. 

Requested Budget Year: The period of time following the current fiscal year for which the housing authority is developing a budget. 

Rolling Base: The rolling base period is the three-year period used to calculate baseline utility use when computing the Allowable Utility Consumption Level (AUCL) for a PHA facility. It is an average of the three years actual consumption prior to the current fiscal year. 

Savings Guarantee: In a performance contract, an ESCo guarantee that the average energy and/or water savings resulting from the conservation retrofit will be equal to that needed to cover the debt service and other fees associated with the project. An ESCo and a housing authority may chose to guarantee an amount higher than that needed to cover project costs. 

Section 8: The Section 8 program is designed to increase the housing choices available to very low-income households by making privately-owned rental housing affordable to them. It provides rent subsidies, either rental certificates or vouchers, on behalf of eligible tenants. These subsidies usually equal the difference between 30 percent of the household's adjusted income and the HUD-approved fair market rent (for certificates) or the PHA-approved payment standard (for vouchers).  

Shortfall: A negative difference between the amount needed to cover the debt service and other fees involved in a project (usually the amount of the guaranteed savings) and the actual savings. The ESCos savings guarantee should cover this shortfall. 

Step Rate: See block rate.

Space Heating: The warming of a dwelling unit to a reasonabe temperature in the wintertime. Space heating can be provided by any type of heating system; it is not limited to heating provided by portable space heaters.

Statistically Valid Sample: A data set that contains enough data to obtain a reasonable representation of the typical consumption for a given allowance category. The number of records (or sample size) required to make a sample statistically valid depends on how widely the consumption data vary among dwelling units within an allowance category.

Surcharge: The amount a PHA charges a household, in addition to Resident Rent, for consumption of checkmetered utilities in excess of the utility allowance, or for non-allowable end-uses.

Resident Rent: The amount paid monthly by the household as rent to the PHA. Where all utilities are supplied by the PHA, Resident Rent equals Total Resident Payment. Where some or all of the utilities are paid directly by the resident to the utility company, then Resident Rent equals Total Resident Payment minus the allowance for resident-purchased utilities.  

Tariff: The allowed rate to be charged a utility customer. A published, regulated rate schedule. 

Tax-Exempt Revenue Bonds: Traditional sources of low-interest financing for municipal agencies. Bonds issued by a tax-exempt entity. 

Tenant-paid Utilities: Where utilities are billed through individual meters and the project's residents are responsible for paying the bills.

Therm: A common unit of measurement of natural gas is equal to 100,000 Btus of energy. Depending on its quality, natural gas typically contains approximately 1,000 Btu per cubic foot. Therefore, a therm of natural gas usually is equal to about 100 cubic feet.

Total Resident Payment: Generally 30 percent of a resident's adjusted income.  

Transportation Company: A company that moves and delivers gas or electricity from a generation or production facility to a local utility company.

Unbundling: A term used to describe how consumers will be charged for electricity in a restructured utility environment. It is breaking up the current energy service package into separate components such as supply, transmission, and distribution.

Utility: Electricity, gas, propane, oil, water and sewer service, and garbage collection. Telephone service is not considered a utility for the purposes of this Website.  

Utility Allowance: Per-apartment-unit allowance for resident-paid or check-metered utility expenses that are set annually by the housing authority using a variety of means. The utility should be set to cover the utility costs of a reasonably conserving resident. 

WAP: See Low-Income Weatherization Assistance Program 

Wattage: A measure of the electric power required by a device such as a light bulb or appliance.  

Weatherization: Improving the thermal integrity of buildings by the installation of energy saving measures or equipment.