EZ Retrofit Frequently Asked Questions

Tool Overview

What is EZ Retrofit?

EZ Retrofit is a free, do-it-yourself, Excel-based audit tool that gives multifamily property owners and managers an easy way to identify cost-effective energy and water efficiency upgrades that can help:

  • Reduce energy and water consumption and costs
  • Improve indoor air quality and tenant comfort
  • Attract and retain tenants
  • Increase property efficiency
  • Reduce maintenance and extend equipment life

Stewards of Affordable Housing for The Future (SAHF) developed this open-source, Excel-based software through collaboration with affordable housing owners and managers, ICF International, and Bright Power, Inc.

EZ Retrofit runs in Excel and streamlines the building review process. EZ Retrofit considers how building systems can work together to effectively reduce energy and water use and costs. EZ Retrofit can be used for small to medium-size multifamily properties in any climate zone.

How does EZ Retrofit work?

EZ Retrofit helps you identify and prioritize energy and water efficiency upgrades. Based on the information you provide about your building and systems, the tool identifies possible opportunities for improvement, lets you add or change information to validate those possible opportunities, and provides the data you need to make decisions about which upgrades you want to pursue.

What are EZ Retrofit "pathways"?

EZ Retrofit provides users two complementary pathways to identify potential building upgrades.

Can I transition between the EZ Path and the Advanced Path?

You can switch to Advanced Path at any time and all the data entered into the EZ Path will appear in the Advanced Path.

If you are new to EZ Retrofit, we generally recommend starting with the EZ Path. However, if you want to describe more complex systems in your building (e.g., multiple central heating systems) you should use the Advanced Path from the beginning. There are buttons in each path that will allow you to easily transition between the two.

What are some of the Advance Path ONLY features?

  • Enter customized local utility rates to replace the default state average rates used by EZ Retrofit.
  • Allocate the total units in the building according to the number of bedrooms per unit. 
  • Set up multiple heating and cooling zones for your building and assign heating and cooling systems to the different zones.  (This is a different approach to entering HVAC systems than is used in the EZ Path and requires that you clear any information previously entered in the EZ Path.)   
  • Change or override the baseline equipment and system assumptions that EZ Retrofit uses as inputs when estimating the building’s energy and water use to generate results.
  • Create customized proposed systems and upgrade packages.
  • Override the cost assumptions used by EZ Retrofit based on local prices and incentives.

Who can use the tool?

EZ Retrofit is designed for a wide range of users and with various technical skills and backgrounds. While you are not expected to have technical knowledge of how a building operates or of a building's heating, cooling, or other systems, the level of precision of the final set of measures correlates to the level of detail and accuracy of the information generated. The tool is primarily designed for multi-family property owners and managers but can also be used by:

  • Sustainability/ Energy Personnel
  • Maintenance Staff
  • Auditors
  • Lenders/Funders

How does EZ Retrofit work with mixed-use properties?

EZ Retrofit is designed to analyze multifamily residential buildings. The systems addressed and algorithms and assumptions used are for multifamily residential and not commercial or mixed-use properties.  If the commercial and residential space in the building are separately metered, then EZ Retrofit can be used to analyze the residential space by entering the building characteristics and utility data for the residential space only.  

Can I assess multiple buildings using EZ Retrofit?

EZ Retrofit analyzes efficiency on a building-by-building basis. For properties that have multiple buildings with similar systems you can:

  • Complete the tool for one building
  • Save a copy of the tool under a different file name
  • Update in the new file only those data points that are different for the new building

For properties that have multiple buildings with dissimilar systems or for entirely different properties you can:

  • Complete the tool for one building
  • Save a copy of the tool under a different file name
  • Use the ‘Clear Prior Entries’ button on the Welcome screen of the new file to clear all previously entered data and start with a blank tool

After completing the tool, you can combine the results of multiple buildings or properties in the Results screens. Learn more about this process and how to combine multiple versions of the tool in the User Guide.

What data does EZ Retrofit require?

Before beginning to enter data into EZ Retrofit, it is recommended to collect all of the information you will need to complete your analysis using the EZ Retrofit Checklist (also available through EZ Retrofit Tool). Some information will be available through written records and some will need to be gathered by inspecting the interior or exterior of the building. Because a range of different types of information are needed for the tool, property owners, maintenance staff, facility managers, and other individuals often collaborate to efficiently gather the needed data. 

Tool Access and Technology

Where can I get detailed instructions for using EZ Retrofit?

The EZ Retrofit User Guide provides detailed information about how the tool functions, the data required, the customizations you can make, and the information the tool can provide you. The User Guide can also be accessed from almost any screen within the tool.

What computer technology is needed to run EZ Retrofit?

EZ Retrofit is a Microsoft Excel-based program initially developed on 2010 Microsoft Excel software. The program should still run on older versions of the Excel; however, not all of the tool’s functionality will be available. The tool is being updated to run on Excel 2013.  If you encounter issues running the tool on Excel 2013, please email [email protected].

You will also need to have a copy of Microsoft Word installed on your computer to access the User Guide from the tool.

EZ Retrofit is designed to work on Microsoft Windows and will not work on Mac operating systems.

The tool sometimes takes a long time to do its load calculations. Is there something wrong?

EZ Retrofit’s calculations are complex. Depending on your computer’s processing speed, it is normal to have to wait a few minutes for the tool to make its calculations as you transition between the Envelope screen and HVAC screen in the EZ Path, and when generating the results and report. 

Utility and Building Data

Can I use the tool even if I don't have any utility data?

You can choose not to enter utility data if it is not easily available, and the tool will still provide a high-level assessment of your building’s potential for upgrades. For the most accurate results, enter either monthly or annual utility data. Otherwise the tool will not be calibrated and this may result in a loss of accuracy. 

How do I enter utility data when the tenants pay for their own utilities?

For tenant accounts, if all of the tenant usage information is available, enter the sum of all accounts as either annual or monthly (13 months data recommended) data. If only partial tenant information is available for tenant-paid utilities, you may prefer to extrapolate from a sample. Here are two ways to go about the extrapolation process:

- Extrapolation by unit type: If the building has multiple unit types (e.g., 1 bedroom, 2 bedroom, and 3 bedroom apartments), collect utility bill data from a representative unit for each unit type and multiply by the number of units of each type, then sum the total usage. If a larger sample is available, you may extrapolate from an average rather than using a single unit. With this method the billing dates for the representative units may not align, so use your best approximation for the billing dates. If tenants are on different billing cycles, you may prefer to enter annual data rather than attempt to align monthly data.

- Extrapolation from a single unit: Choose a single unit to represent all unit-types. For example, in a building with one, two, and three bedroom apartments, select a typical two-bedroom unit and multiply the utility usage for that unit by the total number of units in the building. Enter that total as the tenant usage for each month. Consider the number of occupants when selecting the unit size because a one bedroom unit with two occupants is likely to use more energy than a two bedroom unit with only one occupant. Use the billing dates for the unit from which you extrapolated.

Should I enter monthly data or annual data?

Monthly and annual utility data achieve the same level of accuracy when determining results. Please choose the option that is easiest for you based on the available records . If necessary, you can contact your utility to get up-to-date information about your building’s energy and water use.


How does the tool benchmark my buiding?

The benchmarking functionality in EZ Retrofit is developed based on the utility benchmarking tools available on the US Department of Housing and Urban Development (HUD) website.

Energy and water consumption data are voluntarily submitted for over 9,100 buildings by almost 350 Public Housing Assessment System (PHAS) nationwide. Regression analyses are performed on the datasets to see which of over 30 characteristics (e.g., building size, unit size, climate, building age, laundry type, parking, utility prices) are most closely linked to energy and water use.

EZ Retrofit’s benchmarking analysis is based on two metrics:

  • Site energy use intensity (EUI)
  • Site water use intensity (WUI)

These metrics are determined by calculating your building’s energy and water use as a function of the size of the building. The lower the value, the less energy and water a building uses per square foot. 

EZ Retrofit compares the EUI and WUI for your building with the EUI and WUI for a similar building based on the HUD data.  Depending on the results of the comparison, EZ Retrofit also will categorize your building as having the potential for significant energy and water savings through upgrades or as being fairly efficiently already. Even buildings that are already operating fairly efficiently can still benefit from entering data into the tool. Almost every building has some type of opportunity to improve energy and water efficiency and EZ Retrofit can help you to identify some of the most cost effective measures. 

How is EZ Retrofit different form Energy Star portfolio manager, and how can I use them together?

The EPA ENERGY STAR Portfolio Manager is an online benchmarking tool designed to track a building’s energy and water use intensity. For certain property types (including multi-family buildings), Portfolio Manager generates a 1-100 ENERGY STAR score to compare a property to similar properties nationwide. A score of 50 represents median energy performance, while a score of 75 means a building is a top energy performer – and may be eligible for ENERGY STAR certification. Portfolio Manager can answer the question of ‘how’ your building is performing, but it doesn’t identify exactly ‘what’ you can do to improve performance.

EZ Retrofit is an audit tool that provides specific upgrades that help users identify ‘what’ they can do to improve their building’s performance. Whether you use ENERGY STAR Portfolio Manager or EZ Retrofit’s modest benchmarking component to compare how efficient your building’s current performance is, EZ Retrofit will identify what specific ECMs are good opportunities at your building, and it provides potential upgrades for new systems and cost saving measures.

Building Systems

How can I tell if my windows are single or double pane?

It is not always immediately evident whether a window is single or double paned, but you can find out using the flame trick.  Light a candle, match, or lighter and hold the flame near the glass so you can see its reflection. If the pane reflects two flames, then you have a double-paned window. If the pane reflects just one flame, then it is a single-pane window.

How do I enter different Envelope sections (HVAC zones) in the tool, if necessary?

Information about your building’s HVAC zones (i.e., the space served by a single HVAC unit) is a critical input for EZ Retrofit. If your building has a simple HVAC configuration (e.g., a single central system or individual, in-unit systems), the EZ Path will be able to accurately reflect energy usage. For buildings with more complex HVAC configurations (e.g., multiple central heating and cooling systems), the Advanced Path allows for more accurate results.

- EZ Path. For central systems entered in the EZ Path, EZ Retrofit assumes that you have a single HVAC zone. If you have multiple central HVAC systems serving different Zones, you should use the Advanced Path.  Individual systems serving distinct spaces (e.g., in-unit PTACs) can be entered in the EZ Path. 

- Advanced Path. In the Advanced Path, you must create separate building envelope sections for each of the HVAC systems that serve your building. The purpose of this process is to more accurately account for the square footage of the building served by each HVAC system. The number of envelope sections you need to create depends on whether the HVAC system you plan to enter serves the entire building or only portion of the building. HVAC systems that provide both heating AND cooling to the entire building only require that you create one envelope section. Create a new envelope section for each ‘Location’ served by a unique cooling system or unique heating system.

Note:  The Envelope Screen in the Advanced Path is also where you name your heating and cooling systems.  When entering further details on these systems on the Heating and Cooling screen, be aware that EZ Retrofit sizes each system as if it serves the whole zone.  Therefore, the quantity entered on the Heating and Cooling screen for systems named on the Advanced Path Envelope screen should always be one (1).  

How do I enter different Heating and Cooling systems in the tool?

The way you enter multiple heating and cooling systems in EZ Retrofit depends upon whether you are using the EZ Path or the Advanced Path.

- EZ Path. Select ‘Individual’ for each system, complete all of the remaining fields, and then click ‘Add Another Heating & Cooling System’ and repeat this process until all systems have been entered. Select ‘Central’ if you have only one heating or cooling system that serves the whole building.  Within the EZ Path, you can only enter one central heating and one central cooling system. If a building has more than one system that you consider to be central, these systems should be entered as one representative ‘Central’ system in the EZ Path.

- Advanced Path. Enter information about your Heating and Cooling system(s), using one row on the table for each system. Use the red plus (+) or minus (-) icons to add and subtract rows for additional systems. Choose a descriptive name in the ‘Location Notes’ field to distinguish each system. Within the Advanced Path, you can enter multiple central systems. Refer to the Advanced Path guidance in the User Guide for additional instructions on how to do this.

What Heating and Cooling systems will EZ Retrofit allow me to enter?

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How do I select the quantity of my Heating and Cooling systems inthe HVAC screen when using the Advance Path?

EZ Retrofit calculates the Heating and Cooling system capacity to meet the cooling or heating requirements of the entire HVAC zone you entered in the Envelope screen. Therefore, the quantity of HVAC system should be entered as "1" when the system capacity is calculated by the tool.

For example, when entering Central or room Air Conditioners in the Heating and Cooling screen from the Advanced Path for a HVAC zone that serves 60 units with 60 similar capacity Central Air Conditioners, the quantity Central Air Conditioners should be entered "1" since the system size will be calculated to meet the cooling need of that particular zone.