General Questions

REM is not supported on Apple® platforms; however, many users report using it successfully on iOS machines that are running Windows® emulators.

Yes, REM works on both 32-bit and 64-bit machines.

You should contact whomever provided you with the REM/Rate™ Software. If you received the software directly from NORESCO, please send an email to [email protected] requesting your User ID and Password. Be sure to include your name, and the name of your organization.

If you received REM/Rate™ from a HERS® Provider, the Provider needs to upload a Printing Permission File to our server before raters registering under the Provider can print. The Provider chooses the configuration of printing/draft/nonprinting for each report. Please contact your HERS® Provider if you have questions regarding the specific printing permissions you received after registering the Software.

Once we have received payment of the Annual License Fee, and a signed Software License Agreement or Amendment (if appropriate), the expiration date will be advanced one year on our web server. After we have updated our web server, re-registering REM/Rate™ will advance the date of the installed version.
REM/Rate™ can be re-registered by selecting Web Services on the Tools Menu.

System Requirements:

  • OS: Windows® 10
  • Note: Windows® 10 Users: REM will install into the default directory C:\Users\public. This will allow anyone with an account or any access level to use REM/Rate™. You may change the installation directory, but note that REM/Rate™ will not work in C:\Program Files if your access level is 'Standard User'.
  • CPU: 1 GHz or higher
  • RAM: 512 MB minimum
  • Disk: 1GB required
  • Help: REM help is a compiled HTML file and requires Internet Explorer® 4.0 or higher. It can be run as a standalone program by double-clicking on the file "REM_Help.chm", located in the same directory as the REM executable.
  • Screen Resolution and Fonts: To see all the screens in the program properly. For small fonts, a resolution of 800 x 600 or higher is required. For large fonts, a resolution of 1024 x 768 or higher is required.

The rating certificate shows the costs associated with the standard building (the specific building with standard conditions). The HERS® Guidelines state that cost values are displayed corresponding to those standard conditions. All other reports, including the performance summary, component loads, economic summary and the improvement analysis display the load, consumption, and costs of the specified building. If the specified building already uses all of the standard conditions, the cost shown will be the same as that shown on the Performance Report, or any of the other REM/Rate™ reports. If the building is not a standard conditions, then the costs shown on the Rating Certificate will vary from the other reports. The most common difference is the user entering set points different than those specified by the standard conditions.

The new HERS® Council Rating Method uses the Modified End-Use Load Method. The loads are modified by applying a ratio of the efficiency in the building to the minimum efficiency specified by the HERS® Guidelines as a function of system type and fuel type. If two or more systems are present in a building, each portion of the load is applied to its own specific ratio. You can think of it as the same method, but having one end-use per fuel type. For example: if a user specifies a gas-fired air distribution system servicing 60% of the heating load and electric resistance for the remaining 40% of the heating load. Then 60% of the heating load is applied to the ratio of the specified gas AFUE to the HERS® Reference AFUE (78 AFUE), and the remaining 40% of the load is applied to the ratio of the efficiency of the specified electric resistance (100%) to the HERS® Reference efficiency (which is a HSPF of 6.8, as the HERS® Reference mandates a conversion to an air-source heat pump).

Wood systems are calculated as any other system. However, as the HERS® Reference Guidelines do not directly specify reference efficiencies for wood systems, REM/Rate™ uses the values from the 1992 - 1993 column of "Table 2.a: Mechanical Equipment Rated Efficiency Values in the HERS® Guidelines for Uniformity."
Please note that although some of these systems are unlikely at best, they are legal inputs for REM/Rate™.

System Type System Efficiency Distribution Efficiency
Air Distribution 70% 80%
Hydronic 60% 80%
Unit Heater 70% 100%
Air-Source Heat Pump 70% 80%
Ground Source Heat Pump 70% 80%

Specify an improvement measure that has an existing condition of the fuel and system you are currently using, and a proposed system and fuel to which you are switching. Make sure you provide costs for both the pre- and post-fuels on the energy costs screen.
This process also works if you have multiple heating or cooling equipment systems specified.

Any basement which is not directly heated or cooled (and does not stay at the building's set points), should be entered as an unconditioned basement. REM/Rate™ does a complete energy balance on basement areas. If the basement is not directly heated, but does receive heat from duct losses and through uninsulated frame floors, do not enter the basement as conditioned. REM/Rate™ accounts for all of these losses.

These losses are actually attributed to the crawl space/unheated basement. The losses are dependent on the floor construction and the wall construction of the basement. Reporting the losses as either floor losses or wall losses would be misleading.

They would be the same IF the balance point of the building was exactly 65 degrees in the heating season and 74 degrees in the cooling season (not true of most buildings), if there were no solar gains, and if there were no other energy affects which were not directly related to 24UA DD calculation. No one has yet found the perfect normalized factor (a number which for a given building would not change from site to site).

The foundation wall with its total height, height above grade, depth below grade, and length fields describe the geometry of the wall, and nothing you enter in the library will change those values. The library only describes how much insulation is present, and where that insulation is.

If you have insulation which covers the entire interior of the foundation wall, from top to bottom, we suggest entering insulation top: "0 ft from the top of wall" to insulation bottom "0 ft from the bottom of wall", "above grade" and "below grade" options are available so you can create libraries which are height insensitive.

All entries pertain to the whole building. No entries pertain to a single unit. All entries including, but not limited to, area of conditioned space, number of bedrooms, wall areas, floor areas, window areas, number of lights and appliances, heating entries and cooling system entries pertain to the whole building being analyzed.
The number of units changes the assumption for DHW, and lights and plug load usage, but otherwise has no effect on the calculations.

It's a matter of which mechanical library you use. If you use the Heat Pump Library, REM assumes you are installing a ducted central system. If you use the Space Heating Library, and select the "Air-source heat pump" type, REM will not assume that a duct system is needed, although you can assign a duct system to it.

For additional assistance go to and enter your question or search the knowledge database for answers to your question(s). You may also join the REM Software discussion group on Google Groups™.

About: REM/Rate™ and REM/Design™ are trademarks of NORESCO, LLC. NORESCO is part of Carrier Global Corporation.