2025 Hotfix 37 End of October 2026
- Bug Fixes and Stability Enhancements:
- Remove spurious garbled characters from reports.
- Fixed an issue where ducts in sealed attics were not being included in the thermal envelope for ECCCNYS 2025.
- Added an error for when a duct system using only Total Duct Leakage shows zero leakage but does not claim the RESNET testing exception.
- Fixed an issue in Improvement Analysis where adding an ASHP causes an error in the duct system to be reported
- Fixed the IECC 2024 and ECCCNYS 2025 reports to display all mandatory requirements. The overall PASS/FAIL result now correctly incorporates these mandatory requirements.
2025 Hotfix 36 Late October 2026
- Bug Fixes and Stability Enhancements:
- Fixed the hourly engine export so wall construction type, wall emittance, door orientation, foundation wall type and slab thickness are taken from the model instead of defaults. Mass-wall and block-foundation homes rated with the hourly engine will see small score changes; wood-frame homes change slightly because of the emittance correction.
- Fixed an issue in the HVAC Grading record where the graded total duct leakage I or II on that record was set, and left the design or measured blower fan airflow blank, would cause the system to erroneously give a 25% airflow bonus instead of a 25% penalty.
- Fixed an issue that could incorrectly calculate infiltration for some attached dwelling units at the 0.30 CFM50/ft² compartmentalization threshold, affecting HERS/ERI results.
- Fixed an issue that could incorrectly model infiltration in certain multifamily dwelling units with exhaust-only ventilation, affecting HERS/ERI results.
- Fixed typos and removed IECC terminology from ECCCNYS 2025 reports
- Fixed a crash in the ECCCNYS 2025 TC Compliance report
2025 Hotfix 35 Mid October 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue that caused roofs in buildings with vented attics to be excluded from the UA tradeoff incorrectly
2025 Hotfix 34 October 2026
- New Features:
- New Trial Registration dialog
- Export to Weatherization Assistance Program
- Bug Fixes and Stability Enhancements:
- Fixed an issue in the parsing of certain UDRH files that cause an error in the reference building
- Fixed an issue in the UA tradeoff for IECC 2021 and 2024 where the roof was wrongly included in the thermal envelope for a vented attic.
- Renamed "HERS" to "ERI" in all ENERGY STAR reports
- Fixes to 2025 ECCCNYS reports:
- Added mandatory requirements for ducts in conditioned space
- Updated wording for the reports
2025 Hotfix 33 September 2026
- New Features:
- Added ECCCNYS to the HERS Certificate Criteria section
- Bug Fixes and Stability Enhancements:
- Fixed the following issues in the HERS Reference Building Summary Report (No change to ERI / HERS score):
- Ceiling & Attic: Any ceiling not matched to an attic gets its own row
- Frame Floors: Ceilings are no longer listed as framed floors
- Slabs: Full and On-Grade perimeter now come from the matching Rated Home slab, since the Reference Home keeps the Rated slab geometry. A slab with no matching Rated slab shows N/A
- Updated Quick Analysis to use the selected 301 standard instead of defaulting it. This makes the HERS score consistent across all reports
- [Affects ERI/HERS scores] Fixed an issue where entering 0.30 CFM50 per sq ft of shell exactly for an attached dwelling unit could lose the Aext reduction of ANSI/RESNET/ICC 301 Table 4.2.2(1); resulting in a potentially large increase in the ERI score. The fix restores the Aext reduction and possibly lowers the HERS / ERI score
- Fixed an issue where an hourly OS-ERI rating, the Comparison Analysis reports show incorrect Reference Home data:
- Building Summary – "HERS Reference" renders the as-designed (Rated) home instead of the 301 Reference Home
- Energy Cost and Feature – Reference column
- Reports envelope components not in the model (Floor, Sealed Attic, Vaulted Ceiling)
- Pulls the vented-attic roof-deck R-value for "Ceiling w/Attic" instead of the flat ceiling R-value
2025 Hotfix 32 Late August 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue IECC 2021 UA Pass/Fail in Quick Analysis is inconsistent with the corresponding IECC 2021 reports
- HVAC Grading is now syncing properly in the summary page when duct values changed in the Duct System page
- Fixed an issue where opening a 16.0.6 building file with measurement library in 2025 HF 31 crashes REM
- Fixed an issue in the parsing of certain UDRH files that cause an error in the reference building
- Fixed an issue where the ERI value is missing from the IECC 2024 and ECCCNYS 2025 certificates
- Fixed an issue with the UA calculation for AGWs for IECC 2021 where "vented attic -- ambient" was inadvertently being counted in the total wall area
2025 Hotfix 31 August 2026
- New Features:
- Added new HERS Modeler to the Rating Information screen for HERS enabled users
- Rating Field Inspectors reduced from 4 to 3 rows
- Moved the ERI Path Menu to the Rating Information screen and made it a per building setting to avoid confusion when opening a building file on different computers
- Added all 301 standard versions along with their Mandatory Compliance Date (MCD)
- 301-2014 (MCD 1/15/2016)
- 301-2014 + Addendum A (MCD 1/15/2016)
- 301-2014 + Addenda A, E (MCD 2/1/2018)
- 301-2014 + Addenda A, E, G (MCD 3/28/2018)
- 301-2019 (MCD 1/1/2022)
- 301-2019 + Addendum A (MCD 1/1/2022)
- 301-2019 + Addenda A, B (MCD 1/1/2022)
- 301-2019 + Addenda A, B, C (MCD 7/1/2022)
- 301-2019 + Addenda A, B, C, D (MCD 7/1/2022)
- 301-2022 + Addenda A, B (MCD 1/1/2027)
- 301-2022 + Addenda A, B, C (MCD 1/1/2027)
- 301-2022 + Addenda A, B, C, E (MCD 1/1/2027)
- Bug Fixes and Stability Enhancements:
- Fixed an issue where the HERS index hung for pre-2019ABCD versions
- Only request a CO2 index for supported 301 versions
- Restored the 8760 hourly report. See Tools-->Options-->Miscellaneous for the options. Two files are placed in the Temporary Working Directory as:
- RatedHome_8760.csv
- ReferenceHome_8760.csv
- Fixed an issue where 2021 IECC Performance report fails duct leakage on correctly modeled buildings
- Fixed an issue where running ENERGY STAR 3.2 Label in batch causes REM/Rate to crash
- Relax the imposed limits on Infiltration Volume, Conditioned Floor Area,
Finished Floor Area in the Building Information page
2025 Hotfix 30 Late July 2026
- Bug Fixes and Stability Enhancements:
- Resolved an issue where checking for disconnected fuel fired heaters lead to spurious errors for other space heating/conditioning equipment
2025 Hotfix 29 Late July 2026
- Bug Fixes and Stability Enhancements:
- Resolved an issue that caused RESNET credentials to be transmitted incorrectly during building registration
2025 Hotfix 28 Mid July 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue with the shell area computation
2025 Hotfix 27 Mid July 2026
- Bug Fixes and Stability Enhancements:
- Fixed the following issues with Reports
- IECC 2021 label was throwing a "No Reports Selected" error dialog
- ENERGY STAR 3.2 and 3.3 labels were crashing REM/Rate
- Fixed the following issues with Batch Labels
- HERS was sometimes crashing REM/Rate or showing N/A as the ERI number
- ENERGY STAR Multi-Family 1.0 was throwing a "No Reports Selected" error dialog
- Label sequencing and layout issues for the following:
- ENERGY STAR 3.2 and 3.3
- ENERGY STAR Multi-Family 1.2 and 1.3
2025 Hotfix 26 July 2026
- Bug Fixes and Stability Enhancements:
- Fixed several issues that caused REM/Rate to crash
2025 Hotfix 25 July 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue for IECC 2021 where it failed the certificate even though it was passing performance
- Tab order for the ceiling dialog is now in a logical order
- Fixed an issue where disconnected heating equipment causes a non-sensical error in the NREL engine
- Added the ability for a provider to put in a RESNET Registry ID from a downloaded file from RESNET
- Fixed an issue with calculating the height of the foundation wall when it extends above ground, which caused an NREL engine error
- Fixed an issue in the total UA trade-off that incorrectly excludes unconditioned basement components and uses gross foundation wall area
- Fixed an issue where the shell area excludes surfaces with MF buffer, unrated heated, and non-freezing adjacency types
- Added IECC 2021 missing shell UA mandatory check
- Fixed several issues where Energy Star MF 1.1, 1.2, and 1.2 reports were inconsistent between single, batch, and batch label
- Fixed an issue where batch label only generated 8 out 12 labels for Energy Star MF 1.X
2025 Hotfix 24 May 2026
- Bug Fixes and Stability Enhancements:
- When registering with RESNET, REM/Rate no longer outputs HVAC Grading if it has not been done
- Added a Clear button to HVAC Grading screen to remove grading records
- Fixed a HERS Hourly simulation crashes when a building has electric resistance heating (electric air distribution or electric hydronic) and the stored efficiency unit type doesn't match the expected AFUE
- Fixed an issue where a large number of heat pumps causes the HERC report not to print
- Fixed an issue in ENERGY STAR V1.2 MF Home report where it did not work in Batch
- Fixed an issue where exporting to MS Access database throws a field not found error
2025 Hotfix 23 May 2026
- Bug Fixes and Stability Enhancements:
- Fixed an internal error introduced with Hotfix 22 that caused some buildings to display wrong data.
- Please use Hotfix 23 or Hotfix 21 or earlier.
2025 Hotfix 22 April 2026
- New Features:
- The following reports are now available
- Pennsylvania 2021 IECC ERI
- Pennsylvania 2021 IECC UA Compliance
- Pennsylvania 2021 IECC Performance
- Bug Fixes and Stability Enhancements:
- Disabled electric fuel on Fuel-Fired Air Distribution as that is not a valid combination
- Added ASHP conversion in the seasonal engine for electric hydronic distribution, electric air
distribution, and electric baseboard. This affects IECC 2006 - 2021.
- HVAC Grading (formerly HVAC Commissioning)
- Renamed all UI references from "HVAC Commissioning" to "HVAC Grading"
- Fixed a display issue where the heating and cooling equipment were not displayed
- Removed the "Last Altered" date field from the HVAC Grading screen as there is no requirement
for a separate HVAC grading date distinct from the rating date
- Removed the error/warning "HVAC Commissioning date is more than 1 month earlier than Last Field Inspection date"
- Grade III defaults per RESNET 301 are applied automatically by the engine without requiring user entries on the HVAC
Grading screen
2025 Hotfix 21 April 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue with Wisconsin's Focus on Energy Certificate not working
- Enabled HERS ratings for Canadian addresses
2025 Hotfix 20 April 2026
2025 Hotfix 19 April 2026
- Bug Fixes and Stability Enhancements:
- Opening an earlier building file without AG wall orientation will now default the orientation to 'NONE' instead of 'South'
- Fixed an issue with Improvement Analysis where replacing a furnace/AC unit with a heat pump would cause errors in the building
- Fixed an issue where the Building File Report would show N/A and missing library
- Fixed a crash when running the Building File Report along with IECC 2024 or 2025 ECCCNYS
- Replaced interior shading coefficient of 1.0 and now uses 301-2022 defaults of (0.70/0.85)
- Fixed roof absorptance parameter from 0.25 (reflectance) to 0.75 (absorptance) for IECC 2024, IECC 2024 R405, 2025 ECCCNYS
- Enhanced UA report: New detailed Ref vs Design U/F breakdown for IECC 2024 / 2025 ECCCNYS
- Fixed an issue where the 2021 IECC ERI Hourly Report showed a target value of 0 because of a misconfigured climate zone
- Enhanced Mandatory Requirements by adding a checkbox and supporting logic for R408.2.9 Opaque Wall Credit which applies only to 2024 IECC and 2025 ECCCNYS Prescriptive TC compliance path
- Fixed basement/crawlspace thermal boundary assignment for TC compliance so floor vs. foundation wall is correctly selected based on the building's thermal boundary setting
- Corrected page 2 column headers on the 2024 IECC TC / 2025 ECCCNYS TC report
- Fixed a crash when running the Batch Summary Report under all conditions
- Fixed an issue with the computation of the lighting LED percent was wrong resulting in not passing in the IECC 2024 TC Report
- Fixed a crash when running the R405 compliance reports for 2024 IECC and 2025 ECCCNYS where the building only had heating and no A/C
2025 Hotfix 18 March 2026
- Bug Fixes and Stability Enhancements:
- Importing XML without AG wall orientation will now default the orientation to 'NONE' instead of 'South'
- Canadian Zip codes are now accepted for building addresses
- Canadian Package A1 report has been updated from 2017 to 2024
- Fixed an issue where the license PECO report is disabled in the Export Code Compliance Building
- Fixed an issue where Label and Certificate for IECC2024 and NYS2025 did not check performance path correctly
2025 Hotfix 17 March 2026
- New Features:
- The following reports are now available
- IECC 2018 ERI using the hourly engine
- IECC 2021 ERI using the hourly engine
- IECC 2024 Label and Certificate
- ECCNYS 2025 Label and Certificate
- Bug Fixes and Stability Enhancements:
- Fixed an issue where slab depth > 24" below grade were counted in the UA tradeoff analysis
- Updated ENERGY STAR 3.2 report because it showed broken inline analysis (only AG Walls +
Foundation Walls with unclear percentages) instead of proper mandatory requirement checkboxes
- Fixed an issue with the ENERGY STAR 3.2 UA envelope check producing false failures
- Remove slab edge insulation as ENERGY STAR mandatory requirement
- Fixed an issue with the HERS report causing an engine failure if the dishwasher cost / year is $0.01
- Removed spurious "Confirmed - No Registry ID" from non-RESNET reports
- Fixed a perceived GUI hang when running the IECC 2024 and ECCNYS reports
- Removed 105% UA multiplier from ENERGY STAR V3.2 envelope check
- Fixed LED lighting test for IECC 2018 and 2021
- Fixed ACH50 air leakage test for IECC 2018 and 2021
- General cleanup of some of the reports
2025 Hotfix 16 February 2026
- Bug Fixes and Stability Enhancements:
- Fixed a hang when deleting an above grade wall that has windows or doors
- R405 summary now shows the best passing method and correct savings %
- NYS 2025 ERI/performance paths enforce mandatory ACH50 (e.g., 3.0 ACH50 for CZ 4A, not 4.0)
- Fixed a typo with 2009 UA report where the target value of the reference home was 0.480. It should have been 0.350
2025 Hotfix 15 February 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue where the treatment of a wood burning stove caused a crash
- Fixed an issue where IECC ERI 2021 was showing wrong ERI Target for climate zone 4C
- Fixed an issue where R405 Performance simulation crash for buildings with sealed attic rim joists
- Remove R402.5 Max Fenestration U/SHGC mandatory requirement from 2021 IECC ERI
- Fixed a formatting issue with the 2018 ERI Report which made it difficult to read
2025 Hotfix 14 February 2026
- Bug Fixes and Stability Enhancements:
- Fixed a crash running the IECC 2024 ERI report
- Fixed a crash running the IECC 2021 UA Compliance report
- Fixed a R405 simulation error with negative ERV/HRV sensible effectiveness for climate zones 0-5
- Fixed an issue with the IECC 2024 and ECCNYS 2025 mandatory requirements flags not being persisted when saving a building
- Engine now checks for ASRE and ATRE being 0 for heat and energy recovery ventilation
2025 Hotfix 13 January 2026
- Bug Fixes and Stability Enhancements:
- Fixed an issue where the Wisconsin reports were not running
- Fixed an issue in the ERI calculation of Energy Star 3.2 report
- Fixed some calculations in the IECC 2024 and ECCNYS 2025 reports
2025 Hotfix 12 January 2026
- New Features:
- The following reports are now available
- Energy Star 1.2 MF
- Energy Star 1.3 MF
- Energy Star 3.3
- IECC 2024[1] (TC, Performance, ERI Reports)
- ECCNYS 2025[1] (TC, Performance, ERI Reports)
- Known Limitations
- Certificate and Label Reports for IECC 2024 and NCY are not available and will be available soon
- Bug Fixes and Stability Enhancements:
- Fixed Hourly Engine gives error for 0 first hour water usage for an instant water heater
- Fixed an issue where the "Capacity Weight % of Load Served" checkbox isn't working
- Fixed an issue where the EnergyStar 1.1 MF Home Report would sometimes give a Building Modeling error
- The following reports are now licensed individually:
- PPL New Homes Report
- PECO New Homes Rebates Report
- UGI Save Smart New Homes Report
2025 Hotfix 11 December 2025
- Bug Fixes and Stability Enhancements:
- Updated product registration to use REMRate.com.
2025 Hotfix 10 October 2025
- New Features:
- You can now specify the orientation of the Above Ground Walls
- Bug Fixes and Stability Enhancements:
- Fixed some minor issues with UA Tradeoff.
- Fixed a minor mapping issue to the engine.
2025 Hotfix 9 September 2025
- New Features:
- You can now specify the orientation of the Above Ground Walls
- Bug Fixes and Stability Enhancements:
- Fixed issue where some IECC UA reports indicate failure when the building passes.
- Flat Roof had a modeling error which would cause a failure. This was fixed.
- Because of user confusion, hide Orientation on Roofs and let the NREL engine compute the orientation.
- Change Photovoltaics label for Loss Efficiency to Loss Fraction to be more specific
- Revert changes to quick analysis to only show building errors.
- The logic to change climate zones for UA Tradeoff for 2021 and Energy Star 3.2 was fixed
2025 Hotfix 8 September 2025
- New Features:
- You can now specify the orientation of the Above Ground Walls
- Bug Fixes and Stability Enhancements:
- Fixed an issue where if the location for Photovoltaic was blank, it would cause an engine error.
- Added Orientation to AGWalls for more accurate modeling.
- Reused the Lightning Bolt without H in the Analysis Toolbar to simply do the modeling error checks. It is the third button from the left.
- Added in the WeatherData used by the Extras->Utility Bills code.
2025 Hotfix 7 August 2025
- Bug Fixes and Stability Enhancements:
- Energy Star 3.2 was using the wrong target U value for doors. 402.2.4 indicates that they use fenestration.
- The impact is that some buildings with close numbers could be marked as failing. Buildings that passed are correct.
2025 Hotfix 6 August 2025
- Bug Fixes and Stability Enhancements:
- Energy Star 3.1 home report is showing the ERI for the reference home in both target and actual. This has been corrected.
2025 Hotfix 5 August 2025
- Bug Fixes and Stability Enhancements:
- Eliminate an erroneous report of a Reference Home error when registering with RESNET when the building doesn't contain a frame floor.
2025 Hotfix 4 August 2025
- Bug Fixes and Stability Enhancements:
- Updated report template for the Energy Star Home report.
2025 Hotfix 3 August 2025
- New Features:
- Added a new "Developer" role for use within the Provider organization. This can be set or changed using the REM Administrator Web Interface.
- Bug Fixes and Stability Enhancements:
- Fixed a legacy bug that would do improper logic checks on reference homes causing modeling errors showing up in Energy Star MF Reports.
- Removed the region designation from the title bar as a user may be associated with more than one region.
- When DHW using UEF and the Hourly Rate in Gallons is set 0, it causes an error in the hourly engine. Now REM/Rate reports this condition to avert the engine error.
- Fixed a problem with engine mapping for CO2 which would result in a quiet engine failure on 301-2014.
2025 Hotfix 2 Late June 2025
- New Features:
- Auto Update - Checks for and installs updated REM/Rate releases
- Building Interchange File - REM/Rate can now export and import portable building files between releases
- Bug Fixes and Stability Enhancements:
- Fixed an upload crash when mandatory requirements for Energy Star is set to "None"
- Fixed RESNET Registration crash when certain values are used in ducts
- Fixed a bug where the RESNET registry ID comes back empty after registering a building with RESNET
- Fixed an issue in the UA Tradeoff where it erroneously took adiabatic walls in consideration, when it should not have
2025 HotFix 1 Early June 2025
-
Fixed an error where some some buildings with registry ID would be cleared.
2025 May 2025