2026 Florida Building Code: HVAC and mechanical changes
Kyle Lorinos, PE · November 2026 · 9th Edition (2026) FBC, effective December 31, 2026
Florida's 9th Edition codes take effect statewide on December 31, 2026. For HVAC work the changes reach well beyond the Mechanical volume: refrigerant rules, residential ventilation, duct testing, equipment sizing, and several energy code provisions all move at once.
This page summarizes the changes that matter most for HVAC design in Florida, drawn from the Florida Building Commission's official Analysis of Changes for the Mechanical, Residential, and Energy Conservation volumes. It also covers the energy code envelope changes, including windows, skylights, insulation, and air leakage, that architects will need to show on their drawings. It is organized by code volume, with a short note on what each change likely means in practice.
Which edition applies to my project?
Permit applications submitted on or after December 31, 2026 must generally comply with the 9th Edition. Projects permitted under the 8th Edition (2023) typically remain under that edition for the life of the permit. Some jurisdictions, including Miami-Dade, have published specific cutoff times for online submittals, so confirm with your building department.
The top changes for HVAC designers
A2L refrigerants are fully integrated. High-probability comfort cooling systems must use Group A1 or A2L refrigerants, with new listing, piping, testing, and machinery room requirements aligned with ASHRAE 15, ASHRAE 15.2, and UL 60335-2-40.
Condensate drains in unconditioned space need R-3 insulation. This now appears in both the Mechanical code (307.2.2) and the Residential code (M1411.9.2).
Residential cooling equipment sizing has three compliance options. FBCEC R403.7.1.1 adds a sensible-capacity path and a supplementary dehumidifier path alongside the Manual S total capacity path.
Residential mechanical ventilation must be flow tested. New FBCEC R403.6.3 requires verification of ventilation airflow, with a new test report form.
Duct leakage testing applies to performance-path homes too. The R405 exception to duct testing has been removed.
Multifamily outdoor air rates go up. The floor area factor in Equation 4-9 increases from 0.01 to 0.03 cfm/ft² of conditioned floor area, and the section now covers R-2, R-3, and R-4 occupancies of any height.
Common exhaust shafts in multifamily are restricted. Exhaust from separate dwelling or sleeping units may not share a duct or shaft unless it is maintained at negative pressure.
Commercial dehumidification limits. New FBCEC C403.8.1 generally prohibits mechanical cooling from driving a zone below a 55 °F dew point or 60% RH, whichever is lower.
PVC condensate in residential air handler closets used as plenums. A new exception allows it in R-2 and R-3 dwelling units when specific conditions are met.
Rooftop equipment access ladders follow OSHA, and a 30-inch-deep landing is now required on the exit side of roof hatches.
Key changes for architects
Most of the HVAC changes stay inside the mechanical drawings, but the energy code changes land squarely on the architectural set: window schedules, wall and roof sections, ceiling heights, and door details. If your project will be permitted on or after December 31, 2026, these are the items worth raising with your mechanical engineer during design development.
Residential projects
Energy code compliance. The margins for passing with performance method calculations will be much tighter, with the target dropping from 95% to 85% of the reference design (FBCEC R405.3). It will be more difficult to use high-performing HVAC equipment to compensate for lower rated glass. Meeting the prescriptive values for wall and roof/ceiling insulation, as well as glazing U-factor and SHGC, is going to become the primary path for energy code compliance, along with the new additional efficiency credits (FBCEC R407).
Windows and skylights. Even under the performance method, the area-weighted SHGC limit drops from 0.50 to 0.40 unless overhangs average 4 feet or more (FBCEC R405.5.3.4). Skylights tighten to a maximum U-factor of 0.60 and SHGC of 0.28. Show the required U-factor and SHGC on the window schedule, based on NFRC-certified ratings. See the envelope section for details.
Insulation. The code now includes continuous insulation options for frame walls and floors, and spray foam unvented attics have a defined compliance path at a minimum of R-20 (FBCEC R402.1, Exception 3). Attic hatches and pull-down stairs also need durable gasketing and insulation.
Duct location. There are new credits for keeping ductwork inside conditioned space (FBCEC R407). A conditioned attic, interior chases, or dropped soffits below insulated ceilings may make compliance easier, so it's worth discussing where ceiling heights allow for it.
Laundry closets. Closet dryer installations will need makeup air, typically at least 100 in² of permanent opening (FBCR M1502.6.1), so louvered or undercut doors will need to be shown.
Mechanical equipment space. New equipment uses A2L refrigerants, and some indoor units carry room-size or ventilation requirements in their listing. Reserve air handler and plenum space early, and confirm closet sizes with your engineer once equipment is selected.
Commercial and multifamily projects
Window performance. Window U-factors tighten in both Florida climate zones, and SHGC tightens in Climate Zone 1, which includes Palm Beach, Broward, Miami-Dade, Monroe, Collier, Lee, and Hendry Counties (FBCEC Table C402.4). Ratings must carry NFRC-certified labels. The values are listed in the envelope section.
Insulation details. Insulation laid on suspended ceiling tiles no longer counts toward the roof R-value, cavity insulation cannot be used to meet a continuous insulation requirement, and R-values cannot be averaged across an assembly except for tapered roof insulation.
Air leakage testing. The whole-building air leakage limit tightens from 0.40 to 0.35 cfm/ft², with third-party testing, and multifamily and hotel projects add sampled dwelling unit testing. Air barrier continuity needs to be detailed with testing in mind.
Multifamily outdoor air. The dwelling unit ventilation formula now uses 0.03 cfm/ft² of conditioned floor area instead of 0.01 and applies to R-2 occupancies of any height (FBCM 403.3.2.1). Expect larger ERVs or dedicated outdoor air units, and possibly larger wall louvers, mechanical closets, or shaft space.
Shared exhaust shafts. Exhaust from separate dwelling or sleeping units may only share a duct or shaft if it is kept at negative pressure (FBCM 501.6). This typically means a continuously running roof exhaust fan at each riser, or individual unit exhaust terminations that affect facades and roof penetrations.
Roof hatches. A clear landing at least 30 inches deep and the full width of the hatch is required on the exit side, and permanent ladders now follow OSHA dimensions (FBCM 306.5).
Machinery rooms. Refrigeration machinery rooms over 1,000 ft² need at least two exits or exit access doorways (FBCM 1105.10). This mainly affects chiller plants.
Commercial kitchens. Appliances with draft hoods or atmospheric burners, such as some gas water heaters, may not be in the same room as a kitchen hood unless they are in a sealed, self-closing enclosure (FBCM 507.1.3).
Vestibule air curtains. Where air curtains are used in place of vestibules, they must meet minimum velocity testing and be functionally tested (FBCEC C402.5.7).
Energy code, building envelope (windows, insulation, and air leakage)
These provisions sit in the FBC, Energy Conservation and mostly land on the architectural drawings: window schedules, wall and roof sections, and air barrier details. Where the Florida Building Commission's published analysis gives specific values, they are listed below. Where it notes a change without publishing the values, confirm the numbers in the adopted tables before specifying.
Residential envelope
Section
What changed
Design impact
R405.5.3.4 Key
For the performance method, the maximum area-weighted fenestration SHGC of the proposed design drops from 0.50 to 0.40. The exception for average overhang depths of 4.0 feet or more is retained.
Most Florida homes comply through the performance method, so this is likely the window change with the broadest reach. Specify SHGC on the window schedule, or use deep overhangs where the design allows.
Table R402.1.2 Key
Skylight maximum U-factor drops from 0.75 to 0.60 in Climate Zone 1 and from 0.65 to 0.60 in Climate Zone 2. A new skylight SHGC column sets a 0.28 maximum (previously 0.30).
Confirm skylight and tubular daylighting product selections against the new limits.
Table R402.1.2
Vertical fenestration column retitled and footnotes revised. The Commission's analysis shows no numeric change to vertical window U-factor or SHGC for Climate Zones 1 and 2.
Prescriptive window values for vertical glazing appear to carry over from the 2023 code.
Table R402.1.2
New cavity-plus-continuous and continuous-only insulation options for wood frame walls and floors. A new heated slab column is added, and the mass wall footnote is clarified.
More ways to meet wall and floor requirements, including exterior rigid insulation.
R402.1, Exc. 3
Unvented attics and enclosed rafter assemblies with at least R-20 air-impermeable insulation may comply when airtightness, ventilation, rafter insulation, and HVAC equipment and duct location requirements are met (per HB 267).
A defined path for spray foam roof decks, which also helps keep ducts in conditioned space.
Table R402.4.1.1
Attic access openings, drop-down stairs, and knee-wall doors must be sealed with durable gasketing and insulated. Eave baffles must meet R402.2.3.
Detail attic hatches and pull-down stairs accordingly.
R303.1.3
Fenestration U-factor, SHGC, and VT must be labeled and certified by manufacturers meeting new authorization requirements. Tubular daylighting devices need VT measured per NFRC 203.
Window schedules and submittals should reference NFRC-certified ratings.
R401.2, R407
The prescriptive path now requires additional efficiency credits: 10 credits from at least two measures, plus 5 more for dwellings over 5,000 ft².
Decide early which credits the project will use. Some are envelope-related, others are HVAC.
R405.3
The performance path target tightens from 95% to 85% of the Standard Reference Design.
Envelope choices such as SHGC, insulation, and air tightness carry more weight in passing.
Commercial envelope
Section
What changed
Design impact
Table C402.4 Key
Vertical fenestration U-factors tighten in Climate Zones 1 and 2. SHGC tightens in Climate Zone 1 only, with separate limits for north-facing glazing. Skylight U-factor and SHGC tighten in Climate Zone 1. See the values below.
Re-check storefront, curtain wall, and entrance door selections, and show the required values on the window schedule.
C303.1.3
Fenestration ratings must include SHGC and VT, with labels from an NFRC-licensed independent certification agency.
Reference NFRC-certified ratings in specifications and submittals.
C402.5.1.2 Key
Whole-building air leakage limit tightens from 0.40 to 0.35 cfm/ft² at 0.3 in. w.g. An alternative of 0.27 cfm/ft² at 0.2 in. w.g. is available for Group I-1 and R-1 buildings tested by an approved third party.
Air barrier continuity needs to be detailed at transitions, penetrations, and fenestration.
C402.5.1.2.3, C402.5.1.2.4
Third-party whole-building testing with a report to the code official and owner. New dwelling and sleeping unit enclosure testing, with sampling for buildings of 8 or more units.
Multifamily and hotel projects should plan for unit testing in the schedule and specifications.
C402.1.3.1, C402.1.3.2
Cavity and continuous insulation R-values are summed, but cavity insulation cannot satisfy a continuous insulation requirement. Area-weighted averaging of R-values is not permitted, except for tapered above-deck roof insulation.
Wall and roof sections need to meet the requirement at every location, not on average.
C402.2.2.1
Insulation installed on suspended ceilings with removable tiles does not count toward the roof R-value or assembly U-factor.
Roof insulation must be in the roof assembly. This affects many tenant buildout and retail details.
Tables C402.1.3, C402.1.4
Non-swinging opaque doors move from R-value to U-factor requirements. Swinging door U-factors and heated slab F-factor are updated.
Overhead and coiling doors are specified by U-factor.
C402.5.7
Air curtains used in place of vestibules must deliver at least 6.56 ft/s at 6 inches above the floor and be function tested.
Specify tested air curtain products and include them in commissioning.
Commercial fenestration limits, Climate Zones 1 and 2 (Table C402.4)
Maximum values in the 9th Edition. Values in bold changed from the 2023 code. In Florida, Climate Zone 1A covers Broward, Collier, Hendry, Lee, Miami-Dade, Monroe, and Palm Beach Counties, and the rest of the state is Climate Zone 2A (FBCEC Table R301.1). PF is the projection factor of overhangs. "North" means glazing oriented within 45 degrees of true north.
Vertical fenestration
Climate Zone 1
Climate Zone 2
U-factor, fixed
0.50
0.45
U-factor, operable
0.62
0.60
U-factor, entrance doors
0.83
0.77
SHGC, PF < 0.2 (other / north)
0.23 / 0.21
0.25 / 0.33
SHGC, 0.2 ≤ PF < 0.5 (other / north)
0.28 / 0.25
0.30 / 0.37
SHGC, PF ≥ 0.5 (other / north)
0.37 / 0.34
0.40 / 0.40
Skylight U-factor
0.70
0.65
Skylight SHGC
0.30
0.35
FBC, Mechanical (commercial and multifamily)
The 9th Edition FBC, Mechanical uses the 2023 Florida code as its base and draws updates from the 2024 International Mechanical Code. Not every 2024 IMC change was adopted, so national summaries of the IMC may not match Florida exactly.
Refrigeration and A2L refrigerants (Chapter 11)
Section
What changed
Design impact
1101.2
New Table 1101.2 identifies the listing standard for each type of factory-built equipment.
Easier to confirm the correct listing on equipment schedules and submittals.
1101.2.1 Key
High-probability equipment using Group A2L, A2, A3, or B1 refrigerant must comply with UL 484, UL/CSA 60335-2-40, or UL/CSA 60335-2-89.
Verify the listing on new split systems, packaged units, and VRF. Most new A2L equipment should already carry the 60335-2-40 listing.
1101.8, 1102.2.1
Changing or mixing refrigerants across safety classes now follows ASHRAE 15.
Retrofits that change refrigerant type deserve a closer look before specifying.
1104.3.1 Key
High-probability direct systems for human comfort must use Group A1 or A2L refrigerants. Table 1104.3.2 is deleted and folded into the text.
Charge limits and mitigation (leak detection, ventilation) come from the equipment listing and ASHRAE 15.
Table 1103.1
Updated with refrigerants newly added to ASHRAE 34.
Includes current A2L refrigerants such as R-454B and R-32.
1105.6.1.1
Machinery room exhaust intakes must be located where leaked refrigerant would concentrate, based on its density relative to air.
Most refrigerants are heavier than air, which usually points to low exhaust pickups.
1105.10
Machinery rooms over 1,000 ft² need at least two exits or exit access doorways, with travel distance and hardware requirements.
Coordinate with the architect early on chiller plant layouts.
1106.5 to 1106.5.3
New A2L and B2L machinery room rules: no open flames or hot surfaces over 1,290 °F, refrigerant detectors tied to alarm and ventilation (Table 1106.5.2 response times), and ASHRAE 15 mechanical ventilation.
Applies to central plants using A2L refrigerants. Coordinate detector and fan controls with the BMS.
1107 to 1110
Refrigerant piping reorganized into piping materials, joints and connections, installation, and testing. Field testing now requires both a pressure test and a vacuum test, using nitrogen, helium, argon, or nitrogen with a tracer gas.
Update piping and testing specification language and plan notes.
General regulations (Chapter 3)
Section
What changed
Design impact
307.2.2 Key
Condensate drain piping from cooling coils and evaporators must be insulated to at least R-3 when located in unconditioned space within a building.
Add to plan notes and specifications. Attic and ceiling plenum condensate runs are the common case in Florida.
306.5
Permanent ladder dimensions now follow OSHA. A clear landing at least 30 inches deep, the full width of the hatch, is required on the exit side of roof hatches.
Confirm roof access details on projects with rooftop units.
301.16
New exception: flood-damaged exterior equipment being replaced (outside a substantial improvement) may be elevated to the first floor height or 4 feet above grade, whichever is higher.
Gives a practical path for condensing unit replacements after flood damage.
302.3, 302.5
Cutting, notching, and boring of framing now defers to the Building code (wood) and AISI S240/S220 (cold-formed steel).
Reference the new sections in duct and pipe routing notes.
306.1
"Be accessible" changed to "provide access."
Editorial, but it may show up in plan review comments.
Ventilation (Chapter 4)
Section
What changed
Design impact
403.3.2 Key
Dwelling unit ventilation provisions now apply to all Group R-2, R-3, and R-4 occupancies, not only buildings three stories or less.
Mid-rise and high-rise multifamily units now use this path rather than Table 403.3.1.1.
403.3.2.1 Key
In Equation 4-9, the floor area factor rises from 0.01 to 0.03, and the area is now conditioned floor area.
Expect noticeably higher dwelling unit outdoor air rates, especially for larger units. Revisit ERV and dehumidification sizing.
Table 403.3.2.3
Minimum continuous local exhaust rates increase from 25 cfm to 50 cfm.
Update exhaust fan schedules and standard notes for multifamily and hotel units.
Table 403.3.1.1
New occupancy categories added, including outpatient healthcare, break rooms, coffee stations, central laundry, animal facilities, and telephone closets.
Fewer judgment calls on unlisted space types in ventilation schedules.
401.4
Combination intake/exhaust termination fittings no longer need to be "approved," and installation follows the fan manufacturer's instructions.
Minor clarification.
Exhaust systems and kitchen hoods (Chapter 5)
Section
What changed
Design impact
501.6 Key
Exhaust fans serving separate dwelling or sleeping units may not connect to a common duct or shaft unless it is kept at negative pressure.
Common bath exhaust risers in condos and hotels likely need a continuously operating roof exhaust fan.
501.3.1
The 3-foot separation from operable openings no longer applies where the exhaust outlet is at least 1 foot above a gravity air intake.
Some relief on tight exterior wall terminations.
504.10
Commercial dryer transition ducts must be listed and labeled to UL 2158A.
Add to specifications for laundry rooms.
506.3
"Grease duct" is now a defined term, and grease duct provisions are reworded throughout. An alternative water spray test is added, and the light test now allows LED lamps of 1,600 lumens or more.
Mostly terminology, with more flexibility in testing.
507
Kitchen hood section reorganized. New exceptions for certain ovens, electric cooking appliances, and electric dishwashers. A Type I hood may be used where a Type II hood is required.
Section numbers have moved, so update references in notes and specs.
507.1.3
Appliances with draft hoods or atmospheric burners may not share a room with a Type I or Type II hood unless installed in a sealed enclosure with outdoor or Chapter 7 combustion air.
Watch for atmospheric water heaters located in commercial kitchens.
508.1.1
Clarifies that the 10 °F makeup air differential is measured against the kitchen thermostat setpoint, and that makeup air loads go either to the kitchen HVAC or a dedicated conditioning system.
Helpful clarity for restaurant load calculations.
Duct systems and plenums (Chapter 6)
Section
What changed
Design impact
602
Plenum section reorganized for clarity on what materials may be located in a plenum.
Section numbers have moved.
602.3 Key
New exception allows PVC condensate piping in air handler closets used as plenums in R-2 and R-3 dwelling units, when all listed conditions are met.
Resolves a common inspection conflict in Florida apartments and condos.
604.3
New exception from flame spread and smoke-developed limits for duct coverings applied outside ducts and not located in plenums.
More product flexibility for exterior duct wrap outside plenums.
Appliances, hydronics, and new appendices
Section
What changed
Design impact
912
Now covers permanently installed electric space heaters, which must be listed to UL 2021.
Applies to wall and ceiling heaters.
931
New: steam bath equipment must be listed to UL 499.
Relevant to high-end residential and spa projects.
1205.1
Access is required to all full-open valves and shutoff valves.
Coordinate access panels in hydronic and chilled water work.
1203.20, 1203.21
New joint requirements for stainless steel pipe and tubing. Polybutylene removed.
Specification updates.
1209.6
New radiant tubing rules: maximum circuit lengths, circuit tags at manifolds, and drawings provided to the owner.
Mostly relevant to radiant cooling projects in Florida.
Appendix C
Optional: Group A, B, E, and I systems sized for MERV 13 filter pressure drop.
Only applies if a jurisdiction adopts it.
Appendix D
Optional: CO2 sensors, thresholds, and notifications in Group A, B, E, and I occupancies.
Only applies if a jurisdiction adopts it.
FBC, Residential (mechanical chapters)
One- and two-family dwellings and townhouses follow the FBC, Residential. The mechanical chapters picked up several practical changes from the 2024 IRC.
Section
What changed
Design impact
M1411.2 to M1411.7 Key
New A2L refrigerant provisions consistent with ASHRAE 15.2: system listing, installation, field-installed accessories, signage, refrigerant charge, and A2L piping testing.
Applies to essentially every new residential split system and heat pump going forward.
M1411.9.2 Key
Condensate drain piping in unconditioned space must be insulated to at least R-3.
Attic air handlers in Florida homes will commonly trigger this.
M1502.6
Dryers exhausting more than 200 cfm need makeup air. Closet dryers need makeup air per the manufacturer, or at least 100 in² of permanent opening.
Check laundry closet louvers and door undercuts on plans.
M1503.3, M1507.4
Variable and multi-speed exhaust fans are permitted if one setting meets the minimum rate.
More product flexibility for range hoods and bath fans.
M1503.4.1
Clarifies that the kitchen makeup air location rule applies to makeup air ducted from outdoors.
Clarification.
M1602.2
Item 4 is revised to remove the prohibition on taking return air from a bathroom.
A notable shift. Many designers will likely still avoid bathroom returns as good practice.
M1308.2.1, M1308.2.2
Setback for piping in bored holes without a shield plate reduced from 1-1/2 to 1-1/4 inches.
Minor framing relief.
M1402.1, M1404.1, M1412.1
Clarifies that electric furnaces, refrigeration cooling equipment, and absorption equipment must be listed and labeled.
Clarification.
M2006.1
Pool and spa heat pump heaters must be listed to UL 1995 or UL/CSA/ANCE 60335-2-40.
Common in Florida residential work.
R322.1.6
Flood-damaged exterior equipment replacements (outside substantial improvement) are elevated to the first floor height or 4 feet above grade, whichever is higher.
Applies to condensing units and pool equipment in flood zones.
Energy code, residential HVAC provisions
Several of the most consequential residential HVAC changes sit in the FBC, Energy Conservation rather than the mechanical chapters.
Section
What changed
Design impact
R403.7.1.1 Key
Cooling equipment sizing now offers three options: (A) Manual S total capacity limits by equipment staging, (B) sensible capacity not more than 1.20 times the sensible load with latent capacity covering the latent load, or (C) a permanently installed supplementary dehumidifier covering the latent load, with a notice on the air handler.
Options B and C give real flexibility for low-sensible-load Florida homes. Load calculation reports should clearly identify which option is used.
R403.7.1
The manufacturer and model number of any supplementary unit must be documented.
Add to equipment schedules.
R403.6.3, R403.6.4 Key
New mechanical ventilation flow rate testing and verification, with limited exceptions and unit sampling for buildings with eight or more units.
Ventilation airflow must be measured at closeout. A new test report form appears in Appendix RD.
R403.6.5
New control options for intermittent bathroom and toilet room exhaust.
Specify a compliant control (timer, occupancy, humidity, and similar).
R403.3.3, R405.2.3 Key
The duct testing exception for the performance path is removed.
Duct leakage testing applies regardless of compliance path.
R405.3
Performance path target tightened from 95% to 85% of the Standard Reference Design.
Performance-path homes need more efficiency to pass. HVAC efficiency and duct location carry more weight.
R407
New additional efficiency credits for the prescriptive path, including higher-efficiency HVAC, ductwork in conditioned space (at least 80%), ductless or hydronic distribution, and demand-responsive thermostats.
Ducts in conditioned space becomes a practical credit to plan for early.
R402.1, Exc. 3
Unvented attics with at least R-20 air-impermeable insulation can comply when airtightness, ventilation, rafter insulation, and HVAC and duct location requirements are met (per HB 267).
Relevant to spray foam attic designs with attic air handlers.
R403.1.2
Smart thermostats added, with clarified setback capability.
Thermostat specifications.
R403.13
Dehumidifier efficiency now tied to specified test methods and an efficiency standard.
Verify listed efficiency on whole-house dehumidifiers.
Energy code, commercial HVAC provisions
Section
What changed
Design impact
C403.8 Key
New humidity controls. Mechanical cooling may not drive humidity below the lower of a 55 °F dew point or 60% RH in the coldest zone served, and humidification and dehumidification may not run at the same time. Exceptions apply to spaces with specific humidity requirements.
Review reheat and hot gas reheat sequences, and document exceptions for spaces like labs, healthcare, and archives.
C403.2.9.1.3
Outside air ducts running through conditioned space in Climate Zone 1A must be insulated to prevent condensation.
Directly relevant to all of South Florida.
C403.2.3(1)
Air-cooled single-package units under 65 kBtu/h rise to 13.8 SEER2 (from 13.4).
Check small packaged unit schedules.
C403.2.3(11), (12)
VRF efficiency tables revised across capacity bands.
Confirm VRF schedule values against the new tables.
C403.2.4.1.2
Separate heating and cooling setpoints, initially configured for at least a 5 °F deadband.
Sequences of operation and thermostat specifications.
C403.9
New occupied-standby controls for specified space types, including resetting zone outdoor air to zero in standby.
Requires occupancy sensors tied to HVAC in applicable spaces.
C403.2.6.1
Demand control ventilation restructured into single-zone and multi-zone pathways.
Re-check DCV applicability thresholds.
C403.2.8
Demand control kitchen ventilation required where total Type I hood exhaust exceeds 5,000 cfm.
Larger restaurants and commercial kitchens.
C403.2.12.5.4, C403.2.12.8
New intermittent bathroom exhaust control rules and minimum efficiency for air circulating fans of 200 W and above.
Fan schedule and control specifications.
C406
New credit-based pathway for buildings over 2,000 ft², with HVAC measures for higher-efficiency equipment, residential setback, DOAS with energy recovery, and fault detection.
Plan which credits the project will pursue during design, not at permit.
C408.2.2.1
Adds TABB and the SMACNA TAB procedural guide as balancing references.
Update TAB specification language.
C409
New optional HVAC total system performance ratio (TSPR) compliance method.
An alternative path for qualifying systems. Requires energy modeling.
What to do before December 31
Decide the permit path on active projects. If a project is nearly ready, submitting before the cutoff may keep it under the 8th Edition. If it will not be ready, it is likely better to design to the 9th Edition now.
Update standard notes and specifications. Condensate insulation, A2L refrigerant piping and testing, refrigerant listings, and TAB references are the common ones.
Revisit multifamily ventilation. Higher dwelling unit outdoor air rates and the common shaft restriction can change ERV, dehumidification, and riser design.
Document residential equipment sizing clearly. State which R403.7.1.1 option the equipment selection uses.
Plan for ventilation testing at closeout on residential projects.
Check local amendments. Counties and municipalities, including those in the High-Velocity Hurricane Zone, may have additional requirements.
Use this page as a guide, not as the code.
This summary is based on the Florida Building Commission's Analysis of Changes, which itself notes that it does not replace or interpret the code. Always confirm requirements in the adopted code text and with the authority having jurisdiction.
Designing a project under the 2026 code?
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