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🏛️ Connecticut⚡ RRES Solar Adj. 8× Higher in 2026

Connecticut
Solar Permit Plans.
NEC 2020. RRES Netting or Buy-All.
169 Municipal AHJs.

Connecticut's RRES program replaced net metering in 2022 and gives new customers two tracks — Netting Tariff (retail-rate credits, roll over indefinitely) or Buy-All Tariff (fixed-rate for 20 years). The fine print that matters most in 2026: the Solar Energy Adjustment charged to new RRES Netting enrollees jumped to $0.0402/kWh — eight times the 2025 rate — and it's locked for the entire 20-year enrollment term. Every Connecticut solar proposal needs to account for this math before presenting payback figures.

NEC 2020 — 2022 CSBC current 2026 CSBC (NEC 2023) delayed RRES Netting or Buy-All — 20-year term Solar Energy Adj: $0.0402/kWh (2026) 169 Municipal AHJs
Order CT Plan Set →See the RRES Details ↓
NEC 20202022 CSBC — effective Oct 1, 2022
$0.0402/kWh2026 Solar Energy Adjustment
$0.3289/kWhBuy-All fixed rate — 2026 enrollees
169 MunicipalitiesEach its own AHJ and permit process
NEC 20202022 CSBC — current
2021 IBC + IRC2022 CSBC structural
RRES Netting / Buy-All20-year term — locked at enrollment
Eversource + UITwo IOUs — same RRES terms
169 MunicipalitiesAll AHJs covered
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AHJ-ReadyPer municipal building department
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24–48 HrsTypical residential turnaround
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Free RevisionsFor AHJ-requested corrections
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150+ PartnersSolar installers, EPCs & roofers
Connecticut Solar Permits — 2026

New Code Delayed. New Solar Adjustment in Force. 169 Municipalities, Each Its Own AHJ.

Permit Design builds Connecticut solar permit plan sets for solar installers, EPCs, and roofing companies across all 169 municipalities. The current Connecticut electrical code is NEC 2020 under the 2022 Connecticut State Building Code (2022 CSBC, based on 2021 I-Codes, effective October 1, 2022). The 2026 CSBC — which adopts NEC 2023 and the 2024 IBC — was drafted and opened for public comment in 2025 but as of June 2026 awaits Legislative Regulation Review Committee approval from the Connecticut General Assembly, making NEC 2020 the current standard. Permit Design tracks the Office of the State Building Inspector for the official 2026 CSBC effective date.

Connecticut's solar program structure is the RRES (Residential Renewable Energy Solutions) tariff, which replaced net metering in 2022 after the prior RSIP program met its 350 MW deployment goal. RRES offers two tracks: the Netting Tariff (solar first, excess credits at retail rate, indefinite rollover) or the Buy-All Tariff (all production sold at a fixed rate for 20 years). The 2026 Solar Energy Adjustment of $0.0402/kWh — applied to all solar production for new Netting Tariff enrollees, not just exports — represents an 8× increase from the 2025 rate of $0.005/kWh and is locked for the full 20-year enrollment term. Connecticut's 169 municipalities each operate as independent AHJs with their own permit applications, fees, and inspectors.

Last updated: June 2026 · 2022 CSBC NEC 2020 status, RRES 2026 Solar Energy Adjustment, and 2026 CSBC delay confirmed as of June 2026.

Connecticut RRES Program

Two Tracks. Twenty Years. The Enrollment-Year Rate Locks Forever.

Connecticut's RRES program is administered by Eversource and United Illuminating under PURA regulation. Rates are reset annually for new enrollees. What matters most: whatever Solar Energy Adjustment applies when a customer enrolls is locked for 20 years.

2026 Solar Energy Adjustment: $0.0402/kWh — 8× the 2025 rate. New RRES Netting Tariff customers enrolling in 2026 pay $0.0402 per kWh on all solar production — not just on exported energy, but on every kWh the system generates. For an 11 kW system producing 12,925 kWh per year, this is approximately $520 annually deducted from solar savings, and it is locked for the full 20-year enrollment term. A customer who enrolled in 2025 pays $0.005/kWh for the same 20 years. This difference alone can exceed $10,000 over the term on a typical Connecticut system. Every 2026 Connecticut solar proposal should include this cost in the payback model.
RRES Netting Tariff — Most Popular
Solar First, Retail Credits, Indefinite Rollover
The Netting Tariff works like enhanced net metering: your solar system powers your home first, and any excess generation is credited at the retail rate on your bill. Credits roll over indefinitely — there's no annual true-up that pays excess at a reduced rate. The Solar Energy Adjustment ($0.0402/kWh in 2026) is charged against all production and is netted from your credits. With Eversource rates near $0.29/kWh and UI near $0.28/kWh, the net value of self-consumed solar is still strong — but the $0.0402 adjustment materially reduces the effective credit for exported production compared to the prior RSIP net metering framework.
RRES Buy-All Tariff — PPA-Friendly
All Production Sold at Fixed Rate for 20 Years
Under the Buy-All Tariff, all solar production is sold to the utility at a fixed rate — approximately $0.3289/kWh for 2026 enrollees — and the customer purchases all electricity at the standard retail rate. The customer receives a separate production payment, not a bill credit. This structure simplifies the financial model for third-party-owned systems (PPAs and solar leases), since there's a fixed revenue stream that doesn't depend on the household's load profile. The fixed rate is set annually and locked for 20 years at enrollment.
RRES interconnection: up to 25 kW is Level 1, 4–8 week timeline. Systems up to 25 kW use the simplified Level 1 interconnection process at both Eversource and United Illuminating, with a typical timeline of 4 to 8 weeks from application to permission to operate. Systems above 25 kW move to Level 2 and require engineering review. Connecticut does not have a statewide standardized permit application — each of the 169 municipalities sets its own documentation requirements, though the 2016 Connecticut Standardized Solar PV Permit Application Supplement was created to reduce variation and is referenced by many towns.
Connecticut Code Structure

NEC 2020 Current · 2026 CSBC (NEC 2023) Delayed · 2021 IBC + IRC In Force

Connecticut is in the middle of a code transition that hasn't completed. The 2022 CSBC governs permits today. The 2026 CSBC is ready but stuck in the legislature.

Current — Electrical
NEC 2020 (2022 CSBC)
✓ Effective October 1, 2022
✓ §690.12: single RSD device
✓ UL 3741 PVHCS path recognized
✓ §690.12(D) labeling format
Current — Structural
2021 IBC + 2021 IRC
✓ Both effective October 1, 2022
✓ CT amendments apply
✓ ASCE 7 wind + snow per municipality
✓ Coastal towns: higher wind exposure
Pending — 2026 CSBC
NEC 2023 + 2024 IBC — Delayed
⚠ Awaiting LRRC approval
⚠ Was expected July 1, 2026
→ Check OSBI for effective date
→ We update plan sets when enacted
Connecticut's ASCE 7 snow loads are meaningful in the northwest. Litchfield County towns including Torrington, Norfolk, and Canaan carry significantly higher ground snow loads than the coastal Sound towns in Fairfield and New Haven counties. Connecticut's coastal Fairfield County communities face elevated wind exposure categories due to Long Island Sound exposure. Both factors are applied per the specific municipality rather than statewide average — a meaningful structural difference between a Stamford rooftop and a Norfolk installation.
Connecticut Utilities

Two IOUs, Same RRES Terms, Different Service Areas

Connecticut has two investor-owned electric distribution utilities, both administering the RRES program under identical PURA terms. Your utility is determined by address and cannot be changed.

Eversource Energy
~$0.29/kWh — Most of Connecticut
Eversource serves the majority of Connecticut including Hartford, Norwalk, Waterbury, Danbury, New Britain, Meriden, and most of the north, east, and central portions of the state. RRES Netting Tariff customers receive retail-rate credits against their Eversource bill. Level 1 interconnection (≤25 kW) follows the standard 4–8 week timeline. Eversource's service territory boundaries are sometimes surprising in southwestern CT — some towns that appear to be in UI territory are partially served by Eversource.
United Illuminating (Avangrid)
~$0.28/kWh — New Haven + Bridgeport Area
United Illuminating, a subsidiary of Avangrid (Iberdrola), serves New Haven, Bridgeport, Derby, Shelton, Ansonia, and surrounding shoreline communities in New Haven and Fairfield counties. UI customers use the same RRES tariff options and Solar Energy Adjustment rates as Eversource customers. The Level 1 interconnection process is identical. UI's service area is geographically compact — installers working the New Haven and Bridgeport corridor will work within UI territory consistently.
Connecticut Green Bank programs work with both utilities. The Smart-E Loan program offers 4.49% to 6.99% APR financing for solar and energy efficiency through the Connecticut Green Bank, available to Eversource and UI customers alike. The Energy Storage Solutions (ESS) battery rebate — up to $7,500 for qualifying battery systems — is also available statewide regardless of utility. With the federal Section 25D credit expired, the ESS rebate and Green Bank financing are currently the most significant financial levers for Connecticut homeowners in 2026.
What's Included

Connecticut Solar Permit Plan Set Contents

Every Connecticut plan set references NEC 2020 under the 2022 CSBC, the 2021 IBC or IRC with Connecticut amendments, ASCE 7 loads for the specific municipality, and RRES interconnection documentation for the confirmed utility and tariff track.

Sheet 01
Cover Sheet
NEC 2020 citation under the 2022 Connecticut State Building Code (effective October 1, 2022) with Connecticut amendments noted. 2021 IRC (residential) or 2021 IBC (commercial) structural reference. Utility confirmed — Eversource or United Illuminating. RRES tariff track noted — Netting or Buy-All. Municipality and AHJ identified.
Sheet 02
Site Plan
Scaled site drawing locating property boundaries, the Eversource or UI meter and service point, fire department access lanes, and the conductor run from array through inverter to panel. ASCE 7 lookup values pulled for the specific municipality, since Litchfield County interior towns carry meaningfully higher ground snow than the Sound-facing shoreline, where wind exposure dominates the design instead.
Sheet 03
Roof Layout
Array layout drawing covering module count, orientation, roof pitch, and attachment spacing tied to 2021 IRC framing requirements. Setback pathways shown per the local fire marshal adopted standard, since Connecticut towns split between OSFM and IFC setback conventions and we confirm which applies before drafting. Ground-to-roof snow conversion calculated per the municipality ASCE 7 figures.
Sheet 04
Single-Line Diagram
Article 690 single-line schematic built to NEC 2020, showing the source circuits, combiner, inverter, and rapid shutdown device per §690.12. RRES metering configuration drawn for the confirmed track — bidirectional Netting meter or Buy-All production meter — and the diagram flags whether the system falls under the 25 kW Level 1 threshold or requires Level 2 review.
Sheet 05
Structural Calculations
Connecticut-licensed PE stamp covering roof framing or racking adequacy. 2021 IRC for residential; 2021 IBC for commercial. ASCE 7 ground snow and wind values pulled per municipality — northwest Connecticut (Litchfield County) carries design snow loads well above coastal Connecticut. Results reviewed against the 2022 CSBC structural amendments specific to Connecticut.
Sheet 06
Rapid Shutdown
Compliance sheet for §690.12 — boundary marked at one foot from the array edge, single shutdown switch identified, current labeling format applied. PVHCS alternate path noted if the design uses it. Since the 2026 CSBC has not taken effect, this sheet stays on NEC 2020 conventions until OSBI confirms the new code is live.
Sheet 07
Equipment Datasheets
UL-listed manufacturer spec sheets for modules, inverter, racking, and MLPE — organized per the documentation requirements of the specific Connecticut municipal AHJ and the Eversource or United Illuminating RRES interconnection application. 2026 Solar Energy Adjustment rate noted in the RRES program reference. ESS battery documentation included if battery storage is part of the design. Smart-E Loan program eligibility noted where applicable.
🏗️ Commercial Solar in Connecticut

Also doing commercial rooftop or ground-mount in Connecticut?

Connecticut commercial solar structural packages reference the 2021 IBC with Connecticut amendments, NEC 2020 Article 690, and RRES Buy-All or Netting Tariff interconnection documentation for Eversource or United Illuminating. Systems above 25 kW move to Level 2 interconnection with engineering review at both utilities. ASCE 7 wind and snow loads applied per municipality. Engineering covers standing-seam and EPDM rooftops, parking canopy structures, and fixed-tilt or tracker ground-mount systems. Custom scope and turnaround quoted per project.

NEC 2020 (2022 CSBC) 2021 IBC CT RRES Level 2 (>25 kW) Eversource + UI
Commercial Quote →
Scope + turnaround quoted per project
Process

How Connecticut Solar Permit Plan Sets Work

01

Submit Your Connecticut Project

Give us the municipality and street address. We confirm whether Eversource or United Illuminating serves the address, the RRES tariff track (Netting or Buy-All), the specific municipal AHJ and its permit documentation requirements, and ASCE 7 snow and wind values for the municipality.

02

Built to NEC 2020 + RRES Format

NEC 2020 Article 690 electrical with §690.12 single-device rapid shutdown. 2021 IRC or IBC with Connecticut amendments and municipality-specific ASCE 7 loads. RRES interconnection documentation for the confirmed utility and tariff, including the 2026 Solar Energy Adjustment. Connecticut-licensed PE stamp on structural sheets.

03

Delivered in 24–48 Hours

The complete 7-sheet Connecticut package ships in 24–48 hours. Every sheet is formatted for the specific municipal AHJ — not a generic Connecticut template — and the RRES interconnection documentation matches the confirmed utility and tariff. Free revisions until the Connecticut municipal building department approves.

First-Time Connecticut Clients

Try Us on Your First Connecticut Project. Free.

First time working with us? Hand over your initial Connecticut residential project and we will put together the full 7-sheet package free of charge — NEC 2020 electrical, 2021 IRC structural with municipality-specific ASCE 7 snow and wind loads, and RRES interconnection documentation for Eversource or United Illuminating including the current Solar Energy Adjustment rate.

⚠️ For licensed solar installers, EPCs, and roofing companies only. Individual homeowners and residential end customers are not eligible. One free residential plan set per company.

Claim Your Free CT Plan Set →
✓ NEC 2020 — 2022 CSBC confirmed
✓ 2021 IRC structural + PE stamp
✓ Municipality ASCE 7 snow + wind
✓ RRES Netting or Buy-All documented
✓ Free revisions until AHJ approval
FAQ

Connecticut Solar Permit Design — Frequently Asked Questions

NEC 2020. Connecticut's current code is the 2022 CSBC, based on 2021 I-Codes, effective October 1, 2022. The 2026 CSBC — which would adopt NEC 2023 — is drafted but awaiting approval from the Connecticut General Assembly's Legislative Regulation Review Committee. Until that approval occurs, NEC 2020 governs all Connecticut solar permits. Permit Design monitors the OSBI website for the official effective date.
The Residential Renewable Energy Solutions (RRES) program replaced Connecticut's legacy net metering program in 2022, after the prior RSIP solar rebate program reached its 350 MW deployment target. RRES is administered by Eversource and United Illuminating under PURA regulation and offers two tracks: the Netting Tariff (solar powers home first, excess earns retail-rate credits that roll over indefinitely) or the Buy-All Tariff (all production sold at a fixed rate for 20 years). Rates are set annually and locked for the full 20-year term at enrollment.
The 2026 Solar Energy Adjustment is $0.0402 per kWh applied to all solar production — not just exported energy — for new RRES Netting Tariff enrollees in 2026. For an 11 kW system producing about 12,925 kWh per year, this is roughly $520 annually deducted from savings, locked for 20 years. The 2025 rate was $0.005/kWh — an 8x increase. This is a key change that materially affects Connecticut solar payback calculations for 2026 new enrollees.
For most homeowners, the Netting Tariff is the better fit. Under the Netting Tariff, solar powers your home first and excess earns retail-rate credits that roll over indefinitely. Under the Buy-All Tariff, all production is sold to the utility at a fixed rate (~$0.3289/kWh for 2026 enrollees) and you buy all electricity at standard retail rates. The Buy-All Tariff is most useful for PPA structures where a guaranteed fixed payment simplifies the financial model for a third-party solar owner.
Connecticut has two investor-owned utilities: Eversource Energy, which serves most of the state including Hartford, Norwalk, Waterbury, and Danbury at approximately $0.29/kWh; and United Illuminating (Avangrid), serving the New Haven and Bridgeport shoreline area at approximately $0.28/kWh. Both administer RRES identically under PURA rules. Systems up to 25 kW use a Level 1 simplified interconnection process with a 4–8 week timeline at both utilities.
The 2022 Connecticut State Building Code — based on 2021 IBC and 2021 IRC with Connecticut amendments, effective October 1, 2022 — governs all current permits. The 2026 CSBC (2024 IBC, NEC 2023) is drafted but delayed pending legislative approval. Structural calculations reference ASCE 7 wind and snow loads for the specific municipality — northwest Connecticut towns carry significantly higher ground snow loads than coastal Sound communities.
Connecticut's building permit authority rests entirely at the municipal level — the state has 169 municipalities, each operating its own building department. Connecticut has no county-level government and no state-level residential building permit. Permit fees range from under $100 to over $1,000 for the same solar system depending on the town, and documentation requirements vary despite the 2016 Connecticut Standardized Solar PV Permit Application Supplement created to reduce that variation.
Yes. Connecticut offers a sales tax exemption on qualifying solar equipment and a property tax exemption on added home value from solar. The Energy Storage Solutions (ESS) battery rebate offers up to $7,500 for qualifying systems. The Smart-E Loan through the Connecticut Green Bank provides 4.49%–6.99% APR financing. No Connecticut state income tax credit for solar exists. The federal Section 25D residential credit ended for systems placed in service after December 31, 2025.
The timeline is uncertain. The 2026 CSBC — which includes NEC 2023 — went through public comment that closed October 2025 and was expected effective July 1, 2026. As of June 2026, it awaits Legislative Regulation Review Committee approval. The OSBI has indicated the effective date may be delayed. We monitor the OSBI for the official date and update Connecticut plan sets to NEC 2023 the moment the 2026 CSBC takes effect.
Permit Design delivers Connecticut solar permit plan sets within 24-48 hours. Every plan set references NEC 2020 under the 2022 CSBC, 2021 IRC or IBC with Connecticut amendments, ASCE 7 loads for the specific municipality, and RRES interconnection documentation for the confirmed utility — Netting Tariff or Buy-All. Free revisions until the Connecticut municipal AHJ approves.
Connecticut Solar Market — 2026

Connecticut Solar by the Numbers

~2,000 MW
Installed Solar Capacity
Connecticut reached approximately 2,000 MW of installed solar capacity in 2026, driven by both residential rooftop growth and utility-scale procurement under Connecticut's Shared Clean Energy Facility and related programs. The RRES program continues to enroll new residential customers at a steady pace despite the higher 2026 Solar Energy Adjustment.
2,200
Solar Industry Jobs
Connecticut's solar sector supports approximately 2,200 jobs across installation, distribution, and related services. The Connecticut Solar and Storage Association (CONNSSA) has been advocating for standardized instant permitting legislation — HB 5036 — that would require a statewide online permitting platform by 2028 and municipal compliance by 2029, which would significantly reduce the friction of working across 169 different permit offices.
$0.29/kWh
Eversource Retail Rate
Connecticut residential electricity rates remain among the highest in the continental US, with Eversource at approximately $0.29/kWh and United Illuminating near $0.28/kWh. High retail rates increase the value of self-consumed solar under the RRES Netting Tariff, partially offsetting the impact of the higher 2026 Solar Energy Adjustment for new enrollees.
$7,500
ESS Battery Rebate
Connecticut's Energy Storage Solutions (ESS) program offers rebates of up to $7,500 for qualifying battery storage systems, administered through Eversource and United Illuminating. With the federal Section 25D credit expired at the end of 2025, the ESS rebate is the most significant direct financial incentive for Connecticut solar customers in 2026. Smart-E Loan financing through the Green Bank supplements it.
NEC 2023 Pending
2026 CSBC Awaiting Approval
The 2026 Connecticut State Building Code — adopting NEC 2023 and the 2024 IBC — is ready but pending Legislative Regulation Review Committee approval. Its effective date was expected July 1, 2026, but is delayed. When enacted, it will require updates to rapid shutdown documentation (format unchanged but version citations shift), and will align Connecticut with the most current national electrical standard.
169 Towns
Most Complex AHJ Landscape in the Northeast
Connecticut's 169 independent municipal AHJs create the most fragmented permitting environment in the Northeast. Permit fees, documentation requirements, inspector availability, and turnaround times all vary town by town. Proposed legislation (HB 5036) would create a statewide instant permitting platform — but until enacted, every project requires confirming the specific town's requirements.
Connecticut AHJ Rejections

Top 3 Reasons Connecticut Solar Permits Get Rejected

Three plan set issues account for most Connecticut municipal permit delays across the state's 169 building departments.

01
NEC 2023 Formatting Before the 2026 CSBC Takes Effect
The 2026 CSBC (NEC 2023) is ready but not yet officially in force. Some installers anticipating the July 2026 effective date submitted plan sets with NEC 2023 rapid shutdown formatting — §690.12(D) reorganized labeling, single-device references to the 2023 edition — before the LRRC approved the new code. Connecticut building inspectors reviewing these under the 2022 CSBC (NEC 2020) flag the version mismatch.
2022 CSBC NEC 2020 · 2026 CSBC pending LRRC
How we prevent it: Connecticut plan sets reference NEC 2020 under the 2022 CSBC until the OSBI publishes the official 2026 CSBC effective date. We monitor and switch the moment it's enacted.
02
Generic CT Plan — Missing Municipality-Specific Requirements
Connecticut's 169 municipalities each have their own permit documentation expectations. A plan set built to a generic "Connecticut" format without checking the specific town's requirements will often miss details — fire setback standards (some towns use IFC provisions, others OSFM guidelines), specific title block information, or fee schedule documentation. This is especially common when installers move a template between towns without updating municipality-specific fields.
169 municipal AHJs · CT Standardized PV Supplement
How we prevent it: Every Connecticut plan set is built for the specific municipality's documented requirements — not adapted from a prior-town template without a requirements check.
03
Northwest CT Snow Load Underspecified
Litchfield County towns — Norfolk, Canaan, Goshen, Torrington, Winchester — carry ASCE 7 ground snow loads well above what applies in coastal Fairfield or New Haven County. Structural calculations using statewide Connecticut averages or coastal values for a northwest Connecticut rooftop will be flagged by the local AHJ or the reviewing engineer.
ASCE 7 · 2021 IRC Chapter 3 · Litchfield County pg
How we prevent it: Ground snow load and wind exposure are pulled from ASCE 7 tables for the specific municipality — Litchfield County towns receive their own verified values, not averaged with coastal Connecticut.
More on permit requirements → Residential Solar Permit Design →
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The Permit Design Commitment

What every solar installer, EPC, and roofing company can expect on every project.

✅ 24–48 Hour Turnaround on Standard Residential Solar Projects
✅ No-Cost Revisions for AHJ Corrections Related to Our Design
✅ Code-Compliant Plans Built to Current NEC, Utility & Local Requirements
✅ Support Through Permit Approval — We Don't Disappear After Delivery
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Reviewed & Verified By PE-stamped plan sets spanning all 50 states · NEC 2020 status and the pending 2026 CSBC timeline confirmed directly through CT OSBI · RRES Solar Energy Adjustment figures pulled from the PURA docket
AHJ-ReadyPer municipality
150+Installer partners
50US states covered
169 TownsAll CT municipalities
Permit SupportThrough AHJ approval
Last reviewed: June 2026·About Permit Design →
NEC 2020 (2022 CSBC)RRES Netting / Buy-All169 Municipal AHJs$0.0402 Solar Energy Adj
Neighbouring States

Solar Permit Plan Sets — Northeast States

🦞MassachusettsNEC 2020 🗽New YorkNEC 2020 ⚓Rhode IslandNEC 2023 🏝️New JerseyNEC 2017 🦞MaineNEC 2023

Connecticut Solar Permits —
Municipality-Specific. RRES-Ready.

NEC 2020 · 2021 IBC + IRC · RRES Netting or Buy-All
169 Municipal AHJs · Eversource + UI · 24–48 Hours

Order CT Plan Set →Contact Us
First-time Connecticut client? Your first residential plan set is on us. Mention "free trial" in your order notes.