2026 Cambridge (02139) Line-Item Benchmark Schedule Labor Index: 1.37x
Use this schedule when reviewing quotes from contractors in Cambridge, MA. Quotes exceeding these ranges by more than 18% typically contain dealer financing markups or unitemized overhead.
| Eversource / National Grid Benchmark (02139) | Without Solar (Utility Tariff) | With 10.6 kW Solar + Battery | Net Homeowner Impact |
|---|---|---|---|
| 2026 Residential Electric Rate | $0.350 / kWh (+34% in 3 yrs) | $0.068 / kWh Levelized | Locks in hedge against utility rate hikes |
| System Investment & 30% Federal Tax Credit | $0 Upfront ($4,836/yr forever) | Gross: $41,388 / ITC: -$12,416 | Net Cost: $28,972 (6 yr payback) |
| 25-Year Cumulative Utility Spend vs. Savings | -$166,842 | +$137,870 Net Savings | Includes 4.4 hrs/day peak solar irradiance |
Interactive 02139 Property Customizer Real-Time Math
Local Code, Rebate & Insurance Mandate Notes for ZIP 02139
Insurance & Wind/Hail Rule (Middlesex County): Massachusetts sixth-edition building code mandates high-wind starter strips and sealed roof decks.
2026 Incentives & Utility Rebates: Mass Save $10,000 Whole-Home Heat Pump Rebate + 0% HEAT Loan (up to $25,000)
Permitting Authority: All structural roofing, electrical panel, and mechanical replacements in 02139 must be permitted through City of Cambridge Building & Permitting Division (Middlesex County) (Design Wind Speed: 115 MPH).
Frequently Asked Questions — Cambridge, MA (02139)
What is the current electric rate for Eversource / National Grid in 02139?
Residential customers in Cambridge, MA (02139) served by Eversource / National Grid pay an average of $0.350/kWh, following a 34% tariff increase over the past 3 years.
How fast is the solar payback period in Cambridge, MA (02139)?
With 4.4 peak sun hours per day and the 30% federal tax credit ($12,416 savings on an 10.6 kW system), the average payback period in 02139 is 6 years, generating $137,870 in cumulative 25-year savings.