10/22/2026
🏡 MA ADU WARNING: a backyard cottage can cost a fortune. The hack? Convert the basement or attic you already have — and Massachusetts helps pay for it. Every program below is verified against state sources (Oct 2026):
⚖️ FIRST, THE LAW: Since February 2, 2025, one ADU is allowed BY RIGHT in single-family zones across Massachusetts — no special permit. It can be inside your home (basement/attic), attached, or detached. Max size: 900 sq ft or 50% of your home's floor area, whichever is SMALLER. It still needs building permits and must meet code (egress, ceilings, alarms).
1️⃣ MassHousing ADU Loan — up to $150,000 for ADUs in/attached to the home (up to $250,000 detached). Fixed-rate second mortgage: part at 5.25% over 20 years, part at 0% deferred — your existing mortgage stays untouched. Income up to 135% of area median (Hampden County cap $129,870). Owner-occupied single-family homes; you need plans & permits in hand BEFORE closing, and work can't start before closing. (Converting a basement or attic inside your home is covered — MassHousing's own example. Confirm your loan category with a participating lender.)
2️⃣ ADU Feasibility Study (MHP) — a professional study of your property (zoning, egress, utilities, design options, budget) for $500 or LESS out of pocket — some providers charge $0. The state pays the provider $500. One study per property, no income limit.
3️⃣ Home Modification Loan (HMLP) — 0% interest, NO monthly payments, $1,000–$50,000, repaid only when you sell or transfer. For accessible living space or an in-law ADU for a household member with a documented disability/mobility limitation (or age 60+ adaptations). Here in Western Mass it's run by Way Finders (Agawam, Springfield, Chicopee, Holyoke, West Springfield, Westfield, Northampton) and the Pioneer Valley Planning Commission elsewhere in the Valley.
4️⃣ Mass Save — start with a FREE home energy assessment. Then: 0% HEAT Loan up to $25,000 (up to 7 years) for approved energy work — insulation, heat pumps, and approved barriers like knob-and-tube wiring or vermiculite. Approved insulation is 75–100% OFF and air sealing is no-cost through the assessment. Heat pump rebates run up to $8,500. (Energy work only — Mass Save doesn't pay to finish the room itself.)
5️⃣ Town Rehab Programs (CDBG) — many Western Mass towns offer 0% deferred or forgivable loans for code, safety, and systems work. Documented local examples reach about $40,000–$50,000; Agawam's program runs through PVPC. Amounts and rules vary by town — check with yours.
🚫 CAN'T AFFORD AN ADU? FINISH THE SPACE INSTEAD.
No separate unit, no ADU rules — just finish your attic or basement as a family room, office, guest room, or gym. Funding that fits: the MassHousing Home Improvement Loan — 5% fixed, up to $50,000 over 15 years, for general (non-luxury) improvements, income limit $139,000. Published Boston-area benchmarks (not quotes): finishing an attic typically runs ~$8K–$38K and a basement ~$16K–$81K, versus ~$110K–$285K to build an ADU. Existing space usually costs far less.
🔨 KNOW BEFORE YOU BUILD (MA code basics): 7-ft ceilings for living space (6'8" is allowed for habitable basement space in MA), rooms at least 70 sq ft, an egress window in every bedroom and finished basement/attic, smoke & CO alarms, and permits with licensed electricians/plumbers. We handle all of it.
⚠️ And beware: the federal 25C/25D home-energy tax credits ENDED December 31, 2025 — they are not available for 2026 projects, whatever anyone tells you.
Murfdog Inc. builds ADUs, in-law suites, and finished basements & attics across Western Mass — since 2003.
📞 413-289-4389 — free estimates
📧 [email protected]
🌐 murfdoginc.com
Serving within 20 miles of Agawam: Agawam, West Springfield, Springfield, Chicopee, Holyoke, Westfield, Northampton, Easthampton & the Suffield/Enfield fringe.
