Published
Massachusetts ADU loan guide: up to $250K through MassHousing, 2026 income limits by county, your lender, Boston aid, and the funding-gap math.
ADU financing has expanded significantly with lenders recognizing the value these units add to properties. The most common options include home equity lines of credit (HELOCs), cash-out refinances, ADU-specific construction loans, renovation loans like FHA 203(k), and personal savings.
Each option has different qualification requirements, interest rates, and repayment structures. The right choice depends on your existing equity, credit score, and how quickly you need access to funds.
HELOCs offer flexibility with draw-as-you-need funding and interest-only payments during construction, but rates are variable. Cash-out refinances lock in a fixed rate but replace your entire mortgage. Construction loans fund the build in phases but convert to permanent financing after completion.
ADU-specific loan products from companies like RenoFi and Point allow you to borrow against the future value of your home after the ADU is built — a significant advantage if you have limited current equity.
Most lenders require a minimum credit score of 620-680, a debt-to-income ratio below 43%, and at least 15-20% equity in your home. Some ADU-specific lenders have more flexible requirements, particularly if the projected rental income strengthens your application.
Prepare your documentation early: two years of tax returns, recent pay stubs, bank statements, and a detailed construction estimate from a licensed contractor will be required by virtually every lender.
A well-built ADU typically adds 20-30% to a property's appraised value while generating $1,500-$3,500 per month in rental income depending on location and size. At median rental rates, most ADU owners recoup their investment within 5-8 years.
The ROI calculation should include not just rental income but also property value appreciation, tax benefits, and the flexibility value of having additional living space for family members or a home office.
