A lump-sum loan secured against your home’s equity, subordinate to your first mortgage. This allows you to keep your existing primary mortgage (useful if you have a low rate locked in) while tapping equity. Pros: Provides a large one-time cash infusion with a fixed interest rate and predictable payments. Cons: Typically carries a higher rate than a first mortgage and adds a second monthly payment.
A flexible, revolving credit line backed by your home equity (usually up to ~65% of your property’s value). Pros: Borrow as needed in stages and pay interest only on the amount used – ideal for an ADU build with unpredictable costs. Cons: Variable interest rates; requires at least 20% existing equity and strong credit. (It’s a great choice if you have substantial equity and want to avoid refinancing your low-rate first mortgage.)
A short-term loan that releases funds in phases as your ADU is built. Often interest-only during construction, then converts to a standard mortgage once the unit is complete. Pros: Covers large construction costs with lender oversight – the bank pays contractors at set milestones, ensuring you have funds for each stage. Cons: Requires detailed plans, lender approval, and usually a building permit in hand before the first draw; more paperwork and oversight are involved.
Refinance your existing mortgage to withdraw equity (you can typically refinance up to 80% of your home’s appraised value). This gives you a lump sum at today’s mortgage rates to fund the ADU. Pros: Often the lowest interest cost option since it’s a first mortgage rate; can simplify payments into one loan. Cons: Resets your mortgage term and could incur prepayment penalties if you break your current mortgage mid-term. You’ll also start a new, larger mortgage – something to weigh if your original rate was very low.
A personal loan or line of credit not tied to your home. Pros: Fast approval based on income/credit, and no risk to your property (no lien). Cons: Much higher interest rates and smaller limits than home-secured loans. These are best for smaller renovation projects or as a last resort to cover budget overruns, given the cost of interest.