Most Connecticut homeowners fund an ADU with a second-lien loan that keeps their first mortgage intact. Here's how the main options differ — and how CT ADU's network of local banks, credit unions, and private lenders helps you match the structure to your project.
There's no single "best" ADU loan — the right one depends on how much equity you have, how you want to draw the money, and whether you need to protect a low first-mortgage rate.
A HELOC offers flexible draws (usually variable rate); a home equity loan gives a fixed lump sum and payment; renovation products can lend against the home's after-renovation value when current equity is thin; and a cash-out refinance replaces your first mortgage — usually the wrong move if that rate is low. CT ADU can connect you with local banks, credit unions, and private lenders — some who underwrite to after-renovation value, and while most large banks cap a second mortgage around 80% of value, some Connecticut lenders allow a combined loan-to-value as high as 100% for well-qualified borrowers.
Most Connecticut ADU projects are paid for with home equity, because the homeowner already holds significant value in the main house. The question is usually how to tap it — and each product behaves differently once construction starts.
This is the decision most homeowners actually wrestle with. A HELOC is a revolving line you draw from as the ADU progresses — useful when costs arrive in stages — but the rate is usually variable, so your payment can move. A home equity loan hands you a fixed lump sum at a fixed rate: more predictable, but less forgiving if the scope changes mid-project. If your budget is well-defined, certainty often wins; if the timeline is staged, flexibility can.
HELOCs and home equity loans are limited by your home's current value and existing equity. Renovation lines of credit and renovation second mortgages can sometimes underwrite against the home's after-renovation value (ARV) — what it may be worth once the ADU is complete. That can open the door when today's equity isn't quite enough. Several of the lenders CT ADU works with offer ARV-based products, though availability and rules vary by lender and program.
CT ADU is not a lender, but a big part of our job is pointing homeowners toward financing that actually fits an ADU project. Over years of Fairfield County builds we've developed relationships across three types of lenders:
Two things homeowners are often surprised to learn: some of these lenders will underwrite to the home's value after the ADU is built, and some of the second-mortgage lenders we work with allow a combined loan-to-value as high as 100% — most large banks cap around 80% — of the home's value for well-qualified borrowers. That can make a project feasible even when a traditional HELOC would fall short. These programs are case-by-case and depend on the lender, the property, and your qualification — so we help you find the right fit rather than promising a specific number.
It's tempting to chase the lowest advertised rate, but structure often matters more. An interest-only draw period or a longer term can lower today's payment while costing more over the life of the loan; a variable rate can start low and climb. Weigh the total cost and the payment structure against how long you'll hold the loan — not just the headline number. Our ADU ROI guide shows how the financing payment flows into your real return.
CT ADU helps you get the sequence right: understand your likely project scope and budget first, because the right financing structure depends on what you're actually building — then get introduced to lenders who understand ADUs, including ARV and high-LTV second-mortgage options. Explore ADU financing options, keep a low rate with second-lien financing, or test the numbers with the ROI calculator.
Tell CT ADU about your lot and goals. We'll frame a realistic scope and introduce you to lenders — local banks, credit unions, and private lenders — that fit it.
This guide is general information, not a loan offer or financial advice. CT ADU is not a lender or mortgage broker; we make informal introductions to third-party lenders. Loan availability, rates, terms, loan-to-value limits, ARV treatment, and underwriting vary by lender, program, property, and borrower, and are never guaranteed. Confirm all details with a licensed lender before applying.
The financing questions homeowners ask CT ADU most.
Neither is universally better. A HELOC gives a flexible, revolving draw that suits a staged ADU build, usually at a variable rate. A home equity loan gives a fixed lump sum and predictable payment for a well-defined budget. The right choice depends on your equity, how you want to draw funds, and your tolerance for a variable rate.
A HELOC is a revolving line of credit you draw from as needed, typically at a variable rate. A home equity loan is a one-time lump sum repaid on a fixed schedule at a fixed rate. Both are second liens that use existing equity and let you keep your current first mortgage.
Often, yes. Renovation lines of credit and renovation loans can help when current equity isn't enough, because some products consider the home's after-renovation value (ARV). CT ADU works with local banks, credit unions, and private lenders, some of whom underwrite to ARV. Availability and terms vary by lender and program.
CT ADU can connect homeowners with local banks, credit unions, and private lenders. Some of the second-mortgage lenders we work with allow a combined loan-to-value as high as 100% — most large banks cap around 80% — of the home's value for well-qualified borrowers. These are case-by-case and depend on the lender, the property, and borrower qualification.
A cash-out refinance replaces your entire first mortgage, so it's often unattractive if you hold a low rate. It can make sense if your current rate is already high or you want to consolidate. If keeping a low rate matters, a second-lien option usually fits better.
Yes. HELOCs, home equity loans, and renovation second mortgages are second liens that sit behind your existing first mortgage, so you can fund an ADU while preserving a low first-mortgage rate. See our guide on financing an ADU without refinancing.
