ADU Financing · 2026
Home Equity Loan vs HELOC for an ADU
A home equity loan gives you a single lump sum upfront with a fixed repayment schedule, like a second mortgage. A HELOC (home equity line of credit) gives you a revolving credit line you draw from as needed, similar to a credit card secured by your home. Both borrow against the equity you’ve built in your primary residence, but the shape of the money, and how you pay it back, is very different. Which one fits an ADU project better usually comes down to how your builder prices the job and how predictable your draw schedule is.
The short version: A home equity loan hands you a fixed amount at closing and you repay it on a set schedule from day one. A HELOC opens a credit line you draw from over time, so you’re generally only paying interest on what you’ve actually used so far. For an ADU built at a fixed contract price with a permitting budget included, either can work well, but the details of rates, draw periods, and repayment terms vary by lender and change over time, so it’s worth confirming exact numbers with a lender before you commit to either one.
How a home equity loan works
A home equity loan is a lump sum, secured by the equity in your existing home, paid out all at once when the loan closes. From there it behaves like a traditional installment loan: a fixed interest rate, a fixed monthly payment, and a fixed payoff date, often somewhere between five and twenty years out.
Because the full amount lands in your account on day one, interest starts accruing on the entire balance immediately, even if your ADU build won’t actually need that cash for months. That’s the main tradeoff: predictability in exchange for paying for money you haven’t used yet.
How a HELOC works
A HELOC opens a line of credit against your home’s equity, up to an approved limit, that you draw from as you need it rather than receiving all at once. Most HELOCs have two phases: a draw period, where you can pull funds and typically make interest-only payments on what you’ve drawn, followed by a repayment period, where the line closes to new draws and you pay down principal and interest on whatever balance remains.
Interest on a HELOC usually accrues only on the portion you’ve actually drawn, and the rate is typically variable, tied to a benchmark index that moves with the broader rate environment. That variability cuts both ways: payments can go down as well as up over the life of the line, which is part of why loan terms and eligibility should always be confirmed directly with a lender rather than assumed from a general description like this one.
Why a HELOC often fits ADU construction well
ADU construction doesn’t consume cash all at once. Money moves out in phases, permitting, site work, factory production, delivery, hookups, so a credit line you draw against as those phases hit can line up more naturally with the build than a lump sum sitting in an account for months.
With a HELOC, you’re generally not paying interest on the full project cost from the moment you sign. You draw as costs come due and the balance, and the interest on it, grows along with the project. For homeowners who want to keep carrying costs as low as possible during construction, that structure is often the more efficient one.
When a lump-sum home equity loan can be the cleaner fit
A fixed lump sum makes the most sense when your baseline project cost is already known and won’t move. That’s exactly the situation Framework First is built around: a contract price, from $180,000 for a compact studio up to $557,000 for a full three-bedroom model, that’s set before construction starts and includes a permitting budget along with plans, foundation, the factory build, delivery, utility hookups, appliances, and final inspection. Exact permit costs are set by your city and county and confirmed in your feasibility study before that price locks in.
When you already know the number, a home equity loan lets you borrow exactly that amount, lock in a fixed rate and fixed payment at closing, and never worry about a variable rate moving your payment around mid-project. For homeowners who value certainty over flexibility, that predictability can outweigh the cost of paying interest on the full balance sooner.
Home equity loan vs HELOC at a glance
| Home equity loan | HELOC | |
|---|---|---|
| How funds arrive | One lump sum at closing | Revolving line, draw as needed |
| Interest accrues on | The full amount, from day one | Only the portion you’ve drawn |
| Rate structure | Typically fixed | Typically variable, tied to an index |
| Payment pattern | Fixed monthly payment from the start | Interest-only during the draw period, then principal and interest |
| Best fit for | A known, fixed total cost | A phased project with costs spread over time |
| Where it fits an ADU build | A locked contract price you want to fund all at once | Drawing funds in step with construction phases |
Connecting this to your ADU build
Neither option is inherently better. It comes down to how your project is priced and how much rate certainty matters to you. Because Framework First prices every build as a single fixed contract, you’ll know your baseline cost before you ever talk to a lender, which makes it easy to compare what a lump-sum home equity loan versus a HELOC would actually look like for your specific number.
A good first step is running your numbers through the ADU cost calculator to see where your project lands in the $180,000 to $557,000 range, then booking a feasibility study to confirm what’s buildable on your lot. From there, our pricing page breaks down what’s included in that price, and our broader guide on how to finance an ADU in California walks through the full menu of financing options beyond just these two, including construction loans and cash-out refinancing.
Framework First doesn’t lend money or set loan terms. We can point you toward ADU-focused lending partners, but the specifics of your rate, credit approval, and repayment terms come from the lender, not from us, and those details change over time. Confirm exact figures directly with a lender or financial advisor before signing anything.
Frequently asked questions
Is a home equity loan or a HELOC better for building an ADU?
It depends on how you want to handle cash flow. A home equity loan works well when you already have a fixed, known project cost and want a predictable fixed payment from the start. A HELOC works well when you’d rather draw funds gradually as construction phases hit, so you’re not paying interest on money that’s still sitting unused. Since Framework First builds are priced with a single fixed contract amount, either structure can work depending on your personal preference for certainty versus flexibility. A lender can walk you through which one fits your specific financial picture.
Do I need a certain amount of equity to qualify for either option?
Both a home equity loan and a HELOC are sized against the equity you’ve built in your primary residence, generally the difference between your home’s value and what you still owe on it. Lenders set their own minimum equity requirements, credit score thresholds, and debt-to-income limits, and those requirements vary by lender and shift over time. The only way to know what you specifically qualify for is to apply directly with a lender.
Can I use a HELOC or home equity loan to cover the entire ADU cost, including permits and appliances?
Yes, either can be used to fund your ADU contract, which is exactly why Framework First structures pricing as one number that includes a permitting budget along with plans, foundation, the factory build, delivery, utility hookups, appliances, and final inspection. Exact permit costs are property-specific and confirmed in your feasibility study, but that defined baseline is what makes it straightforward to compare against a lump-sum loan or a HELOC’s credit limit. Your lender will confirm the maximum amount you’re approved to borrow based on your equity and financial profile.
What happens if interest rates change while I’m still repaying a HELOC?
Because most HELOCs carry a variable rate tied to a benchmark index, your payment can rise or fall as that index moves, both during the draw period and after repayment begins. A home equity loan avoids that by locking a fixed rate at closing, so your payment stays the same for the life of the loan. Neither structure is right or wrong, it’s a tradeoff between flexibility and predictability, and a lender can explain how rate movement would affect your specific line or loan.
Should I talk to a lender before or after getting a feasibility study?
Either order works, but many homeowners find it easiest to start with a feasibility study to understand what’s buildable on their lot and get a realistic project scope, then take that information to a lender to discuss financing options like a home equity loan or HELOC. Having a defined project and a firm price in hand tends to make those lender conversations more concrete and efficient.
Ready to see what your ADU could cost? Start with a feasibility study to confirm what’s buildable on your lot.