Borrow against your home only when you need it, and pay interest on nothing else

A home equity line of credit lets you borrow against your home without taking the whole amount at once, and you pay interest only on the balance you are actually carrying. That single difference is why a line suits some jobs far better than a mortgage advance does, and why it is the wrong tool for others. I compare 50+ lenders on one application, and the terms attached to a line vary more between them than mortgage rates do.

When a line beats taking the money in one go

The clearest case is a renovation. You know roughly what the project costs and you know the number will move. With a refinance you take the whole estimate up front and start paying interest on all of it, including the part still sitting in your account in month four. With a line you draw as the invoices arrive, and the interest follows the actual spending.

Here is what that looks like with numbers on it. Say the renovation is $75,000, drawn evenly over eight months, and compare it against refinancing the same $75,000 in one advance. Rates are illustrative.

	Line of credit at 6.20%	Refinance advance at 4.49%
Money outstanding, on average, over the eight months	$42,188	$75,000
Interest paid during the project	about $1,744	about $2,245
Interest to carry $75,000 for a further year	about $4,650	about $3,368

The line wins while you are drawing, even at a materially higher rate, because you are not paying for money you have not spent yet. The mortgage wins once the project is done and the balance is just sitting there. That is the actual shape of the decision, and it points at a third answer people rarely get offered: use the line during the build, then fold the settled balance into the mortgage at renewal, when there is no penalty to restructure.

The same logic applies to a business with uneven cash flow, to a parent helping with tuition over several years, and to anyone who wants a buffer sitting behind them without paying to hold it. If the amount is known and fixed, a refinance is usually cheaper. If the amount is a range, the line usually wins in practice.

The two limits that decide the size

Two ceilings apply, and people routinely quote the wrong one. A standalone home equity line of credit is capped at 65 percent of the home’s value, which means you need more than 35 percent equity to have one at all. Where the line is combined with your mortgage on a readvanceable product, the mortgage and the line together are capped at 80 percent, so you need at least 20 percent equity.

On a $600,000 home carrying a $300,000 mortgage, the combined ceiling is $480,000, so the room available is up to $180,000. That is the arithmetic ceiling. Reaching it is a separate question, because your income and credit still have to support the payment, and the federal stress test applies here the same as on a mortgage: you qualify at the greater of 5.25 percent or your rate plus two percent.

Readvanceable, standalone, or second position

Three shapes exist, and which one you are offered depends mostly on where your mortgage already sits.

Readvanceable. The line is bundled with your mortgage at the same lender. As you pay principal down, the available limit grows automatically, up to the combined 80 percent ceiling. It is the most flexible version and the most common one attached to a renewal.

Standalone. A line on its own, on a home with no mortgage or with the mortgage elsewhere, capped at 65 percent of value.

Second position. A line behind another lender’s mortgage. Fewer lenders do it and the rate is higher, because they rank behind your existing lender if anything goes wrong. It is a common answer for someone who wants access to equity without breaking a mortgage they like, and it sits close to a second mortgage in purpose while behaving like a line in use.

The three things nobody mentions when they sell you one

It is easy to carry forever. Most lines require only the interest each month, so a balance can sit unchanged for years while feeling perfectly manageable. That is not an argument against them. It is an argument for deciding the repayment plan at the start, while the borrowing still has a shape, rather than discovering in year six that the balance has never moved. If you would not accept a 20-year amortization on the same money, do not accept an indefinite one by default.

The rate moves, and the lender can move it. A line carries a variable rate tied to prime, and your lender may change it. A federally regulated lender has to notify you in writing within 30 days of an increase, which is a disclosure rule rather than a limit on the change. If a moving payment would keep you up at night, that pushes the answer toward a fixed refinance instead.

The limit can count against you even when unused. Many lenders assess your next application on the payment the full approved limit would carry, not on the balance you are actually holding. An untouched $150,000 line can quietly reduce what you qualify for on your next purchase. Not every lender does this, and the difference matters if you plan to buy a rental or move within a couple of years. Sizing the line to what you will use is sometimes worth more than sizing it to what you can get.

Collateral charges, and what they mean at your next renewal

A home equity line is registered against your title as a collateral charge, and usually for more than you are borrowing, sometimes for the full value of the home.

The upside is real: you can borrow more later without a new registration, which is what makes a readvanceable product convenient. The cost shows up at the far end. Moving a collateral charge to a new lender at renewal typically means discharging and re-registering it, with legal fees a plain mortgage switch would not attract. Some incoming lenders cover that cost and some do not.

None of this makes a collateral charge wrong. It makes it a thing to know you are signing, because it shapes what your next renewal looks like.

Using a line to buy something else

Two uses come up constantly, and both work, with conditions.

A down payment on a rental. Equity in your home is a legitimate source of the 20% a rental property requires. The lender on the rental will count the payment on the borrowed money against you, so the arithmetic has to work with both loans in the picture. Doing that calculation before you write an offer is the whole job.

Clearing higher-cost debt. Moving credit card balances onto a secured line at a fraction of the rate is arithmetically obvious and behaviourally risky, because the cards are now empty. Where it works, the cards get closed or cut back and the line gets a repayment schedule. Where it fails, the balances come back and now there are two. A structured debt consolidation exists precisely because that failure is common enough to plan around.

I will ask what the money is for. Not to judge it, but because the answer changes whether a line is the right tool.

Interest-only is a payment, not a plan

This is the section I would keep if I had to delete the rest of the page.

Take a $50,000 balance on a line at an illustrative 6.20%. The minimum payment, interest only, is about $258 a month. It never changes, the balance never falls, and ten years of paying it costs $31,000 and leaves you owing the same $50,000 you started with.

Now put a schedule on the same balance:

Repayment plan	Monthly payment	Interest paid	Balance after
Interest only, 10 years	$258	$31,000	$50,000
Paid off over 10 years	$560	$17,217	$0
Paid off over 5 years	$971	$8,278	$0

The difference between the first row and the second is about $302 a month, and it is the difference between borrowing and drifting. When I set a line up with a client, we pick one of the lower rows and set the payment there on purpose. The minimum is what the lender requires. It is not what you should pay.

How a line actually gets approved

Four things decide it, and they are checked in this order.

Equity. The limit comes off the home’s value, so the value has to be established. Most lenders will accept an automated valuation on an ordinary suburban property, which is quick and cheap. On an acreage, an unusual property or anything rural, expect a full appraisal and build a week or two into the plan for it.

Income. A line is qualified like a mortgage, at the greater of 5.25 percent or your rate plus two percent, and on the full limit rather than on what you intend to draw. Asking for a bigger limit than you need can be the reason an application does not fit.

Credit. Applying involves a credit check like any mortgage application. Afterwards the line behaves like other revolving credit: a high balance against the limit weighs on your score, and the unused room can affect what another lender approves later.

The property itself. Rental properties, acreages with outbuildings and homes with non-conforming suites all narrow the lender list. It rarely stops the file, but it changes who is looking at it.

What it costs to set one up

A line is cheaper to establish than most people expect, and the costs are predictable rather than hidden.

There is usually a property valuation, which is either an automated estimate at little or no cost or a full appraisal you pay for. There is registration of the charge against your title, which involves a lawyer or a title services company, and in Alberta the land titles registration fees themselves are modest because the province has no land transfer tax. Some lenders charge an annual fee on the line and some do not, and some waive the setup costs entirely as part of the offer.

None of these numbers are large. They matter because they are the part a lender competes on quietly, and comparing them is part of what I do with an offer you have already been handed.

Why comparing matters more here than on a mortgage

Mortgage rates cluster. HELOC terms do not. The spread over prime, whether the line is standalone or readvanceable, whether a lender will sit in second position, the fees, the appraisal requirement, and how much of the limit can be converted into a fixed portion all differ substantially between lenders. Two offers that look identical on the headline rate can be quite different products.

That is the case for putting one application in front of 50+ lenders rather than accepting the line your own bank attaches to your renewal without discussion.

When I would tell you not to

• When the borrowing has no end date and no plan attached to it.
• When the amount is known, fixed, and long-lived, in which case a refinance at a lower fixed rate costs less.
• When a variable payment would worry you enough to affect how you sleep.
• When the real problem is monthly cash flow rather than a one-time cost, because a line will paper over that for about a year and then make it worse.

What happens when you call

We talk about what you are borrowing for and what you already owe, and I will tell you whether a line, a refinance, or leaving things alone is the better answer. If your bank has already offered you one, bring the paperwork and I will read it against the market.

The conversation is free, there is no obligation, and there is no credit check just to have it.

Sources: the 65 percent and 80 percent limits, the equity required for each type, the variable rate, interest-only payments, the 30-day notice on a rate increase and the definition of a readvanceable mortgage all come from the Financial Consumer Agency of Canada’s page on home equity lines of credit. Interest figures in the comparison are illustrative, calculated on simple interest over the periods shown.