What a custom home inquiry is worth at 7% mortgage rates

Freddie Mac’s weekly survey landed at noon yesterday, and the figure every builder we talk to was watching went the wrong way. The 30-year fixed rate averaged 7.28% as of October 1, up from 7.03% the week before and 6.34% a year ago. The Federal Reserve raised its target range by a quarter point at its September meeting, to 3.75% to 4%, and NAHB reported that builder confidence fell three points to 32 the same month. The natural reaction is to cut marketing until rates settle down. For a custom builder that is usually the wrong cut, and the arithmetic below shows why.

Rates bite spec buyers harder than custom clients

NAHB’s research on custom building says the market “is less sensitive to the interest rate cycle than other forms of home building but is more sensitive to changes in household wealth and stock prices.” A family hiring a custom builder usually owns land or is buying it, and in the conversations we have with builders, often brings equity from a current home or savings to the table. They still feel the rate. They feel it less than a first-time buyer comparing monthly payments on a finished spec house.

The market has cooled anyway. NAHB counted 49,000 custom starts in the second quarter of 2026, 9% fewer than a year earlier, and put custom building at 20% of single-family starts on a one-year moving average. Smaller than last year, but still one start in five.

The arithmetic of one signed contract

The Census Bureau’s latest Characteristics of New Housing release put the median contract price for a contractor-built home started in 2025 at $404,000. Two published percentages help turn that into a marketing budget, with a caution attached: both come from NAHB’s Cost of Constructing a Home survey for 2024, which covers builders in general and leans toward spec homes, so treat them as a rough frame rather than a custom benchmark.

• Margin. The survey put the average builder profit margin at 11.0%. On a $404,000 contract the same margin would be about $44,400.
• Marketing. Marketing costs came to 0.8% of the average price. Applied to the median contract, that is roughly $3,200 per home.

Now set those against published lead costs. LocaliQ’s 2025 home services benchmarks, covering April 2024 to March 2025, have no category for builders. The nearest, Construction & Contractors (General), had a median cost per Google search lead of $165.67 and a median conversion rate of 2.61%. At that median, $3,200 buys about 19 search inquiries.

So the question is not really what a lead costs. If one of those 19 inquiries becomes a contract, your marketing cost per home sits right at the survey’s 0.8%. If it takes 40 inquiries to sign one family, the cost per home rises to about 1.6% of the contract, and the margin still dwarfs it. What decides the outcome is how many inquiries reach a design agreement, and that depends almost entirely on what happens after the form arrives.

What the published lead costs leave out

Cheap leads are tempting in a slow quarter. WordStream by LocaliQ’s 2026 Facebook ads benchmarks, published in September and covering April 2025 to June 2026, put the median cost per lead for lead-form campaigns at $42.95 in Home & Home Improvement and $13.74 in Real Estate. The real estate figure looks like a bargain, but in the campaigns we have seen, most of those forms come from people scrolling listings, not families ready to build on a lot they own.

The other gap is the phone. Invoca’s 2026 home services report found that the construction group answered just 32% of calls with a person, the lowest of the nine groups it measured. An inquiry that cost $165 and rang out is the most expensive lead a builder buys.

Put plainly:

• Search inquiries arrive closer to a decision and cost more per lead.
• Leads from Facebook ads cost less and need far more follow-up before anyone sits down at a design table.
• A missed call erases the difference between them, whichever channel paid for it.

Where the next dollar goes at 7%

NAHB’s September analysis put the custom premium at its widest since 2011: a median of $171 per square foot for custom homes started in 2025, against $152 for spec homes once lot values were excluded, a gap of 12.6%. In the Pacific division the gap ran the other way, with the custom median roughly a quarter below the spec median of $227. Families notice these numbers. A builder who explains, on the site, what the client gets for the difference sells against spec inventory instead of losing to it.

In order of where we would put money this quarter:

• Fix call handling first, so every call is answered or returned within minutes, before buying more of anything.
• Put floor area, lot, build time and budget guidance on portfolio pages, so the inquiries that arrive are already qualified.
• Keep search campaigns on build-on-your-lot and county terms running through the winter design months, when families are choosing.
• Use Facebook and Instagram to keep finished homes in front of parade visitors and people who have browsed your site, and judge those campaigns on design meetings booked, not form fills.
• Track each inquiry through to a contract, so next year’s budget is set by what signed rather than by what was cheap.

What we are telling clients

• Do not cut search spend in October on the strength of one week’s rate news; review it in January against design meetings booked.
• Work out your own cost per signed contract for the last two years, even roughly, before anyone sets a budget for next year.
• Add a “waiting on lender” stage to your pipeline and check in with those families every few weeks.
• Write a page that explains your price per square foot against spec homes in your area, using your own numbers.
• Call your own office at 10 am on a weekday while the site supervisor is out, and see who answers.

Rates will move again, in one direction or the other, and nobody we know can say which. The builders who come out of a slow stretch with a full spring tend to be the ones whose inquiries kept arriving and kept getting answered. Our page for custom home builders lays out the order we work in, and our Google Ads work shows how we run search for clients who take most of a year to decide.