Housing Research Digest: Week of September 21, 2026

This is the first edition of a new weekly feature alongside the regular market roundup: a deeper look at the research behind the headlines. Each week we read the housing and mortgage research newsletters that land in our inbox — the multi-chart analyses, the methodology notes, the forecast revisions — and pull out what actually matters for buyers and sellers here in the Fox Valley. The goal isn’t to hand you industry talking points. It’s to give you the same information we use to form our own view, numbers and sources included, so you can form yours.

Divergence, twice over

National for-sale inventory is climbing. Core Community Mortgage reported active listings up 5.0% year-over-year and near the highest level since 2019. The REALTOR Association of the Fox Valley (RAFV) put a similar number on it from a different angle: 4.9 months of supply nationally, a 10-year high.

Locally, the picture looks different. RAFV’s August figures for Kane and Kendall counties combined show 1.6 months of supply, 800 closed sales — flat year-over-year against a 1.2% national decline — and a median sale price of $405,000, up 5%. That’s real strength, though it’s worth remembering RAFV is a REALTOR trade association with a direct interest in describing its members’ market in favorable terms.

The more useful split is the one within the Fox Valley itself. Kane County: $409,995 median (up 6% year-over-year), 600 closed sales, 1.4 months of supply, homes averaging 29 days on market. Kendall County: $400,000 median (up 3%), 200 closed sales (up 8%), 2.2 months of supply, and days on market up 62% to 47. Kane is still tight enough to favor sellers outright. Kendall is loosening in a way that, on a smaller scale, is starting to echo the national trend — more inventory, slower absorption, less pricing power. If you’re weighing a move in either county, the strategy that made sense a year ago may not be the one that makes sense today, and it isn’t the same strategy in both places.

The Fed raised rates, and “7%” is a forecast, not a fact

The Federal Reserve raised its target range a quarter point to 3.75–4.00% on September 16 — its first increase in three years. The 30-year fixed jumped from 6.76% to 6.95% in the days after, the highest since January 2025.

National Association of Realtors chief economist Lawrence Yun has been forecasting 7% as the new baseline, with the message that waiting for rate cuts isn’t a winning strategy. That’s worth separating into two pieces: the 6.95–7% rate itself is measured, current data. Yun’s claim that it’s a durable new floor is a forecast — a reasonable one, but a forecast, from an economist whose organization benefits when buyers and sellers transact now rather than wait. Market-implied odds of another Fed move by the October 28 meeting sit close to a coin flip, which reads more like genuine uncertainty than a confident case for a permanent 7% floor.

Underwriting, not price, is where deals are dying

A research letter from ResiClub (Lance Lambert) this week dug into why FHA loans have become a bigger share of large homebuilders’ sales since the pandemic-era boom ended. The range across builders is wide — from 3% of buyers at Toll Brothers (average price near $1 million) to 53% at LGI Homes (average price under $370,000). Part of the shift is a return to normal after the boom years pulled in wealthier, cash-flush buyers; part of it is genuine affordability strain, with builders leaning on in-house lenders and FHA’s looser qualifying standards to keep marginal buyers in the game.

Locally, RAFV’s data describes a version of the same squeeze playing out in conventional financing: deals are increasingly failing at the lender’s debt-to-income check rather than at inspection. The math is stark — the move from 6.26% to 6.95% on rates, compounded by rising taxes and insurance, can erase $60,000 to $100,000 of a buyer’s borrowing power in the middle of a transaction. The practical takeaway for anyone under contract: re-verify your rate lock, tax estimate, and insurance quote well before closing, not after.

Worth noting: the national FHA-builder story is concentrated in the Sun Belt and among large production builders. Fox Valley’s active new-construction pipeline is smaller-scale and doesn’t carry that same exposure — but the underlying mechanism, financing failing at underwriting rather than at the table, applies here too.

Negotiating leverage has a geography

Redfin’s latest seller-concessions data put the national rate at 44.7% of home sales — a six-year high — versus 21.9% in the Chicago metro area. A concession, in Redfin’s definition, is seller-funded help with closing costs, repairs, or a rate buydown, not a price cut. That gap is independent confirmation, from a source with no stake in our local market, of what the Fox Valley numbers already suggest: sellers here are conceding roughly half as often as the national sample.

On the buydown question specifically, the math is worth having handy. On a $500,000 home at 20% down and 6.5%, a $10,000 price cut saves a buyer about $51 a month. A seller-funded 2-1 rate buydown costs the seller a similar amount but saves the buyer roughly $500 a month in year one. Two independent sources — a mortgage lender’s newsletter and RAFV’s own data — reached the same conclusion this week: for now, buydowns are outperforming price cuts as a negotiating tool.

What we’re watching

The Fed’s next meeting is October 28, with market odds close to even on another move. Kendall County’s next monthly read will tell us whether this month’s slower pace is a trend or a blip. And we’re keeping an eye on financing conditions for condo buyers in Aurora and Naperville specifically, where building-level repair and litigation issues can sink a loan even when the buyer is fully qualified.

As always, if you’re weighing a move and want to talk through what any of this means for your specific situation, reach out — happy to help you think it through.