Columbus Shows What a Four-Year Supply Wave Does to Rent Growth

The Census Bureau's Q2 2026 residential vacancies release, published July 28, 2026, puts the national rental vacancy rate at 7.3 percent. That number is unchanged from Q2 2025's 7.0 percent and statistically indistinguishable from Q1 2026's 7.3 percent — three consecutive quarters of flat vacancy at a level that, in isolation, reads as a stable market. It is not a stable market. The Census Bureau headline is a national average that averages together metros running vacancy at 4 percent with metros running vacancy at 10 percent, and the result tells an independent landlord almost nothing about the submarket where they are underwriting a deal.

The detail is in the metro. And in the delivery pipeline.

The Census Bureau and Department of Housing and Urban Development released their joint new residential construction data for June 2026 on July 17. Building permits, which lead housing starts by several months, came in at a seasonally adjusted annual rate of 1,367,000 units — down 3.0 percent from the revised May rate of 1,410,000 and down 2.3 percent from the June 2025 level. Permit issuance is contracting. That contraction, if it persists, will show up in actual unit deliveries 12 to 18 months from now. The pipeline that is delivering units into rental markets today was permitted 12 to 18 months ago, when permit levels were running higher. The oversupply visible in current vacancy data is a lagging indicator — it reflects the delivery wave from the 2023-2024 permit peak, not the current permit trough.

The Mortgage Bankers Association's commercial and multifamily intelligence arm, drawing on Yardi Matrix data, reported July 23 that U.S. multifamily advertised rents increased 0.7 percent during Q2 2026 and 1.0 percent during the first half of 2026. The July monthly reading, reported separately via the Apartments.com multifamily rent growth report, showed a further deceleration: national multifamily rent growth slowed to 0.03 percent in July 2026, with annual growth holding at approximately 1.0 percent. That is the number. National rent growth is running at 1.0 percent annually in mid-2026 — not the 5 to 10 percent annual growth that was embedded in every pro forma from 2020 to 2022, and not the 3 to 4 percent growth that investors underwrote as a baseline assumption as recently as 2024.

The independent landlord underwriting a deal today cannot use 3 percent annual rent growth as a baseline assumption. The current market is running at 1 percent. In the metros where the supply wave is most pronounced, the assumption is 0 percent, or worse.

Today's Lens: Columbus, Ohio and the Four-Year Oversupply Signal

The Columbus, Ohio multifamily market entered Q2 2026 having absorbed the largest delivery wave in its recorded history. Deliveries peaked near 9,500 units in late 2025 per Swiss Realty. Vacancy was around 10 percent in 2026 per CoStar — roughly 200 basis points above the national average of 7.3 percent and an all-time high for the metro. Trailing 12-month rent growth slowed toward roughly 1.0 percent (verify the current figure in a current market report). The trajectory is flattening toward zero.

The Columbus delivery wave is not a new phenomenon. The Swiss Realty Group market analysis notes that supply has outpaced demand in Columbus for four consecutive years. The market has been absorbing the consequences of a permitting and construction surge that began when interest rates were at near-zero lows and institutional capital was chasing multifamily yield. The units that were permitted and built during that period are the units that are competing for tenants in Columbus today. The result is a landlord's market in the most literal sense: when vacancy runs at 10 percent, tenants have negotiating leverage on rent and concession packages that they do not have when vacancy runs at 4 or 5 percent.

The Columbus data point matters for independent investors outside Ohio for a specific reason. The national rental vacancy headline of 7.3 percent masks a distribution. The metros that ran the largest construction booms between 2020 and 2024 — Sun Belt metros with abundant land, Phoenix, Atlanta, Dallas, Nashville, and secondary markets like Columbus, Austin, and Raleigh-Durham — are the metros where vacancy is running above the national average and where rent growth is running below it. The metros where construction activity was more restrained are running tighter vacancies and firmer rent growth. The national average tells you that the average landlord in America is sitting at 7.3 percent vacancy. The distribution tells you that the landlord in a Sun Belt or oversupplied secondary market is sitting at 9, 10, or 12 percent vacancy, with the rent growth trajectory to match.

For independent investors underwriting acquisitions, this has a direct implication for the DSCR calculation. A property underwritten at 1.20 DSCR with a rent growth assumption of 2.5 percent annually may arrive at a DSCR of 1.05 by year three if actual rent growth comes in at 0.5 percent while operating costs grow at 3 percent. The growth assumption is where deals break. In a market running 10 percent vacancy and 1 percent rent growth, the conservative assumption is 0 percent rent growth for the full hold period — not 2 percent, not 1.5 percent, and certainly not the 3 percent that appeared in the broker's deal memo.

One Market, One Metric

Columbus, Ohio. Vacancy: around 10 percent in 2026 per CoStar. The metric: 200 basis points above the national rental vacancy rate of 7.3 percent.

That spread is not a statistical artifact. It is a direct consequence of what happens when a metro receives nearly 9,500 units in a 12-month period while employment and household formation grow at their natural rate. The units that arrive as new supply do not instantly create new tenants. They compete with the existing rental stock, pulling down occupancy in older properties and putting downward pressure on rents in the near term. The vacancy rate is the market's way of clearing that excess supply — it is the gap between the number of units available for rent and the number of households actively seeking to rent in that period.

The roughly 10 percent vacancy rate means that roughly one in ten rental units in Columbus is vacant and available for lease at any given time. In that environment, a landlord who raises rent at renewal is not simply pricing against their own unit's desirability — they are pricing against the 10 percent of the market that is actively available and competing for the same tenant pool. The asking rent that clears the market in a 10 percent vacancy environment is not the same asking rent that clears the market at 5 percent vacancy.

The Columbus metro also illustrates a specific long-lead-time dynamic that independent investors should track in their own target markets. The peak deliveries in Columbus occurred in late 2025 per Swiss Realty. The permits that generated those deliveries were pulled 12 to 18 months earlier. Current Census Bureau permit data shows issuance running below year-ago levels nationally. If that trend holds, the delivery wave that pushed Columbus to around 10 percent vacancy in 2026 per CoStar will crest as the pipeline clears, and the subsequent supply contraction will set up the conditions for vacancy compression and rent firming in 2027 and 2028. The independent investor who buys in Columbus today at a conservative rent assumption is buying at the peak of a supply cycle — and may be positioned to benefit from the demand recovery that follows the supply contraction.

The question is whether your target metro is in an absorption phase, a peak-delivery phase, or a supply-contraction phase. The answer changes the rent growth assumption in your pro forma. And that assumption is the variable that most directly determines whether your DSCR survives the hold period.

Today's Five-Minute Action

Go to the Census Bureau New Residential Construction data portal at census.gov/construction/nrc and pull the current month's permit data for your target metro. Look specifically for the 12-month rolling permit total for your state or metro area — this is a leading indicator that shows whether the supply wave that will arrive in 12 to 18 months is building, stable, or declining. Then cross-reference that against the most recent vacancy and rent growth data for your target metro from Apartment List, Apartments.com, or the Swiss Realty Group Columbus market reports to establish whether your market is in a supply-absorption phase or a supply-contraction phase.

The Census Bureau permit portal publishes state-level and metro-level permit data monthly, with a 12-business-day lag. The Q2 2026 vacancy data from Census is current as of the July 28 release. The combination of current permit trajectory and current vacancy rate tells you the supply-demand balance in your target submarket — and tells you whether your pro forma rent growth assumption is consistent with what the market is actually doing, or whether it needs to come down.