Enterprise-owned and legacy data centers of 7–25 MW in secondary US markets are the most mispriced AI-convertible inventory in North America. Converting one to AI-ready, liquid-cooled colocation costs about $12M per MW and takes 12–18 months (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026), against $17.6M per MW (Cushman & Wakefield, 2026 Data Center Development Cost Guide, Aug 2026) and 36 or more months for greenfield.
Why are 7–25 MW enterprise data centers in secondary markets mispriced?
Three conditions combine: the assets are invisible, the end market is sold out, and the buyers who could underwrite them are looking elsewhere.
Invisibility. Data centers owned by Fortune 1000 companies whose business is not data centers are carried as property and equipment, absent from facility directories, and never valued by anyone inside the owner (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026). When a closure, spinoff, or non-core review surfaces one, the seller has no view of its value to an AI tenant.
Scarcity. North American vacancy has held at 1% for a third consecutive year, and 66 GW is under construction with 95% pre-committed (JLL, North America Data Center Report Midyear 2026, Aug 2026). Asking rents on 3–10 MW deals rose 12.5% year over year (CBRE, North America Data Center Trends H2 2025, Feb 2026), and Cushman & Wakefield expects no meaningful easing before 2030 (Cushman & Wakefield, Americas Data Center Market Shifts to Managed Growth, Feb 2026).
Buyer attention. Investment in operational assets was about $3B in 2025, down about 50% (CBRE, North America Data Center Trends H2 2025, Feb 2026), and 62% of investors prefer opportunistic development against 7% for stabilized acquisitions (CBRE investor survey via Bisnow, Aug 2025). The capital that is looking is sized for campuses, not a 12 MW building in Ohio.
What is the buy box for a Tier-2 brownfield conversion?
| Criterion | Buy box | Why it matters |
|---|---|---|
| Critical IT load | 7–25 MW | Big enough for an anchor AI tenant, below the large-cap radar |
| Ownership | Enterprise-owned or commercial | Sellers are motivated by non-core reviews, not data center valuations |
| Geography | Secondary US markets | Pricing 15–30% below primary averages; power more available |
| Status | Energized, partially active, or decommissioned | The existing interconnect is the most valuable attribute |
| Transaction | Sale, lease, or sale-leaseback | The seller can keep operating while spare halls convert |
| Horizon | Immediate to 18 months | Live sites can serve tenants inside the retrofit window |
Source: StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026.
Status is the decisive line. A decommissioned hall with a live 15 MW service agreement is worth more than a staffed hall with a 5 MW feed and a queue position, because the interconnect cannot be bought on a 12-month timeline; see how private equity underwrites data center power risk.
What does a brownfield conversion cost per MW compared with greenfield?
| Path | Cost per MW (critical IT) | Timeline | Source |
|---|---|---|---|
| Greenfield, most modern facilities | $17.6M, up 21% on the prior guide | 36+ months | Cushman & Wakefield, Development Cost Guide, Aug 2026 |
| Greenfield construction benchmark | $11.3M (2026), from $10.7M (2025); AI fit-out up to $25M | 36+ months | JLL, Global Data Center Outlook, Jan 2026 |
| Turnkey wholesale benchmark | $10–13M | Varies | StackedAI analysis, transaction-structures framework, Aug 2026 |
| Miner-site conversion to AI compute | $8–10M | Not stated | TeraWulf press release, Oct 2025 |
| Brownfield AI-ready, liquid-cooled retrofit | ~$12M (Tier-3 baseline $7–9M) | 12–18 months | StackedAI analysis, underwriting framework, Aug 2026 |
| Liquid-cooling component | $2–3M; or a $1.5–1.6M premium, 20–25% above air | Within retrofit | StackedAI analysis, Cooling Solutions note, Aug 2026; Data Center Knowledge, Apr 2026 |
Timelines: StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026.
The brownfield saving comes from the shell, site work, and interconnect, not the mechanical and electrical plant, which is why ~$12M sits above JLL’s $11.3M per MW benchmark that excludes AI fit-out. The timeline advantage is larger than the cost advantage: primary-market grid waits exceed four years (JLL, 2026 Global Data Center Outlook, Jan 2026), new large-load requests average 4.4 years (Cushman & Wakefield, 2026 Global Data Center Market Comparison, May 2026), and only 50–60% of scheduled capacity comes online on time (Goldman Sachs Research, May 2026). A facility that already has power sidesteps all three. See brownfield vs greenfield data center cost per MW.
How much density can a legacy hall support after retrofit?
Legacy enterprise halls were built for 5–15 kW per rack, and air cooling tops out at roughly 30–50 kW per rack, while the common 2025–2026 design is hybrid, about 70% liquid and 30% air (StackedAI analysis, Cooling Solutions retrofit note, Aug 2026).
| Density tier | kW per rack | Cooling approach |
|---|---|---|
| Legacy enterprise hall | 5–15 | Air, raised floor or containment |
| Rear-door heat exchanger | 20–40 typical; up to 75 (Motivair) or 120 (OptiCool) | RDHx, entry about $17K per rack |
| Direct-to-chip | 60–130+ | Cold plates and CDUs, about $50–80K per rack; PUE toward ~1.15 |
| GB200 NVL72 | 120–130 | Direct-to-chip required |
| Single-phase immersion | 100–250 per tank | PUE 1.01–1.08 |
| Vera Rubin (estimate) | 190–230 | Direct-to-chip or immersion |
Sources: StackedAI analysis, Cooling Solutions retrofit note, Aug 2026; StackedAI analysis, density roadmap compiled from Goldman Sachs and Dell’Oro data, Aug 2026.
The liquid-cooled share of AI servers rose from 15% in 2024 to 54% in 2025 and is expected near 76% in 2026 (StackedAI analysis, density roadmap compiled from Goldman Sachs data, Aug 2026), so the design target is a hall where most load is liquid-cooled and air serves storage, networking, and lower-density tenants. Option-level costs and diligence flags are in liquid cooling retrofit cost for a legacy data center.
Why is power the binding constraint, not cooling?
Cooling vendors can deliver almost any density a buyer will pay for; power cannot be bought the same way. Median time from interconnection request to operation exceeded five years for projects built in 2025, and only 13% of 2000–2020 requests ever reached operation (LBNL, Queued Up: 2026 Edition, May 2026). More than 2.2 TW is waiting in US queues (RMI, Interconnection Reform for AI Data Centers, Mar 2026). CBRE reports AI-campus interconnection timelines of 24, 36, and 48 or more months (CBRE, 2026 US Real Estate Market Outlook: Data Centers, Jan 2026). Transformer lead times averaged 120 weeks in 2024, with 80–210 weeks for large units (Wood Mackenzie, Apr 2024), while US data center power demand is projected to grow from 31 GW in 2025 to 66 GW in 2027 (Goldman Sachs Research, May 2026).
A 7–25 MW facility with a service agreement, installed transformers, and a chilled-water plant is therefore a power position with a building attached. Water and electrical headroom, not the cooling vendor, decide the conversion (StackedAI analysis, Cooling Solutions retrofit note, Aug 2026), and speed-to-power through bridge gas, fuel cells, and legacy interconnects is where smaller operators beat hyperscalers (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026). The on-site power playbook is in energy-first campus development.
How do PE firms and family offices underwrite the returns?
StackedAI’s public framework (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026) rests on four rules.
- A 2.5–3.0x net MOIC floor and an 18–20% or higher IRR target. Anything lower does not compensate for single-asset execution risk.
- Returns compress with build size. The $12M per MW AI-ready build cost is the binding constraint: each added MW of fit-out is funded at the marginal cost of new plant, while the arbitrage sits in the sunk shell and interconnect.
- Two debt archetypes. With an anchor tenant, 60% debt and 40% equity at 7.5%; without one, 55/45 at 9%. Tenant sourcing runs in parallel with diligence.
- Exit on stabilized yield, not replacement cost.
Market debt terms support the archetypes: spreads in the low 200 basis points and up to 85% loan-to-cost for top credit, versus 200–300 basis points wider at 70–80% loan-to-cost for non-credit tenants (JLL, North America Data Centers market dynamics, Aug 2026). Tier-2 colocation pricing runs 15–30% below primary averages, partly offset by utility cost of about 7.15 cents per kWh in Dallas-Fort Worth against about 9.25 cents in Northern Virginia (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026). How equity, debt, and advisory pieces are documented is covered in data center transaction structures.
Why is the 7–25 MW lane uncontested by large-cap peers?
Because the fee does not cover a large firm’s process: bulge-bracket buy-side mandates begin at about $250M enterprise value; middle-market boutiques cover $50–250M; below $50M the field thins; below $25M it effectively disappears. A 1% retainer on a $20M acquisition is $200K (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026), too small for a bank’s deal team, adequate for a specialist who already knows the utility and the tenant pool.
Operators face the same arithmetic. About half of the independents known in 2021 had been acquired by 2026, the platforms that bought them now need 100 MW-plus campuses, and the states most thoroughly picked clean are South Carolina, Alabama, Colorado, Kansas, Arizona, and Idaho (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026). The lane is uncontested because it is the wrong size for the firms that have the capital, not because it is unattractive.
Which secondary markets fit the thesis?
Frontier markets account for 77% of North American capacity under development (JLL, North America Data Center Report Midyear 2026, Aug 2026), and 64% of US construction sat outside the traditional hubs at year-end 2025 (JLL via Bisnow, Feb 2026).
- Columbus. Vacancy of 0.1% despite new supply; fourth-ranked primary market globally (JLL, North America Data Center Report Midyear 2026, Aug 2026; Cushman & Wakefield, 2026 Global Data Center Market Comparison, May 2026).
- Dallas-Fort Worth. Delivered more than 2 GW in the first half of 2026, absorbed more, and ranks as the top market globally (JLL, Aug 2026; Cushman & Wakefield, May 2026).
- Austin and San Antonio. Completed 1.7 GW and absorbed 796 MW in the first half of 2026, leading the secondary-market ranking (JLL, Aug 2026; Cushman & Wakefield, May 2026).
- Atlanta. A record 918 MW absorbed in six months; vacancy 1.0% (JLL, Aug 2026; CBRE, Global Data Center Trends 2026, Jun 2026).
- Phoenix. 442 MW absorbed and 1.7 GW under construction (JLL, North America Data Center Report Midyear 2026, Aug 2026).
- Texas overall. 26 GW existing plus under construction against 13 GW in Virginia (JLL, Aug 2026; Cushman & Wakefield, Feb 2026). The August 3, 2026 pause on new data center development cut projected 2027 load growth from 14% to 6% (EIA, Short-Term Energy Outlook, Aug 2026), raising the value of already-energized Texas sites.
StackedAI overlays those metros with the states holding the densest remaining independent supply: Ohio, Nebraska, Nevada, Tennessee, and Oklahoma (StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026).
What are the main risks in a Tier-2 brownfield conversion?
- Interconnection. Directory MW and contracted MW are rarely the same number; service agreements and metered load are the diligence.
- Transformer and switchgear lead times. At 120 weeks average (Wood Mackenzie, Apr 2024), a conversion needing new medium-voltage gear misses a 12–18 month schedule unless gear is ordered before close.
- Water. Liquid cooling shifts the constraint to make-up water and chilled-water capacity; sites without a chilled-water plant carry capital cost and permitting risk.
- Structural. Racks at 100 kW and above exceed the floor loading of many raised-floor halls; slab-on-grade converts more easily.
- Policy. The Texas pause (EIA, Aug 2026), ComEd delays to 2032 and beyond, and Chicago’s 10-year letter-of-credit rule at 50 MW or more (CBRE, Feb 2026) show that policy can change a timeline overnight.
- Tenant credit. Without an anchor, the stack moves from 60/40 at 7.5% to 55/45 at 9% (StackedAI analysis, Aug 2026); see NNN data center lease scarcity on why enterprise-credit leases are scarce.
Key terms
- Brownfield conversion: the retrofit of an existing, previously developed facility for a new use, as opposed to greenfield construction on undeveloped land.
- Tier-2 market: a secondary metropolitan data center market outside the primary hubs; distinct from Uptime Institute Tier II, a facility classification denoting redundant capacity components with a single distribution path.
- Critical IT load: the power available to IT equipment after mechanical and electrical overhead, expressed in MW; the basis on which cost per MW is quoted.
- Powered shell: a building with structure, site work, and utility power, but no mechanical and electrical fit-out.
- PUE (power usage effectiveness): total facility energy divided by IT energy; lower means more of the feed reaches sellable IT load.
- MOIC (multiple on invested capital): total cash returned divided by total cash invested, net of fees and carry when described as net MOIC.
How StackedAI applies this
StackedAI sources 7–25 MW enterprise-owned and commercial data centers in secondary US markets for private equity sponsors and family offices, and screens each site against the buy box above before any engineering spend. Diligence starts with the utility service agreement and metered load, then chilled-water and electrical headroom, and only then cooling design. Andre van Zijl, StackedAI’s founder, spent more than 21 years operating colocation and enterprise infrastructure. Engagement models are on the advisory services page.
Frequently asked questions
What does it cost to convert a legacy data center to AI-ready colocation?
StackedAI benchmarks an AI-ready, liquid-cooled brownfield conversion at about $12M per MW of critical IT load, against a Tier-3 baseline of $7–9M per MW and greenfield at $17.6M per MW (Cushman & Wakefield, 2026 Development Cost Guide). Liquid cooling alone runs $2–3M per MW. Figures vary by market; StackedAI benchmarks these per engagement.
How long does a brownfield conversion take compared with greenfield?
A retrofit of an energized legacy facility typically takes 12–18 months, versus 36 or more months for greenfield (StackedAI analysis). The difference is power: new large-load requests average 4.4 years (Cushman & Wakefield) and LBNL reports median interconnection above five years. An existing interconnect removes most of that wait.
Why are 7–25 MW facilities mispriced?
Enterprise-owned data centers sit inside non-data-center companies, carried as property and equipment, and rarely appear in facility directories. Below $50M the advisory field thins and below $25M it effectively disappears, so few sophisticated buyers compete. With North American vacancy at 1% for three years (JLL), energized capacity has scarcity value once surfaced.
What returns do PE firms and family offices target on these conversions?
StackedAI’s public underwriting framework uses a 2.5–3.0x net MOIC floor and 18–20% or higher IRR targets. Returns compress as build size grows because the $12M per MW AI-ready cost is the binding constraint. The capital stack is 60/40 debt-to-equity at 7.5% with an anchor tenant, or 55/45 at 9% without.
What are the biggest risks in a Tier-2 brownfield conversion?
Power first: utility interconnection, transformer lead times averaging 120 weeks (Wood Mackenzie), and policy shocks such as the August 2026 Texas pause on new data center development. Water for liquid cooling, floor loading for heavier racks, and the gap between nameplate capacity and contracted load follow. Cooling technology is rarely the constraint.
Sources
- JLL, North America Data Center Report Midyear 2026, Aug 2026, https://www.jll.com/en-us/newsroom/data-center-demand-exceeds-expectations-in-h1-2026
- JLL, North America Data Centers market dynamics, Aug 2026, https://www.jll.com/en-us/insights/market-dynamics/north-america-data-centers
- JLL, 2026 Global Data Center Outlook, Jan 2026, https://www.jll.com/en-us/insights/market-outlook/data-center-outlook
- JLL via Bisnow, Data Center Vacancy at Record Low as Supply Pipeline Slows, Feb 2026, https://www.bisnow.com/national/news/data-center/data-center-vacancy-at-record-low-as-supply-pipeline-slows-133417
- CBRE, North America Data Center Trends H2 2025, Feb 2026, https://www.cbre.com/insights/books/north-america-data-center-trends-h2-2025
- CBRE, Global Data Center Trends 2026, Jun 2026, https://www.cbre.com/insights/reports/global-data-center-trends-2026
- CBRE, 2026 US Real Estate Market Outlook: Data Centers, Jan 2026, https://www.cbre.com/insights/books/us-real-estate-market-outlook-2026/data-centers
- CBRE, North America Data Center Trends H2 2025, Chicago profile, Feb 2026, https://www.cbre.com/insights/books/north-america-data-center-trends-h2-2025/chicago-data-center-market
- CBRE investor survey via Bisnow, Data Center Asset Sales Slump Even as New Development Booms, Aug 2025, https://www.bisnow.com/national/news/data-center/untapped-opportunity-data-center-asset-sales-slump-even-as-new-development-booms-130597
- Cushman & Wakefield, 2026 Data Center Development Cost Guide, Aug 2026, https://www.cushmanwakefield.com/en/united-states/insights/data-center-development-cost-guide
- Cushman & Wakefield, Americas Data Center Market Shifts to Managed Growth (press release), Feb 2026, https://www.cushmanwakefield.com/en/united-states/news/2026/02/americas-data-center-market-shifts-to-managed-growth
- Cushman & Wakefield, 2026 Global Data Center Market Comparison, May 2026, https://ir.cushmanwakefield.com/news/press-release-details/2026/Dallas-Texas-Ranked-No–1-Primary-Data-Market-in-the-World-as-AI-Demand-Power-Constraints-and-Regulation-Reshape-CRE-Strategy/default.aspx
- Goldman Sachs Research, US Data Center Power Demand Projected to Double by 2027, May 2026, https://www.goldmansachs.com/insights/articles/us-data-center-power-demand-projected-to-double-by-2027
- LBNL, Queued Up: 2026 Edition, May 2026, https://emp.lbl.gov/publications/queued-2026-edition-characteristics
- RMI, Interconnection Reform for AI Data Centers and Generator Queues, Mar 2026, https://rmi.org/resources/interconnection-reform-ai-data-centers-generator-queues/
- Wood Mackenzie, Supply Shortages and an Inflexible Market Give Rise to High Power Transformer Lead Times, Apr 2024, https://www.woodmac.com/news/opinion/supply-shortages-and-an-inflexible-market-give-rise-to-high-power-transformer-lead-times/
- EIA, Short-Term Energy Outlook, Aug 2026, https://www.eia.gov/outlooks/steo/
- TeraWulf, Expands Strategic Partnership with Fluidstack Through New 168 MW AI Compute Joint Venture (press release), Oct 2025, https://investors.terawulf.com/news-events/press-releases/detail/121/terawulf-expands-strategic-partnership-with-fluidstack-through-new-168-mw-ai-compute-joint-venture
- Data Center Knowledge, Neocloud Storm Gathers as Data Center Deals Stall Over Credit Risk, Apr 2026, https://www.datacenterknowledge.com/cloud/neocloud-storm-gathers-as-data-center-deals-stall-over-credit-risk
- StackedAI analysis, Tier-2 brownfield conversion underwriting framework, Aug 2026
- StackedAI analysis, Cooling Solutions retrofit note, Aug 2026
- StackedAI analysis, density roadmap compiled from Goldman Sachs and Dell’Oro data, Aug 2026
- StackedAI analysis, transaction-structures framework, Aug 2026