Industrial Outdoor Storage: How to Underwrite Dirt That Rents Like a Building

Introduction

Industrial outdoor storage — truck and trailer yards, container storage, contractor and equipment yards, material laydown — is the fastest-growing corner of industrial real estate, and almost everything written about it is written by brokers selling portfolios to funds. The institutional case is easy to state: infill industrial dirt cannot be re-entitled, tenants are sticky, and ongoing capex is close to nothing.

All of that is true. It is also not an underwriting method. Two things decide whether a small IOS deal works, and neither appears in the sector reports: what the entitlement actually permits, and what it costs to turn raw dirt into a yard anyone will rent.

TL;DR: In IOS you are buying zoning, not improvements. Grade the entitlement first — a legal non-conforming yard that sits vacant too long can lose the right to exist, and most ordinances say so explicitly. Then add site work to your basis before you compute a yield, because ungraded, unfenced, undrained land is not an IOS asset, it is land.

What IOS is, and what it is not

An IOS property is a fenced, surfaced yard where the improvements are ancillary. There is usually a small office or shop building — often under 10% of site area — and the rent is being paid for the ground. Tenants are trucking and logistics companies, container lessors, contractors, equipment rental firms, utility and municipal fleets, and increasingly last-mile operators who need trailer parking they cannot get at a modern distribution centre.

It is not a warehouse with a yard attached. If the building is the revenue and the yard is the parking, you are underwriting industrial, and the industrial infill viability framework applies instead. IOS is the reverse: the dirt is the revenue.

The scarcity argument is genuine. Very few jurisdictions still zone new land for outdoor storage, most of the existing supply sits on infill parcels that would never be approved today, and higher-value warehouse development has consumed a large share of the sites that could have converted. Supply is fixed by ordinance rather than by construction cost, which is a much harder constraint.

Grade the entitlement before anything else

This is where the thesis and the risk are the same fact. The reason IOS dirt is valuable is that it cannot be replicated — and if the reason it cannot be replicated is that your particular yard is grandfathered, then the right you are buying is fragile in ways a warehouse never is.

Most zoning ordinances treat a legal non-conforming use as a right that survives only while it continues. Two clauses matter, and they are in the ordinance text, not the title report:

• Discontinuance. If the use stops for a defined period — commonly six to twelve months — the non-conforming right terminates permanently and the property reverts to what current zoning allows. A vacant yard is not a value-add opportunity in that case. It is an expired one.
• Destruction. Many ordinances end the right if the improvements are damaged beyond some threshold, frequently 50% of value. On a yard where the improvements are a fence and a shop, that threshold is easier to cross than it sounds.

Grade every deal before you underwrite it:

Entitlement status	Can you expand the use?	Rebuild after casualty?	Lender appetite	Grade
Permitted by right under current zoning	Yes	Yes	Bank, bridge, some CMBS	A
Conditional or special use permit, current and transferable	With a new hearing	Usually, if the permit survives	Bank, after permit review	B
Legal non-conforming, currently occupied	No	Often not	Recourse bank only	C
Legal non-conforming, currently vacant	No	Often not	Cash, or recourse at low leverage	D
No record of a permitted use	No	No	None	F

Anything below a B needs a zoning verification letter from the jurisdiction, in writing, naming the property and the use, before the contingency expires. A broker's assurance that "it has always been a truck yard" is not a verification letter, and a phone call to a planner is not either.

What it costs to make dirt rentable

The other half of the sector reports that does not survive contact is the low-capex claim. It is true of ongoing capex — a yard has no roof, no HVAC and no tenant improvements — and misleading about entry capex.

Raw land does not rent as IOS. Before a tenant will pay, the site generally needs clearing and grubbing, cut and fill to a workable grade, a compacted aggregate base or millings surface capable of carrying loaded trailers, perimeter fencing at six to eight feet with a gate and access control, site lighting, and drainage that satisfies the jurisdiction. Depending on topography, existing surface and how much stormwater work is required, that is a wide range — commonly a low-to-mid six-figure number per acre in the markets where IOS is worth doing.

Here is why it changes the answer. Take five acres of M-2 dirt at $200,000 an acre — a $1,000,000 purchase. Assume $150,000 an acre in site work, so $750,000 more. Your basis is $1,750,000, not $1,000,000. If the finished yard rents at $3,500 per acre per month, gross rent is $210,000 a year, and at a 15% expense ratio the NOI is about $178,500.

Against the land alone that is a 17.9% yield, and it is the number a seller will show you. Against the real basis it is 10.2%. Both are arithmetic. Only one of them is the deal. (Those inputs are illustrative — substitute your own market's land basis, site work bids and achieved yard rents. The point is the structure, not the figures.)

A stabilised, already-improved yard removes this problem and prices accordingly. The spread between a raw parcel and a finished one is roughly the site work plus a developer's margin, and if it is not, one of the two is mispriced.

Stormwater is the trigger nobody prices

Improving a yard changes how water leaves it, and that is what pulls a jurisdiction into the project.

Paving a site converts it to impervious surface, which triggers detention or retention requirements sized to a design storm — commonly the 10-, 25- or 100-year event depending on the ordinance. Detention infrastructure is expensive, consumes acreage that cannot be rented, and is engineered rather than estimated.

The nuance that catches people: compacted gravel is frequently counted as impervious. Buyers assume an aggregate surface avoids the requirement, and in many jurisdictions it does not, because the calculation is based on runoff coefficient rather than material.

Separately, an operating yard may fall under an industrial stormwater discharge permit. That is not a construction permit that goes away when the work is done — it is an ongoing obligation with a site plan, sampling and reporting, and it belongs in operating expenses.

Get a civil engineer on the site during diligence. This is the single line item most likely to move by six figures between your offer and your first tenant.

Environmental exposure

Land that has held trucks, equipment, containers or materials for forty years has usually held petroleum, hydraulic fluid and solvents as well.

A Phase I environmental site assessment is standard and any lender will require it. On IOS, budget for the Phase I to identify recognised environmental conditions and to recommend a Phase II — subsurface sampling — more often than it would on other property types. Historical aerial photography and Sanborn maps matter here, because the relevant activity happened outdoors and left no building to inspect. Ask directly about former underground or aboveground fuel tanks, wash bays and maintenance areas, and about whether the site was ever a salvage yard.

The remediation exposure on a five-acre yard can exceed the equity in the deal. Do not waive this contingency to win a bid.

Leases and tenants

IOS leases are shorter than warehouse leases — one to five years is typical, with three common — and that cuts both ways. Rents reset toward market quickly, which has been an advantage while yard rents have been rising. It also means the rent roll offers little protection in a downturn, and a single tenant occupying an entire yard is closer to a credit position than a diversified income stream.

Underwrite the tenant as a business, not as a covenant. Most IOS tenants are private operating companies without rated credit. Ask for financials, and understand what the yard does for them: a tenant whose yard sits next to their terminal is far stickier than one storing containers that could sit anywhere within thirty miles.

Watch the use clause. A yard permitted for trailer parking is not necessarily permitted for container stacking, equipment repair or material processing, and a tenant who quietly expands the use can jeopardise a non-conforming right you are relying on.

Financing

Deal sizes in this sector suit regional and community banks, which is one of its genuine advantages for a smaller buyer. Expect recourse, 60% to 70% loan to value, and shorter terms than agency debt on residential product.

Two things complicate it. Appraisers see relatively few IOS comparables, and an appraisal that treats a stabilised yard as raw land will undercut your proceeds. And lenders read the entitlement grade the same way you should — a C or D grade property may finance only at low leverage with full recourse, because the collateral's value depends on a use that could lapse.

Bridge and private credit will lend on the improvement plan, at a cost that assumes you execute it on schedule.

What kills deals

1. A non-conforming use that has already lapsed. The yard has been vacant fourteen months and the ordinance terminates the right at twelve. There is no remedy after closing.
2. Site work priced from a rule of thumb. Grading, base and drainage are engineered numbers. Get bids, not a per-acre assumption.
3. Stormwater discovered after the offer. Detention consumes rentable acreage and capital simultaneously.
4. Environmental history. A Phase II finding on a former fuelling or maintenance area.
5. Yield computed on land basis rather than all-in basis. The most common way a raw IOS parcel looks better than it is.
6. A use clause the tenant has outgrown. Silent expansion into a use the entitlement does not cover.
7. Access. A yard that cannot be entered and exited by a loaded 53-foot trailer without crossing someone else's property is worth materially less, and turning radii and street geometry are the reason.

Run the standard due diligence checklist alongside all of this — the zoning, civil and environmental work sits on top of it, not instead of it.

FAQ

How much land do you need for a viable yard?

Two to three acres is generally the floor for a leasable IOS site, and five to fifteen acres is where most single-tenant demand sits. Smaller parcels work as contractor yards but reach a much smaller tenant pool.

Is IOS really low maintenance?

Ongoing, yes — grading touch-ups, fence and gate repair, lighting, snow or dust control, and periodic surface replenishment. There is no roof and no tenant improvement allowance. The capital intensity is concentrated at the front, not spread across the hold.

Gravel or asphalt?

Gravel or millings cost far less and are usually enough for trailer storage; asphalt or concrete is needed where containers are stacked or where loads are heavy and concentrated. The stormwater treatment of each in your jurisdiction should be part of the decision, not an afterthought.

Can I convert vacant industrial land into IOS?

Only if the current zoning permits outdoor storage by right or by conditional permit. You cannot recreate a grandfathered right, and if a jurisdiction was willing to entitle new outdoor storage, the scarcity argument that makes IOS attractive would not hold there in the first place.

How does IOS compare with other niche classes?

A single-tenant ground-leased yard is one of the lowest-burden commercial assets available, and a multi-tenant yard with a gate and short leases is meaningfully more work. Both sit well below operating businesses like RV parks or marinas on the operational burden scale. See also the wider survey of income uses for vacant land, where truck parking is one option among several.

Conclusion

IOS earns its returns from a supply constraint written into zoning ordinances rather than into construction costs, and that is a durable place for a constraint to live. But it means the ordinance is the asset. Read it, get the use verified in writing, and know exactly what happens to your rights if the yard empties or burns.

Then put the site work in the basis. The gap between a yield on land and a yield on an operating yard is the entire difference between a deal that pencils and one that only appeared to.

Buy the entitlement. The dirt comes with it.

Sources

• Northmarq, Comprehensive Guide to Industrial Outdoor Storage.
• Colliers and CenterCap Group sector commentary on IOS supply and institutional capital flows.
• U.S. EPA, Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activity.
• ASTM E1527-21, Standard Practice for Phase I Environmental Site Assessments.
• Municipal zoning ordinance provisions on discontinuance and destruction of legal non-conforming uses (verify text locally; thresholds vary).