Self storage feasibility studies

A self storage feasibility study is the analysis that tests whether a proposed store can let enough space, at a high enough rate, to justify what it will cost to build and to repay the debt behind it. It sits between the idea and the commitment: before the land is bought, before the design is fixed, and before any lender is approached. Done properly, it is the document that stops a weak site early and gives a strong site the evidence it needs to raise finance.

The UK market makes the discipline worthwhile. The SSA UK and Cushman & Wakefield 2026 annual report counts 3,143 stores and 67.5 million square feet of space nationally, yet supply per person remains a fraction of mature markets, so genuinely under-served catchments still exist alongside towns that are already crowded. This guide covers what a credible study contains, from catchment demand and competitor supply through rate assumptions and occupancy build-up to the development appraisal, and what lenders expect to see before they fund a scheme.

What is a self storage feasibility study?

A feasibility study is an evidence-based assessment of a specific site for a specific storage concept. It answers four questions in sequence: how much demand exists in the catchment, how much competing supply serves it, what rate and occupancy the proposed store can realistically achieve, and whether the resulting cash flow supports the cost of building and financing it. The output is a recommendation, sometimes a clear no, with the assumptions laid out so they can be challenged.

Studies range from a desktop market screen, useful for filtering a shortlist of sites cheaply, to a full study with site visits, mystery shopping of competitors and a complete financial model. For a project that will carry development debt, the full version is the relevant one, and independence matters: a study commissioned from a consultant with no stake in the land deal carries far more weight with funders than the developer's own spreadsheet. The cost of a proper study is trivial against the cost of building the wrong store.

How do you define the catchment area for a storage site?

Self storage is a convenience purchase, so the catchment is defined by drive time rather than distance. Most UK analysis works on a 15 to 20 minute drive time around the site, tightened in dense urban areas where customers travel less and widened in rural ones where they expect to travel further. Within that boundary the study counts population and households, then looks at the characteristics that correlate with storage use: housing turnover, the share of flats and smaller homes, household income, and the density of small businesses that rent units for stock and tools.

The shape of the catchment matters as much as its size. Rivers, railway lines and congested junctions cut effective catchments in ways a circle on a map does not show, and a site on the wrong side of a barrier can lose half its theoretical population. Visibility and daily traffic past the site add demand that pure residence counts miss, which is why prominent main-road sites consistently outperform hidden industrial estate plots with identical demographics.

How do you audit competing storage supply?

The supply audit lists every existing store serving the same catchment, its lettable area, formats and pricing, plus any pipeline schemes in the planning system, since a store that opens two years after yours still shapes your stabilised occupancy. Dividing total supply by catchment population gives square feet per person, the standard saturation measure. The SSA UK and Cushman & Wakefield figure for the UK as a whole was 0.94 square feet per person in the 2025 report, against around 7 square feet per person in the United States on Savills commentary, so national headroom is real, but individual towns can still be oversupplied.

Quality beats arithmetic here. Mystery shopping reveals what desktop research cannot: actual quoted rates rather than website teaser prices, promotional discounting, waiting lists for popular unit sizes, and how full competitors really are. A catchment where every competitor is full and quoting firm prices supports a new store even at decent supply per capita; a market where operators are discounting heavily to hold occupancy is a warning regardless of what the ratio says.

How should you set rental rate assumptions?

Rate assumptions should be built from the local evidence gathered in the supply audit, not from national averages. The SSA UK and Cushman & Wakefield 2026 report records average annual revenue of 27.40 pounds per square foot excluding VAT across UK stores, which is a useful sanity check, but achieved rates vary enormously between a London multi-storey store and a rural container yard, and a study that simply imports the national figure has not done the work.

The model should distinguish headline rates from net achieved rates after introductory offers and discounting, because the gap between the two is where optimistic appraisals quietly fail. Rates also vary by unit size, with smaller storage units earning more per square foot, so the assumed unit mix drives revenue as much as the assumed rate. A disciplined study prices each band of unit sizes against named local comparables, applies a discount for the new entrant's lease-up period, and only then projects growth, modestly, in later years.

How do you model occupancy build-up for a new store?

A new self storage facility opens empty and fills gradually, and the speed of that fill determines how long the project burns cash. UK experience is that stores typically take three to five years to stabilise. The SSA UK and Cushman & Wakefield 2026 report puts average occupancy across all UK stores at 74.5 percent, with mature stores at 79.6 percent, and those figures frame what a sensible model assumes at stabilisation: projecting 95 percent occupancy from year two is a red flag any experienced reader will catch.

A credible build-up curve starts with the monthly net move-ins the catchment can plausibly deliver, ramps occupancy over 36 to 60 months, and pairs the curve with the phased fit-out plan, since occupancy is measured against the space actually fitted out. The model then needs an operating cost line that does not shrink with vacancy, because staff, rates, utilities, insurance and marketing run at close to full cost from the day the store opens. The result is a clear picture of peak cash requirement, which is precisely the number the funding has to cover.

What goes into the development appraisal?

The development appraisal joins the revenue model to the cost side. Costs comprise the land, construction at realistic benchmarks, with PSL Limited's February 2026 data putting core build plus fit-out at 550 to 850 pounds per square metre excluding land and professional fees, plus those fees, planning costs, finance interest during the build and lease-up, a contingency, and the working capital to fund operating losses until the store breaks even. Against that sit the projected cash flows and the stabilised value of the trading business.

The appraisal should be stress-tested, not just stated. Sensible sensitivities include rates 10 percent below assumption, lease-up a year slower, construction cost overrun and higher interest rates, run individually and in combination. If the project only works in the base case, it does not work. The appraisal also frames the funding ask: how much debt the cash flows can support, how much equity the developer must contribute, and what the refinance looks like once the store stabilises. This is the document around which we structure development finance conversations.

What do lenders expect a feasibility study to show?

Lenders funding a storage development are underwriting a forecast, so they scrutinise the feasibility evidence as hard as the build contract. They expect an independent author with sector experience, a defined drive-time catchment with sourced demographics, a complete competitor audit with verified rates, and occupancy and rate assumptions that sit defensibly against published benchmarks such as the SSA UK and Cushman & Wakefield annual report. They expect the downside cases to be shown, not hidden, and the working capital reserve to be funded within the facility rather than assumed away.

They also read the study for operator credibility: who will run the store, on what management platform, with what marketing plan, and whether the team has done it before. In our experience the projects that secure the best terms are those where the feasibility study, the cost plan and the funding request tell one consistent story. We help developers present that package, and because we know which lenders are actively backing storage schemes, we put it in front of funders who already understand what a lease-up curve looks like rather than those who need the sector explained from scratch.