Calculator
How much does it cost to build storage units?
Any single number is a guess, because the answer depends entirely on the route in. Set your unit count and route below for a sourced range — with the assumptions on show, and an honest “no benchmark exists” where that is the truthful answer.
This is the input that moves the answer most. UK demand skews small — around 35% of customers take 11–50 sq ft — so the average unit is well below the US 100 sq ft default.
Estimated cost
£749,000 – £1.19m
Indicative range — not a quote · VAT basis not stated
- Construction & fit-out
- £375,000 – £477,000
- Land & professional fees
- £374,000 – £713,000
- Cost per unit
- £7,490 – £11,900
- Lettable area
- 5,500 sq ft
- Building size (gross)
- 7,333 sq ft
What it earns back — indicative
- Licence-fee income a year
- £120,000
- Rough payback
- 6.2–9.9 years
£27.40 per sq ft a year ex VAT is the headline average revenue per sq ft in the SSA UK / Cushman & Wakefield 2026 Annual Industry Report, and 79.6% is its mature-store occupancy, applied to lettable area rather than gross. The two come from different mixes of stores, so treat the result as indicative. Gross income only: before operating costs, financing, and the leaner fill-up years. Revenue per sq ft fell 5.1% year on year, so stress-test any appraisal below the average.
- Grossed up to a whole-project total using the published budget split — 25–40% land, 40–50% hard construction, 10–20% soft costs (professional fees, surveys, planning, contingency). A plan with no soft-cost line is missing a tenth to a fifth of its true total.
01 / At a glance
The same sums at the sizes people actually ask about, on the calculator's default assumptions — a 55 sq ft average unit, 75% of the building lettable, land and professional fees included in the new-build column.
| Units | Lettable area | Container site | Conversion (overall investment) | New build (all-in) |
|---|---|---|---|---|
| 10 units | Lettable area550 sq ft | Container site£15,500+ of stock | Conversion (overall investment)No published benchmark | New build (all-in)£74,900 – £119,000 |
| 50 units | Lettable area2,750 sq ft | Container site£77,500+ of stock | Conversion (overall investment)No published benchmark | New build (all-in)£375,000 – £596,000 |
| 100 units | Lettable area5,500 sq ft | Container site£155,000+ of stock | Conversion (overall investment)£250,000 – £750,000 | New build (all-in)£749,000 – £1.19m |
| 200 units | Lettable area11,000 sq ft | Container site£310,000+ of stock | Conversion (overall investment)£750,000 – £1.5m | New build (all-in)£1.5m – £2.38m |
New-build figures for schemes under about 5,000 sq ft gross (the 10- and 50-unit rows) extend a per-m² rate to a size it does not describe: at this scale a per-m² rate understates the real total, because planning, access, services and a reception are near-fixed costs, so read them as scale, not as a quote.
Container prices are ex VAT (CS Containers prints “+ VAT”). PSL’s and Kuboid’s pages do not say whether their figures include VAT, so confirm the basis on any quote. The container column is stock only at published from-prices — site works are quote-only. “No published benchmark” is not a gap in the calculator: it means the UK sources genuinely do not cover a scheme that small on that route, and inventing a figure would be worse than saying so.
02 / How the sum works
Your unit count and average unit size give the lettable area. Dividing by the net-to-gross ratio (75% by default — corridors, stairs and lifts are not lettable) gives the size of the building you actually have to pay for. From there each route uses the basis its own source publishes, and they are deliberately not the same basis:
- New build multiplies the building area by a published rate per m².
- Conversion reads off a published overall-investment band for the facility size. It does not derive a rate per m², because we found no published UK rate for one.
- Container multiplies your container count by a published from-price, and stops. Site works vary so much with site condition that quotes are the only real numbers.
The full methodology, the worked example behind it and the trade-offs between the three routes are in our guide to what it costs to build self storage. If you are still deciding whether to build at all, the full guide to starting a storage business covers site selection, planning and the day-one numbers.
Sources
- PSL Limited — self storage construction costs · as of February 2026
£550–£700/m² single-storey, £700–£850/m² multi-storey; the 25–40 / 40–50 / 10–20 budget split.
- Kuboid — cost to fit out a facility · as of December 2024
Overall-investment bands by facility size, and the premises purchase brackets.
- CS Containers — container price guide · as of 2026
Published from-prices for used and new one-trip 20ft and 40ft containers, ex VAT.
- SSA UK / Cushman & Wakefield Annual Industry Report · as of 2026
£27.40 per sq ft annual revenue ex VAT; 74.5% occupancy across the stores in its survey, 79.6% at its mature stores.
Figures are indicative estimates for planning, not a quote, and not advice. Costs move with site condition, region and specification — get quotes before committing.
03 / Common questions
Built it? now fill it · UK-based support · guided migration
The building is the easy half.
StoreBay helps operators fill more units, put billing and collections on autopilot, and run every site from one place.