Shipping Container Office

Commercial space planning allots 4–6 m² per open-plan workstation (desk, chair, circulation share). The arithmetic is direct: 13.9 m² ÷ 4–6 m² = 2–3 workstations in a 20 ft; 28.3 m² ÷ 4–6 m² = 4–7, in practice 4–6 workstations in a 40 ft once a meeting corner takes a bay.

The 2.35 m width (≈2.2 m after lining) dictates the furniture plan: desks run along one long wall, leaving a 1.4 m circulation strip — two desk rows facing each other do not fit with code-friendly circulation. In a 20 ft: two 1.4–1.6 m desks along a wall plus a printer/storage bay at the closed end, or three desks at 1.2 m pitch for tighter teams. In a 40 ft: four desks in the first 7 m, then a partition, then a 2.4–3 m meeting corner seating four — or an office pair at the closed end for calls. Glazing the cargo-door end (the one big opening that needs no structural cutting) transforms the far half from corridor-dark to usable.

The standard office package, whether factory-fitted or DIY: a steel personnel door (915 × 2,030 mm) so nobody operates cargo doors daily; two to four windows (~900 × 1,200 mm, aluminium, security-shuttered on jobsites); and an electrical package — 50–100 A sub-panel, 6–10 duplex outlets, LED battens, data conduit, exterior inlet for shore power or generator. Every cut opening gets a welded steel frame, because the corrugated wall is structural (the framing rules are the same as for container homes).

Placement notes that cost nothing at build time: put the personnel door in the side wall near one end (preserving the end wall for glazing), put window heads at 2.0 m for daylight depth, and run all wiring in surface conduit or the insulation zone — never loose against bare steel, where condensation lives.

Budget the package realistically: personnel door supplied and framed $800–1,500, each window $300–700 fitted, the electrical package $1,500–4,000 depending on circuits and whether an electrician signs it off. With cutting and steel framing included, the openings-plus-electrics stage runs $4,000–8,000 on a 20 ft — typically the largest line after insulation and HVAC.

Bare steel makes the worst office envelope on the market: it conducts ~1,500× better than timber, so summer sun drives an unshaded closed box to 50–60 °C inside, and one worked winter day condenses breath and kettle steam onto every cold surface. The working spec is 50–75 mm of closed-cell spray foam (R-12 to R-21) on walls and ceiling with lining over — about $1,500–3,000 for a 20 ft — full options and R-values in the insulation guide.

Sizing the conditioning: an insulated 20 ft needs a 9,000–12,000 BTU (2.6–3.5 kW) mini-split ($700–1,500 installed on the end wall); a 40 ft needs 18,000–24,000 BTU or two smaller heads. Add trickle ventilation — occupied sealed boxes need fresh air at ~7–10 L/s per person, met by a wall-mounted HRV or simply vents plus the mini-split’s fan; the physics of why is in the ventilation guide.

The jobsite configuration plays to the container’s native strengths: it arrives on a tilt-bed, works for the project duration on cribbing or a gravel pad, then leaves for the next site — a security safe and an office in one steel shell, typically with barred windows, a lockbox on the door and half the box left as tool storage behind a partition. Under construction-trailer rules, most jurisdictions treat it as temporary equipment: minimal or no permitting.

A permanent backyard or business office crosses a regulatory line: fixed placement usually makes it an accessory structure needing a permit, setback compliance, anchoring, and inspected electrics (rules and typical thresholds are similar to those in the container home guide — occupancy is what regulators care about). Build-wise, permanence argues for the high cube, real foundation piers (foundation guide), upgraded glazing and a mains feed rather than a generator inlet.

The rent-vs-buy arithmetic mirrors the storage market: a purchased container office breaks even against trailer rental in roughly 2–4 years, holds scrap-plus value indefinitely, and is dramatically more theft-resistant on open sites. The trailer wins on interior width (3.0–3.6 m) and on arriving with HVAC and finishes as standard. Shell prices by grade are in the prices guide — for an office, wind-and-water-tight is the value grade; the money belongs in insulation, not paint.