This 21ft x 8ft custom office cabin is a fully refurbished anti-vandal steel portable building in Graphite Grey, professionally restored inside and out before dispatch. It shares the same footprint as our 21ft canteen cabin but is configured specifically as a dedicated office workspace — no kitchenette is fitted, maximising the open-plan floor area for desks, storage, or meeting configurations. The key distinction of this unit is its built-in air conditioning system, providing both heating and cooling for year-round climate control without reliance on a separate wall-mounted heater or external unit.The entry door is a fully glazed white UPVC lockable door with keys — a significant aesthetic upgrade over a standard steel personnel door, giving the unit a cleaner, more contemporary front elevation suited to home office installations, garden workspaces, and client-facing business environments. Three 900mm × 900mm sliding windows provide natural light and ventilation across the interior. Note that these windows are not fitted with anti-vandal shutters — if the unit is to be deployed on an active construction site or in a high-security location, the 21ft Office & Canteen Cabin with AV-shuttered windows may be a more appropriate choice.The electrical fit-out includes an internal consumer unit with external isolator, six double electrical sockets, and three LED panel lights controlled via a wall switch — one socket more than the canteen cabin variant, providing additional power capacity for monitors, printers, and peripheral equipment. Flooring is new Silver Oak HB vinyl throughout — hardwearing, easy to clean, and consistent with the Graphite Grey exterior finish in tone and style.The unit is wired and ready for mains electrical connection — an external mains supply must be connected on site by a licensed electrician before the air conditioning, lighting, and sockets are operational. For guidance on temporary structure siting and permit requirements in the USA, refer to the International Code Council building standards reference.21ft x 8ft Custom Office Cabin — DimensionsDimensionImperialMetricExternal Length21ft6,400mmExternal Width8ft2,440mmExternal Height8ft 6in2,590mmInternal Length (est.)approx. 20ft 4inapprox. 6,200mmInternal Width (est.)approx. 7ft 4inapprox. 2,240mm21ft Custom Office Cabin — Fit-Out SpecificationItemSpecificationConstructionHeavy-duty anti-vandal steel shellExterior FinishGraphite Grey professional-grade paintEntry Door1 × fully glazed white UPVC lockable door with keysWindows3 × 900mm × 900mm sliding windows — no AV shuttersFlooringNew Silver Oak HB vinyl — hardwearing, easy to cleanClimate ControlAir conditioning — heating and cooling, all-seasonLighting3 × LED panel lights on wall switchPower Sockets6 × double electrical socketsElectrical SystemInternal consumer unit with external isolatorStandard Inclusions — 21ft x 8ft Custom Office CabinHeavy-duty anti-vandal steel shell — fully refurbished inside and outGraphite Grey professional-grade exterior paint1 × fully glazed white UPVC lockable entry door with keys3 × 900mm × 900mm sliding windowsNew Silver Oak HB vinyl flooring throughoutAir conditioning system — heating and cooling3 × LED panel lights on wall switch6 × double electrical socketsInternal consumer unit with external isolatorWhat’s Not IncludedExternal mains electricity supply connectionSite preparation, levelling, or foundation worksCrane or lifting equipmentFurniture, desks, or office equipmentKitchenette or plumbing facilitiesAnti-vandal window shutters — see 21ft Office & Canteen Cabin if requiredLocal authority permitsBest Use Cases for a 21ft x 8ft Custom Office CabinHome garden office and remote work studioConstruction or project site management officeSmall business administration or retail unitPortable classroom or tutoring studioTemporary administration office for events or hospitality sitesArtist, photography, or creative studio spaceAlso available: 21ft x 8ft Office & Canteen Cabin with Kitchenette, 24ft x 9ft Portable Site Office, and 32ft x 10ft Open Plan Portable Office Cabin.Every unit is inspected by JK Shipping LLC prior to dispatch.