Quick Answer: A mobile classroom container portable school Ontario build starts with a 40ft High Cube one-trip shell, then layers spray-foam insulation, ESA-certified electrical, ducted heating and cooling, a heat-recovery ventilator, an accessibility ramp, and double-pane windows. Expect a turnkey single-room layout sized for 20 to 28 students, with the final number driven by insulation depth, HVAC and HRV spec, electrical service size, and fit-out level. Real lead times and COD-honest quotes, priced to your specific address: call us at 519-754-6844. 30+ years operating, 4.9 stars on 124+ Google reviews, 1-3 day delivery Ontario-wide from our Brantford yards.
In This Guide
- Why is the 40ft High Cube the right classroom shell?
- How do you prep a cargo box for kid-grade duty?
- How do you insulate a container classroom for a Brantford winter?
- How much electrical service does a 28-student classroom need?
- How do you size HVAC and ventilation to ASHRAE 62.1?
- What windows and doors does a container classroom need?
- How do you make a container classroom accessible?
- What goes into the classroom fit-out?
- How is a container classroom sited and delivered?
- What do schools actually budget, and how long does it take?
- Frequently asked questions
Reading time: about 14 minutes.
Why is the 40ft High Cube the right classroom shell?
The 40ft High Cube is the right classroom shell because it gives a full-size room without permanent-construction cost or schedule. Its external footprint is 12.19 m by 2.44 m, and the net usable floor after insulation is roughly 27 m². That seats a real Ontario class of twenty-plus students under one truckload.
A standard 20ft container gives you 160 square feet of floor space. That is fine for a tool crib, a site office for two engineers, or a small archive, but a 20ft box delivers about 14.4 m² of net floor, and a class will not fit. If you are weighing footprints before you call, our breakdown of how container length translates to real usable room walks through why classroom programs jump straight to the 40-footer.
The 40ft High Cube is a different conversation. Strip out the wall depth taken by spray-foam and interior cladding (about 100 mm per side, plus 75 mm each end) and the net usable floor is roughly 27 m² to 27.5 m². That comfortably seats 14 to 18 students at single desks with a teacher zone, or 22 to 28 students in a paired-desk layout, depending on whether you treat the unit as a primary classroom or a specialty room (resource, music, library).
The High Cube’s 2.90 m external height matters as much as the length. Once you furr the ceiling for ducting and recessed lighting, you keep about 2.55 m of finished interior ceiling. That is a real classroom ceiling, not a crouched-tunnel feeling. Standard 8’6″ boxes finish around 2.20 m, which feels institutional in the wrong way. We lay out the full case for the extra foot of headroom you gain by going high cube if you want the side-by-side numbers.
| Shell choice | Net usable floor | Finished ceiling | Classroom verdict |
|---|---|---|---|
| 20ft standard dry | ~14.4 m² | ~2.20 m | Too small for a class; tool crib or two-person office |
| 40ft standard dry | ~26 m² | ~2.20 m | Floor works, ceiling feels low once ducting is furred down |
| 40ft High Cube | ~27 m² | ~2.55 m | The classroom shell: real floor and real ceiling height |
For Van Blanc this is the shell we put in front of every school-board enquiry. Christian LeBlanc, who runs the yard with his father Paul, puts it plainly: “A board’s facilities planner has usually already decided they want a room, not a closet. The 40ft High Cube is the only single box that gives a teacher and twenty-some kids a ceiling they do not duck under. We start there every time.” Two or three units can be joined side-by-side later if a board wants a two-room arrangement with a shared mechanical bay, but the single 40ft High Cube is where we start. The same trade-offs Ontario boards weigh are covered in our guide to what school boards weigh before adding a portable room. One-trip shells are quieter to insulate, easier to certify, and they hold their resale value if the board sells the unit five years later when permanent construction catches up.
How do you prep a cargo box for kid-grade duty?
Prepping a container classroom shell means turning an ocean-grade cargo box into a room safe for children, and it starts before any insulation goes in. A new one-trip 40ft HC arrives with the original marine plywood floor coated in pesticide treatment for ocean transit. That floor cannot stay in a room full of children. We start with a fresh one-trip shell that has crossed the ocean exactly once, then run every classroom conversion through the same sequence:
The eight prep steps before insulation goes in
- Floor extraction: Lift and discard the original 28 mm plywood, including the pesticide-treated layer. The cross-members underneath are inspected and any flagging surface rust is treated.
- Subfloor rebuild: New 19 mm tongue-and-groove plywood goes down on a vapour barrier, sealed at every seam.
- Door blocking: The cargo doors at the end stay if you want a wide service opening for moving furniture in, or get welded shut and clad over if you prefer a sealed back wall.
- Window and door cut-outs: Cuts are framed with welded 50 mm box steel to restore wall strength.
- Roof inspection: Every seam, gasket, and corner casting checked for water-tight integrity before insulation traps anything.
- Corten paint: Original ocean-grade exterior paint left intact, just cleaned and touched up where cuts disturbed it.
- Penetration plan: All future plumbing, electrical, and HVAC pass-throughs mapped before any closed-cell foam goes in.
- Identification plate review: CSC plate stays visible if the unit will ever ship again, otherwise it is recorded in the build file and may be removed during fit-out.
Most national franchises hand this stage off to a sub-trade in another province. We keep it in our Brantford yard so the same hands prepping the shell are the ones who hand it over on delivery day. That is the difference between a classroom that arrives with cold spots six months later and one that holds its envelope for fifteen winters.
How do you insulate a container classroom for a Brantford winter?
Insulating a container classroom for an Ontario winter means breaking the steel’s thermal bridge with closed-cell spray foam and then closing the weak points at the floor and corner castings. Steel boxes are thermal bridges by default. Without an interrupted insulation layer the inside surface of the wall drops to the dew point fast and condensation forms in the cavity. For a classroom that runs at 21 to 23 degrees Celsius with twenty-plus humans exhaling moisture every minute, condensation is not optional to control. It is the design problem.
Closed-cell spray polyurethane foam is the standard answer. We apply 50 mm to 75 mm on walls and 75 mm to 100 mm on the ceiling. The foam bonds directly to the corrugated steel, eliminates the air gap, and gives an effective R-value around R-6 per inch. That puts a typical classroom wall at R-12 to R-18 and a ceiling at R-18 to R-24. Code minimums for occupied space in Climate Zone 5 (which covers most of southern Ontario, including Brantford and Hamilton-Niagara) sit around R-20 walls and R-31 ceilings under the National Energy Code of Canada for Buildings 2020, so we either match those numbers or document why a strapping-and-batt build-up over the foam is being added to close the gap.
Where most container classrooms fail thermally
Not in the walls. In the floor and the corner castings. The steel base rails and the four corner castings conduct heat straight to the ground. A classroom build that skips floor insulation under the new plywood and skips spray foam at the corner castings will feel cold in February no matter how thick the wall insulation is. Specify a minimum 50 mm rigid foam under the new subfloor and a foam-flood at every corner casting.
After spray foam comes interior cladding. Most boards prefer 13 mm fire-rated drywall on metal strapping, taped, primed, and painted in a clean neutral. Some specify FRP (fibre-reinforced plastic panel) on the lower 1.2 m of wall for spill-and-scuff resistance, especially in a primary classroom. We have done both; the FRP wainscot adds to a build and saves repaint cycles for years.
How much electrical service does a 28-student classroom need?
A container classroom needs a 125-amp to 200-amp single-phase service, certified by the Electrical Safety Authority of Ontario, well above what an office box runs on. An office container can survive on a 60-amp single-phase service. A classroom cannot. Once you account for ducted heating, ducted cooling, full lighting, two or three smartboard or projector zones, charging carts for student devices, and a small kitchenette for the teacher’s coffee maker, the calculated load lands between 100 and 200 amps.
Our standard classroom electrical spec runs as follows:
| Service | Specification | Purpose |
|---|---|---|
| Main panel | 125A or 200A single-phase, 120/240V | Future-proofed for expansion |
| Lighting | LED 2×4 troffers, 5000K, dimmable, 6 to 8 fixtures | ~50 foot-candles at desk height |
| Receptacles | 15A duplex every 1.8m perimeter, GFCI in wet zones | OBC code-compliant spacing |
| Smartboard zone | Dedicated 20A circuit, RJ45 + HDMI conduit | Teacher technology wall |
| HVAC circuit | 30A or 40A double-pole | Heat pump or electric furnace |
| Emergency lighting | Battery-backup combo units | OBC 3.2.7 requirement |
| Exit signage | LED self-illuminated | OBC 3.4.5 |
Every panel and every receptacle gets inspected and certified by the Electrical Safety Authority of Ontario. We work with ESA-licensed contractors who file a 2150 wiring notification before any wire is pulled. The school board gets a green sticker and an ESA certificate of acceptance in the build file. Without those documents the board cannot legally occupy the building. We have seen units land on school sites with the wiring done by a friend-of-the-yard and no ESA paperwork. Those units sit unused while the board untangles the certification mess for months. It is the most expensive shortcut a supplier can take.
How do you size HVAC and ventilation to ASHRAE 62.1?
Sizing HVAC for a container classroom means pairing a cold-climate heat pump with a heat-recovery ventilator so the room meets the ASHRAE 62.1 fresh-air benchmark of roughly 7.5 litres per second per person. This is the section where most container conversions fall short. Heating is straightforward: a ducted electric furnace or a cold-climate air-source heat pump rated for 24,000 to 36,000 BTU/h handles a fully insulated 40ft HC down to about minus 25 Celsius. The harder problem is fresh air.
ASHRAE Standard 62.1 sets the ventilation benchmark for classrooms at roughly 7.5 litres per second per person, plus 0.6 L/s per square metre of floor area. For 25 students plus a teacher in a 27 m² room, that lands at approximately 215 L/s of outdoor air, which translates to around 460 cubic feet per minute. Most cargo-container conversions installed in a hurry will run a basic mini-split with no outside-air loop and call it done. The unit will heat and cool fine and the air will stale out in forty minutes. Headaches, drowsy students, falling test performance.
The Ontario reality on outside air
Ontario boards have been pulled into the indoor-air-quality conversation since 2020. Many have written outside-air targets, sometimes higher than ASHRAE 62.1, into their portable-classroom specifications. A correctly built mobile classroom in Ontario today usually includes a heat-recovery ventilator (HRV) rated for 200 L/s at low and 300 L/s at high, ducted through the ceiling cavity so the HRV exhausts stale air while pre-warming the incoming outside air using the exhaust stream. That single piece of equipment is the difference between a classroom that meets current school-board IAQ specs and one that fails the first walkthrough.
We size the HVAC for the unit’s worst-case occupancy plus a comfort margin. A typical mobile classroom container portable school Ontario build leaves us with: one 3-tonne ducted heat pump for primary heating and cooling, one backup electric strip heater, one HRV with intake and exhaust hoods routed through opposite end walls, and ceiling-mounted supply registers spaced for even air distribution. We test temperature variance corner-to-corner during commissioning. Two degrees is acceptable. More than that and we re-balance before the unit ships. That HVAC envelope is non-negotiable for any Ontario school-board occupancy.
What windows and doors does a container classroom need?
A container classroom needs at least three operable double-pane windows along the long wall, a sidelight beside the entry, and an insulated 36-inch commercial entry door, so the room gets daylight, cross-ventilation, and a code-compliant exit. Daylight matters for student attention spans more than most school-board procurement specs acknowledge. Research from the Heschong Mahone Group on California school districts (later replicated in Canadian climates) showed measurable test-score gains in classrooms with adequate daylight versus those without. We build to that finding by specifying at least three operable windows along the long wall plus one window beside the entry door.
The window package on a Van Blanc classroom build:
- Operable casement windows: three units along the south or east-facing wall, 600 mm by 900 mm each, double-pane low-E argon-filled with thermally broken aluminum frames.
- Entry sidelight: a narrow vertical window beside the main door so a teacher can see who is approaching without opening the door, a quiet security feature.
- Window grilles or screens: optional but most boards specify them for safety glazing and to keep operable sashes from becoming exit points.
- Interior shading: top-down/bottom-up cellular shades for daylight control without losing the view.
The main entry door is a 36-inch insulated steel commercial slab with closer, lockset, and panic bar where the occupant load requires one. We confirm exit-count requirements with the board’s plans examiner before fabrication.
How do you make a container classroom accessible?
Making a container classroom accessible means a 1:12 ramp to the raised floor, a 920 mm clear entry with lever hardware, and a 1.5 m turning circle inside, so a mobility device can reach and move through the room. A portable classroom on an Ontario school site has to land at floor heights between 1.0 m and 1.4 m above grade once it is sitting on concrete pads or piers. At a 1.2 m unit floor height that is a 14.4 m ramp run, often folded into a switchback to fit the site.
The accessibility specs we build to
- Ramp run: a 1:12 maximum slope, so a 1.2 m floor height needs roughly a 14.4 m run, usually folded into a switchback to fit the site.
- Ramp width: minimum 900 mm clear; we usually build 1.2 m wide to allow a mobility device and a walking companion side-by-side.
- Landing pads: 1.5 m by 1.5 m at top and bottom and at every switchback.
- Handrails: both sides, 865 mm and 920 mm heights, continuous, 38 mm grippable diameter.
- Surface: non-slip aluminum tread or galvanized expanded metal with a slip-resistant coating.
- Main entry door: 920 mm clear opening, lever hardware (no knobs), threshold under 13 mm, automatic operator optional but specified more often each year.
- Interior turning radius: we leave a 1.5 m diameter turning circle at the door zone and at the teacher’s desk for mobility devices.
The ramp ships as a separate modular component because shipping it attached would exceed legal width on the truck. Our crew assembles and bolts it to the unit on the school site during delivery. Concrete pads under the ramp landings are usually contracted by the school board’s site-services team so the foundation and the unit arrive ready for each other.
What goes into the classroom fit-out?
The classroom fit-out is the finished interior the students and teacher live in for ten months: a front-wall board, a teacher technology zone, back-wall storage, and a small kitchenette. The shell, envelope, electrical, and HVAC are the engineering side. We work from a board-provided room program when possible, but most builds settle around the same anchor elements. All of this fit-out happens at our Brantford yard as part of the conversion work our crew handles in-house before the unit ships.
A 1.2 m by 2.4 m chalkboard or whiteboard goes on the front wall opposite the door. Many boards now specify a sliding-track combo unit: chalkboard on one track, smartboard on the other, with the smartboard pre-wired to the teacher technology wall. The teacher zone gets a 1.5 m by 0.75 m desk with two drawers, a chair, a wall-mounted document camera arm, and a locked cabinet for testing materials.
Student seating uses board-supplied desks rather than fixed installations, because most Ontario boards rotate desk inventory across schools. We leave the floor plan open. Storage cabinets line the back wall: lower cabinets for student backpacks and outerwear (cubby-style for primary classrooms), upper cabinets for craft supplies, science kits, and reference materials. A small kitchenette zone, usually 600 mm of counter with a sink and a small bar fridge, sits near the entry for the teacher’s daily use. Plumbing routes through the same chase as the HVAC condensate line to keep penetrations to a minimum.
How is a container classroom sited and delivered?
A container classroom is sited on screw piles or concrete pads with steel piers, then delivered by tilt-deck truck from our Brantford yard and levelled, bolted, and commissioned on site in a single day for most locations. Most Ontario school sites place portable classrooms on screw-pile foundations or on cast-in-place concrete pads with adjustable steel piers between the pad and the container’s base rails. Screw piles are the faster option (one-day install, no concrete cure) and lift the unit clear of frost heave by anchoring below the local frost depth, which runs 1.2 m in the Brantford area and deeper in Northern Ontario.
Delivery day from our Brantford yard runs in this sequence: tilt-deck truck arrives between 7:00 and 9:00 a.m., positions over the prepared foundation, slides the container off onto the piers, our crew levels and shims, then bolts the unit to the pier brackets. Ramp assembly happens next, followed by HVAC service line connections (electrical conduit from the school’s nearest panel, optional water-supply line from the nearest exterior bib). A board-side electrician makes the final panel connection and the ESA inspector signs off. We aim for keys-in-hand the same day for most sites within 200 km of Brantford. Sites further out (Eastern Ontario, Northern Ontario, far northwest) shift to a two-day delivery with overnight crew accommodation.
This delivery sequence assumes the board has the foundation poured or piles installed before our crew leaves Brantford. We arrive ready to set, level, and commission. We do not arrive ready to wait three days for foundation work. The same tilt-deck setup carries over to our standalone container-versus-trailer rundown for site offices if the board also needs an admin or staff unit.
What do schools actually budget, and how long does it take?
A turnkey single-room mobile classroom container spans a wide budget depending on the package, and a stock-spec build ships in 6 to 10 weeks while a custom board-specified build runs 12 to 16 weeks. What schools budget tracks the package they choose. The entry package gets you a one-trip 40ft HC shell, spray-foam insulation, basic ESA-certified electrical, a single-zone ducted heat pump without HRV, three operable windows, a steel entry door, an accessibility ramp, and a basic FRP/drywall interior. The top package adds the HRV, premium HVAC, FRP wainscot, smartboard pre-wire, double-exit configuration, automatic door operator, and exterior cladding to match adjacent school architecture.
| Package level | What drives the budget at this level | Typical school use |
|---|---|---|
| Basic single-room | One-trip 40ft HC shell, spray-foam, basic ESA electrical, single-zone heat pump (no HRV), drywall interior | Resource room, music, library overflow |
| Standard classroom | Adds full HRV, balanced ventilation, FRP wainscot, upgraded lighting and receptacle count | Primary classroom (K-3), full HRV |
| Premium classroom | Adds premium HVAC, smartboard pre-wire, double-exit layout, automatic door operator, architectural cladding | Specialty room, smart-tech equipped |
| Twin-unit shared mech bay | Two joined shells, shared mechanical/electrical bay, expanded panel, second egress and ramp | Two rooms with shared HVAC/electrical |
Lead times depend on how much custom fit-out the board specifies. A stock-spec build from our yard ships in 6 to 10 weeks from purchase order. A board-specified custom build with their architect’s millwork detail runs 12 to 16 weeks. Compare that to a permanent-construction modular classroom from a national franchise, which often quotes 9 to 14 months from PO to keys, and the container path looks like the bridge solution most boards are actually budgeting for.
Christian LeBlanc, second-generation operator: “School board buyers come to the yard with a printout from their facilities planner and a problem: enrolment outran the building by a hundred kids, the permanent addition is three years out, and the kids need a room in September. The conversation that works is the honest one. We walk the shell, I tell them where the spray foam goes, where the HRV ducts run, where the ESA inspector signs off. They leave with a real lead time and a real number. Two weeks later they have a purchase order from the board and we are building. That is how this is supposed to work.”
Frequently asked questions
How many students fit in a 40ft container classroom?
A 40ft High Cube classroom seats 14 to 18 students at single desks with a teacher zone, or 22 to 28 students in a paired-desk layout. The net usable floor after insulation is roughly 27 m². Whether you treat the unit as a full primary classroom or a smaller specialty room (resource, music, library) sets where you land in that range.
Is a container classroom warm enough for an Ontario winter?
Yes, when it is built correctly. Closed-cell spray foam bonds to the steel and eliminates the thermal bridge, with 50 mm to 75 mm on walls and 75 mm to 100 mm on the ceiling. The weak points are the floor and corner castings, so we add rigid foam under the new subfloor and flood the corner castings with foam. A cold-climate heat pump rated for 24,000 to 36,000 BTU/h holds the room comfortable down to about minus 25 Celsius.
Does the classroom come with ESA-certified electrical?
Yes. Every panel and receptacle is inspected and certified by the Electrical Safety Authority of Ontario. We work with ESA-licensed contractors who file a wiring notification before any wire is pulled, and the board receives a green sticker and an ESA certificate of acceptance in the build file. Without those documents a board cannot legally occupy the building, so we never skip them.
How long does a mobile classroom container take to build and deliver?
A stock-spec build from our Brantford yard ships in 6 to 10 weeks from purchase order. A board-specified custom build with an architect’s millwork detail runs 12 to 16 weeks. Delivery itself is a 1-3 day window to most Ontario regions from our four Brantford yards, and we level, bolt, and commission most units in a single day on site. Every quote comes with a real lead time, not a hopeful one.
Can two container classrooms be joined into a larger room?
Yes. Two or three 40ft High Cube shells can be joined side-by-side with a shared mechanical and electrical bay, an expanded panel, and a second egress and ramp. Many boards start with one unit and plan for a twin-unit layout later as enrolment grows. We map the shared-bay penetrations during the first build so the second shell ties in cleanly.
Sources
- Government of Ontario. (2024). Building Code (O. Reg. 332/12), Section 3 (Use and Occupancy). ontario.ca/laws/regulation/120332
- National Research Council Canada. (2020). National Energy Code of Canada for Buildings 2020, Climate Zone 5 envelope requirements. nrc.canada.ca
- ASHRAE. (2022). Standard 62.1 – Ventilation for Acceptable Indoor Air Quality, classroom rate procedure. ashrae.org
- Ontario Educational Collaborative Marketplace (OECM). (2025). Modular Buildings and Portable Classrooms supply and installation agreement. oecm.ca
- International Organization for Standardization. (2022). ISO 6346:2022 – Freight containers, coding, identification, marking. iso.org/standard/82754.html
Placement requirements vary by municipality. A quick call to your local planning office before delivery is the easiest way to confirm what works for your property.
Reach Van Blanc in Brantford
We have been supplying shipping containers across Ontario since 1995. Our warehouse is at 90 Morton Avenue E in Brantford, and we deliver right across the province on a cash-on-delivery basis. No surprise fees, no chase-the-paperwork.
Van Blanc Ent. Inc. – 90 Morton Ave E Unit 1B, Brantford, ON N3R 7J7 – +1 888-509-6658
If your school board is sizing a mobile classroom container portable school Ontario build for September enrolment, call Christian at our Brantford yard. We will walk a 40ft High Cube shell with you, talk through the spray-foam and HRV specification, and quote a real lead time tailored to your site.
Ready to price your container?
Tell us the size and your postal code and we’ll send back an honest, all-in number, container, delivery, and placement, usually within 1-3 days. No pressure, no mystery fees.
Family-run in Brantford since 1995 · 200+ containers in stock · 4.9★ across 124+ Google reviews · every box graded by a person, walk it before it lands.