This is an evolving web site

Update 22-02-22: The project is almost complete. Major lesson learned was not to deliver the units with the columns and beams “bolt in”. Not safe to lift and install without a hiab, and all it saves is one tow. Instead we will design each unit at full height – welding the columns and beams in place and towing each half separately.

This also means adding columns about 600 mm from the corners. Without this support, the four corner posts may shear during towing. 

Since October, price of steel has increased $1,000 and more increasing coming.

Bloke Built Box is a 30 m² galvanised steel framework that comes (optionally) as two trailers then bolted together. Tow it home or opt out of the trailer part – save about $700 and have a hiab collect and deliver.

Set up on site and begin the process of infill – walls, floor, roof, joinery, cladding, insulation, lining. If you don’t want to engage with the council read the rules and know the law (don’t rely on council advice).

To be clear, we sell the structural steel frame on wheels – the hard part. You then buy and install the infill and finish it.

Target market: Blokes – people handy with tools, common sense, with more time than money. DIY

The product is the metal framework, optionally on a trailer axle for towing. It uses heavy steel that allows wide openings in the walls – giving considerable flexibility in regard to layout.

See the jpg link for progress photos of the first job


Galvanised Steel Framework


This is what is offered for sale: A steel frame optionally with axles, springs, wheels and tow bar.


This is the prototype after our blokes dressed it. The sliding door cost $1 on TradeMe (no one else bid but we had to remove it from the seller’s house). The cladding looks amazing but was another deal – surplus stock the vendor needed to get rid of – cost less than Shadowclad. The tiles are glued onto timber strips that are top/bottom bolted to the walls. When the trailers are moved, the vertical panels are unbolted and transported separately. Preparing for transport should take less than a day. The rest? We made the windows ourselves using H3.2 timber and acrylic frosted panels. All the decks and steps are stand-alone… not attached to the trailers. Inside, because it is a studio the walls and floor are plywood. Inside the walls are Expol rigid insulation panels to NZBC.


On legs or On wheels – your choice (image below is one half of the unit – both units are ready to bolt on axles, but easiest is to buy one to tow, other on top).


The B-Cube is made up of two halves. Both have trailer wheel axle and draw bar mounts. If you tow it home, the bottom trailer has the wheels. If you want both to have wheels, it’s an option. We order the axles, cut and weld the second set to fit the second trailer. The second trailer already has the draw bar sleeve and the axle mounts, both for customers who plan to move the unit later and for customers where the council insists the units must be on wheels to be excluded from the Building Act. In regard to the latter, we believe this is a misinterpretation of Section 8 of the Building Act that defines what a building is, but ensuring both halves can be towed tends to shut down the issue.

Photo before the columns, gable trusses and roof beams were packed on the trailer.


B³: The Bloke Built Box – tow it home, set it up, fit it out – instant bach, barn or shop

The Bloke Built Box (B³ or B-Cube)

The double-wide kitset

Think of them as building blocks. You get two platforms, one on wheels the other on top, to tow home. Loaded, the total height is about 1.25m, with a gross weight of about 1,100 KG. If you want to collect infill materials like a packet of H3.2 plywood from a cheaper supplier in Auckland, you have 900 KG to play with. That’s just about the weight of a packet of CD plywood (12mm = 45 sheets = 855 kg).

Each unit has half a gable roof, and they join flush together forming a 5.0 x 6.1m footprint with a cathedral ceiling.

The floor area (GFA) is 28.8M² if the two halves are butted together. If you add one 50mm wide H4 RS timber on each of the two units (and there are some good reasons to do this) the floor area expands to exactly 30 m².

You tow it home, set it up and fill it in with easy-to-work timber and finishing materials. Or if you prefer to have the units delivered on a hiab, you can opt out of the axle and trailer wheels and save about $1,000.

The B-Cube can be a basic barn using plywood, or an elegant office or sleepout with architectural-grade cladding of your choice. It can be a permitted building, an exempt building (it’s under 30 m²) or, if it’s not fixed to land,  a chattel shelter excluded from the authority of the Building Act

To learn more about the complexities of NZ law and regulation,  click here. Having been in the mobile home business, we are aware of the complexities, and designed B-Cube to avoid some common traps.

If you can’t find it, build it

We do the hard part

Welding HS (hollow section) steel to form a framework is hard. It takes years to become a master welder.

Infilling a premade steel frame with timber, plywood & ordinary building materials is easy for a bloke handy with tools.

The Bloke Built Box is a galvanised steel, two-part externally framed kitset to make it fast, easy and affordable to finish. You pay us for the hard work, then finish it to whatever standard you desire.

With three of the sides flush, you have flexibility in design. Join two, or end to end.


You do the rest

We make a strong-steel kitset. It’s made in two parts so you can tow it home behind a 2000 kg rated ute (no trailer brakes). Both platforms are designed as trailers but we stack them so it’s one trip home. Total weight of the two units is about 1,100 kg.

Set them side by side, bolt in the columns, attach the roof trusses and connect the ridge and wall beams. Now you have a solid structure ready to infill.

We find the easiest is to glue & screw H4 rough-sawn 50mm timber to 50mm wide RHS to give you a solid timber base to add studs and rafters. The exterior walls are 2.7 high to fit readily available plywood. Everything is designed with NZ-sourced materials in mind.

You can make a modest home, a barn, a sleepout or a workshop. You can fix it to  land , or have it here today, gone tomorrow.

What you get

Two pre-welded B³ platforms, stacked.

  • Optionally its a tow-home trailer
  • Or it’s a ready-for-hiab kitset

Each one of the two packs consist of:

  • 6.1m x 2.5m (20′ x 8′) platform 150x50x3 RHS
  • 4 internal spreaders 150x50x3 RHS @1.2ø
  • 4 bolt-in columns – (2.4 m high) – 50x50x5
  • 4 welded legs at each corner – 156mm AGL
  • Pre-welded end trusses
    • Truss raises cathedral ceiling to 3m
  • 6 m ridge beam 150×50 (bolted to 2nd one)
  • 6m wall beam 150×50 (braced w. studs/ply)
  • All connecting bolts and plates & cleats
  • Useful advice on material sourcing

Trailer Option

Drive to Auckland with your ute/SUV rated for 2000 KG towing. Pick up a rego plate, get a 3-year WOF and stop by lower-cost supply yards for things like a pack of H3.2 plywood.

  • Set up as a 2.5 x 6.1 x 1.25m tall trailer
  • Optional 2000 kg torsion axle (no brake)
  • Optional removable towing bar & hitch
  • Bring your own magnetic towing light bar
  • Ready for Rego and 3-year WOF


The NZ building industry is expensive and time-consuming with far too much money going into consent paper, not floors, walls and roofs. We started by making mobile homes – 3.0 x 8.0 but found for many they are too narrow, and management of a factory to get each finishing detail right adds factory-floor complexity that blokes can handle on their own.

So we stepped back and looked at what is hard versus what a handy bloke can do.

  • Use GHS steel; bloke finishes with timber
  • Make the room wider (≤5m)
  • Keep the floor area ≤ 30 m²
  • Keep the floor-ceiling height ≤ 3.5 m
  • Keep it LTSA permitted height (≤4.25m)
  • Keep it LTSA permitted width (≤2.55m)
  • Keep it easy to tow (6.1m plus draw bar)
  • Keep it light to tow (≤ 2000 kg)
  • Make it easy to pack with extra plywood
  • Make the overhead bits easy to set up
  • Make it easy to finish, with a strong frame
  • Make it durable & sized for NZ products
  • Make it easy to fit surplus joinery
  • Make it affordable. Control cost & time
  • Make it flexible. Connect units together


What we recommend

  • We like 75×50 & 100×100 R/S H4 timber
  • Roughen the GRHS, glue & screw timber to it
  • This gives a timber frame inside the steel
  • Add 75×50 studs @ 40 or 60 cm centres
  • Attach 2.7×1.2 H2.3 plywood to exterior
  • This covers the exterior wall height
  • Then decide how to clad
    • building wrap and cavity wall
    • reconstituted limestone bonded to XPS
    • real stone veneer over XPS
    • for barn, battens over plywood joints
  • Roof rafters: we like 100×100 RS exposed H4
    • Inlay R3.3 XPS insulation 100mm thick
    • Cover all with H3.2 plywood
  • We like EPDM (rubber) geomembranes
    • Buy 6.3 x 5.5 and drape over both units
    • This waterproofs everything
    • But it can be easily removed for transport
    • Then cover with a protective roof material
  • Insert 2 150×50 timber beams in between and widen up to 30 m² floor area.

Avoid Avoid Avoid

It’s a bureaucratic nightmare out there and many of the B-Cube details are work-arounds. Read the section on NZ Law and Regulations.