Concept · for discussion

Spine-and-Pillar Panel House

A single-storey house where the only structural steel is a ridge beam (the spine) on pillars every 6 m. The walls are 100 mm IBR / EPS cold-room panels standing in folded U-tracks, and the roof panels span from the walls up to the spine. Two versions: A with the door in the long wall, B with a glass slider in the gable end and a covered verandah.

Artist's impressions of version B: panel and plastered finishes and three colour palettes — Artist's impressions of version B. Option 1 is the base panel finish; plastered and colour options are upgrades. More in the Gallery tab.

How it goes up

Footing: a slab or strip footing under all the walls, with a pad under each pillar. The base U-track is bolted down round the edge.
Steel: the pillars stand on their base plates and the 200 × 100 ridge beam sits on their cap plates. In version B the Gable A pillar stands on a welded door frame instead, and the spine runs on over the verandah to an open steel A-truss.
Walls: the 1.2 m wall panels stand in the base track and a top U-track caps them. The panels carry the roof edge and hold the house square, so keep enough solid panel in every wall.
Roof: the roof panels span 3.46 m from the wall track up to the spine, screwed at both ends, with a 300 mm eave overhang.
Windows, door or glass slider into the panel openings; ridge capping, barges and trims.

Gallery · artist's impressions

What it could look like

AI-generated impressions made from the 3D model. They show the mood and the finish options, not a built house: details such as gutters, lights, joinery and landscaping are illustrative.

Artist's impression of the open-plan living, dining and kitchen, with a vaulted ceiling, central pillar and glass sliding doors to the verandah — Version B interior, looking to the glass slider and verandah. In the design the spine and pillar are steel; the timber look shown here would be a timber cladding finish on the steel, at extra cost.

Walkthrough, version B

26-second walk from the verandah, through the glass slider and living area, into the bedroom. Simple block model: proportions are right, finishes are not shown. Needs a connection to play.

3D model views

3D model view of the version B living area looking to the glass slider — Version B living area, looking to the glass slider. This is the view the interior impression above was made from.

3D model view of the version B bedroom from the doorway — Version B bedroom from the doorway.

3D model view of the version A bedroom from the doorway — Version A bedroom from the doorway.

Exterior finishes

Five exterior impressions: panel look, plastered look, and three colour palettes — Version B exterior finish options. Option 1 is the base panel finish; option 2 (plastered) and the colour palettes are upgrades to price separately.

Earlier artist's impression of the house in a dry garden — Earlier impression of version A with a plastered finish.

How it works

Spine, pillars and panel walls

The ridge beam is held up by pillars, so the roof does not push the walls outwards and there are no rafters, ties or purlins. The walls are load-bearing panels held top and bottom by light folded U-tracks, as in a cold room. Structural steel for version A is about 0.33 t.

Cutaway, version A

1 ridge beam · 2 gable pillar · 3 middle pillar · 4 base U-track · 5 top U-track · 6 roof panel · 7 wall panel · 8 footing. Front 7.2 m drawn without panels to show the structure.

End section through a pillar

Version A vs version B

	A · LONG-WALL DOOR	B · GLASS GABLE + VERANDAH
Entrance	900 × 2100 door in the front wall	3.6 × 2.1 m glass slider in Gable A
Outdoor space	None	6 × 2.4 m covered verandah, 14.4 m²
Structural steel	≈ 0.33 t	≈ 0.65 t
Steel pieces	Spine 2 × 6 m, 3 pillars	Spine 2 × 6 m + 2.4 m, 2 pillars, door frame (2 legs + head), short pillar on the head, A-truss (2 rafters + tie), 2 verandah posts, 2 eave beams
Roof panel	91 m²	109 m²
Wall panel	97 m²	89 m²
Glazing	11 windows	7 windows + 7.6 m² slider
Gable A bracing	5 solid panels	2 solid panels; the welded door frame must brace the rest
Footings	Strip or slab + 3 pillar pads	+ 4 pads (door legs, verandah posts) + deck
Layout	Bedroom and bath at Gable A	Living opens onto the verandah at Gable A; bedroom and bath move to Gable B
Biggest extra cost	—	Slider unit, then the welded frame and deck

Will the door frame flex?

Downwards, not much. The short pillar brings about 6 kN (≈ 600 kg) from the spine onto the middle of the 3.6 m head. A slider jams if the head sags more than about 1/500 of the span, roughly 7 mm. A 200 × 100 × 4 head, the same section as the spine, should sag about 2 mm.

Sideways is the real problem. The glass removes 3 of the 5 panels that hold the house square at that end. The door frame has to take over: welded or haunched corners, and each leg bolted to its own pad with four bolts so it cannot rock.

Wind on the glass. 7.6 m² of glass catches a lot of wind. The slider needs a wind rating, and the verandah roof shelters it.

First estimates for the engineer to check, not a design.

Open questions

Panel figures from the factory: load a 2.4 m wall panel can carry, roof panel span (3.46 m here), and racking strength of a gable wall.
Engineer: spine size (200 × 100 × 4 RHS assumed), pillar size, cap and base plates, roof tie-down for wind uplift.
Version B: welded door frame design (corners and leg bases) and the verandah A-truss.
Gable panel layout: start each gable with a half panel so a joint lands on the centre pillar.
Price and availability of folded U-track and of 50 mm panel for internal partitions.

Layout planner

Doors and windows

This is version A. Every wall is a row of 1.2 m panels. Tap a panel to make it a window, tap again for a door, again for solid. Your layout is saved on this phone and used by the 3D view and the costing.

Plan · back wall at top, entrance front at bottom

Front elevation

Solid panel, 1.2 m

Window 1000 × 1200, sill 900

Door 900 × 2100

Pillar under the spine, every 6 m

Bracing check

Rule of thumb for panels acting as bracing, to be confirmed by the engineer.

3D view

Walk round the house

Drag the picture to turn it. Switch between version A and B, use the build steps to see it go up layer by layer, or lift the roof off with Floor plan. Version A uses your layout from the Layout tab.

Version

Show

Build it step by step

Cladding

Rotate

Tilt

Costing

Cutting list, prices and quotes

Quantities follow the package, the version and your window layout. Type each supplier's unit price (US$) to compare; the cheapest per line turns green. Prices, names and numbers are saved on this phone.

Price comparison

Request quotes on WhatsApp

Message preview

With no number entered, WhatsApp opens and lets you choose the contact.

Steel cutting list

Spine pieces are cut to the pillar spacing (6 m, or 4.8 m for the 2-bed). Lengths are approximate until the engineer sizes the steel and the plates are detailed.

Panels pre-filled at $38.40/m² for 100 mm. Screw and track quantities are estimates. Excludes foundation, plumbing, electrical, finishes, transport and labour on site.

About this app

Notes

This app is a concept for discussion, not a construction drawing. All structure needs an engineer's check before fabrication.