Building systems

What it does

See how structure, enclosure and services occupy the same building.

Move from the whole house to a component or a junction, keeping its surrounding systems visible.

When it fits

Learning where an assembly belongs and which other systems meet it.

The trade-offs

This is one wood-frame house, not a template for every building type.

Context. An educational model. Geometry, material assumptions and the reference building are described in the illustrated study.

This is the house the rest of the collection keeps coming back to. Each of the other figures takes one part out of a building and tests it on its own: a beam on a bench, a strut in a press, a wall racked by weights. This one puts the parts back together, in one ordinary house, so you can see where each lives and what it touches. A stud here is the same stud as in Platform framing, a truss the same truss as in Trussed rafters. Click any part and it is lit in place, with a link to the figure that draws it on its own; every figure links back here.

One house, drawn whole

It is a plain two-storey house of light wood framing on a full basement, the way a great many North American houses are built. Every member is drawn at its true size and spacing, from the anchor bolts to the shingles.

Plan	36 × 24 ft (11.0 × 7.3 m), two storeys, a basement under all of it
Foundation	8 in (205) concrete walls on 20 × 10 in (510 × 255) footings; a 4 in (100) slab
Floors	2×10 joists at 16 in (405), lapped over a 5⅛ × 12 in (130 × 305) glulam girder on two steel columns
Walls	2×6 studs at 16 in (405), 8 ft 1⅛ in (2467) plate to plate, OSB sheathing
Roof	Fink trusses of 2×4 at 24 in (610), 6 in 12, spanning the full 24 ft (7.3 m)
Storey	107⅛ in (2721) floor to floor: 15 risers of 7⅛ in (181)

The systems

The house brings together three kinds of system: a structure that carries loads to the ground, an enclosure that keeps the weather out, and the services that make the inside habitable. The structure has two halves, the substructure below the first floor and the superstructure above it. The legend under the figure follows the same order, and so does the list below.

Foundation: Footings, basement walls and the drain beside them, the slab, and the columns under the girder. Spread footings, Columns.
Floors: Sill and anchor bolts, the girder, joists and rims, the subfloor: two platforms, each a floor to build on. Platform framing, Beams.
Walls: Studs, plates and headers; sheathing that turns each wall into a shear wall; steel straps that tie storey to storey. Lateral stability, Load path.
Roof frame: Trusses, their bracing and hurricane ties, the roof sheathing, and the porch hung from its ledger. Trusses, Trussed rafters, Truss connections, Roof framing.
Enclosure: Shingles, flashing, house wrap, siding, insulation, windows and the door. Wall assembly.
Interior: The stairs, partitions and gypsum board. Stairs.
Services: A furnace and its ducts, the plumbing stack from the building drain to its vent through the roof.

Where systems meet

A building is mostly joints. Each system is simple enough on its own; the trouble, and most of the craft, is where two of them meet. The ringed dots on the house mark seven such places. Open one and the house falls away, the camera closes in, and the joint is rebuilt piece by piece in the order a crew would put it together, nails and bolts at their real size, each layer stepped back from the cut so it can be read. At every joint the same three questions answer it: what bears on what, what is fastened to what, and what laps over what so that water runs off.

Foundation meets floor. The sill is bolted to the concrete, the floor bears on the sill, and the sheathing and siding are run down past it so water drips clear of the joint.
Floor meets wall. The second floor bears on the walls below and the next walls stand on it; a strap and the sheathing stitch the two storeys together, and a flashing over the band board is lapped by the wrap above.
Wall meets roof. The truss heel sits on the top plate, held down by a hurricane tie; the air path runs from the soffit, past a baffle, to the ridge; the drip edge, underlayment and shingles each lap the one below into the gutter.
Window meets wall. The header carries the wall over the opening; a sill pan, jamb tapes, head tape and the wrap’s flap are laid in shingle order, so any water that gets past the trim is led back out.
Stair meets floors. The stairwell is framed with doubled headers and trimmers on hangers; the stringers stand on the floor below and hang from the header above.
Services through the structure. The vent stack runs in a wet wall, through bored plates protected by steel, beside a truss rather than through it, and out of the roof in a boot lapped into the shingles.
Porch meets house. A ledger is bolted to the rim, never to the siding, and flashed so the water from the wall above passes outside it.

Reading the drawing

Show: Hide whole systems: take off the enclosure to see the frame, the ground to see the basement.
Level: Cut the house down a floor at a time, 4 ft (1220) above each floor, which is where a plan is drawn: the walls are cut through the windows, and what is below shows in place.
Apart: Lift the house apart in the order it was built: foundation, floor, walls, floor, walls, trusses, roof.
A part: Click a part, or its name below, and the house clears what stands in front of it and turns to show it. The arrow beside each name opens the figure that draws it on its own.
A joint: Open a junction and step through it with N and B, or let it build itself.

The address keeps up with you: ?part= for the part in view, ?hide= for the systems taken away, ?junction= for an open joint. Any view can be copied and shared, and the other figures use the same addresses to point back here.