The Body House · the model
The sun on it
Sheet 06, made draggable.
The drawing set built as one solid — 70.62 m² on the ground, 7.28 m to the parapet, from the same 12-point outline and the same levels as the plans. Drag the year underneath it and the shadow of the upper brow comes down the south wall, crosses the head of the glass in the last week of March, and gives the glass back.
The numbers beside it are not a caption. They are the rule printed on Sheet 06 — shadow line = soffit − projection × tan (altitude) — worked out live, in millimetres, for wherever you have put the sun.
The model
The 3D needs JavaScript, WebGL and a connection. The twenty sheets need none of the three, and the arithmetic below is on this page already.
Solar noon at 27.7° N
20 March
Equinox · as published on Sheet 06
| Altitude | 62.3° |
|---|---|
| Soffit | +5.94 |
| Projection | 210 mm |
| Shadow line | +5.540 |
| Head of glass | +5.51 |
| Clearance | clears 30 mm |
Governed by the brow, 8 mm below the drip band's line. In the cold months the band governs instead.
Between the four published dates the sun's height is interpolated through them, not taken from an ephemeris — so the drawing and the page can never print different numbers for the same day.
What you are looking for
Set it to 22 December. The sun is at 38.9° and the governing line is at +5.636 — the drip band, not the brow — clearing the head of the upper glass by 126 mm. Every millimetre of that glass is taking sun on the shortest day of the year, which in a house at 2,300 m heated by one stove is the entire point.
Now drag to 20 March. 62.3°, and the governing line has come down to +5.540, clearing the head by 30 mm — the brow having taken over from the band a few days back, at 61.6°, where their two lines cross. Six days on it reaches the head and starts cutting: 26 March, at 64.2°, which is the date Sheet 12 arrived at separately. That is what the 450 brow was getting wrong: on this date it put its line at 5.083 and cut 427 mm of the glass, a third of it, in the season when heat is still wanted.
Then 21 June. 85.7°, and the line is below the sill entirely. The glass is fully shaded and stays that way through the hot months, off the same 210 mm of slab edge that let the whole of December in.
One rule, both brows, four dates. Projection = drop ÷ tan (90° − latitude), which is 0.525 at 27.7° N — and a shading number without its latitude is meaningless.
A note on this model
It is the drawing set built as one solid, in metres, from house-geometry.js — the same outline, the same eleven levels, the same openings the plans are dimensioned off. It includes the Stage 5 ground: the apron, the seat wall, the cherry, the cut bench, the retaining wall, the wood store and the roof-water run.
It is not a rendering and it is not trying to be. There are no materials beyond four flat colours: lime render, stone, timber, glass. Sheet 11 is the drawing that shows what this house looks like from a position a body can occupy, and it is a drawing rather than a render for the reason set out there.
Download it as OBJ or GLB from the corner of the frame. There is no AR here — that is the village viewer, which is a different tool for a different job.