Sun — which opening, not how much
Every opening is sampled on a 3 × 3 grid across its pane, at the ten Dec 21 and Jun 21 suns (8 am – 4 pm), with a ray against the massing and the landform. The panel: Winter sun kept, Summer sun cut, the pane that earns the most winter sun and the one that takes the most summer sun, and a table per opening — winter and summer gain (square metres of glass squarely facing the sun) and summer ÷ winter. A dash means no sun of that season reaches the pane at all: an orientation fact, not a shading one. The sheet draws each opening's winter and summer bars (outline = available, fill = collected) and, after Sweep it — winter kept vs summer cut, the overhang study curve. Nothing after 4 pm is sampled, so a west window's evening problem is understated.
Air — the mechanism, not the total
Each opening is named windward or leeward (for the wind) and inlet or outlet (for the stack, by height; roof openings are always outlets). The two flows are reported separately and combined in quadrature (BS 5925). Every area here is the part of the opening that opens, set by opens as. Effective open area is the most useful row: the openings work in series, so the smaller side governs — doubling the bigger one buys almost nothing. Also: To purge by the wind alone / by the stack alone (the area the smaller opening needs to reach 4 air changes an hour), One-sided rate (a room with all its windows on one wall), Plan depth against reach, and with a weather file Night-flush hours, Works across the year (the share of the year's hours the wind comes from a useful direction) and the ventilation year — every hour of the file run through an EnergyPlus-style network: the share of the mild hours (68–79 °F outside) the openings purge, the hours nothing moves, whether wind or stack leads, and the median rate. The sheet adds a plan of the openings, the two circuits with the governing side marked, and a rose of the cross-flow at all 16 wind directions.
How far each kind of sash opens — the share every air number multiplies an opening's area by (typical figures, not a measured window):
How far each kind of opening opens| Opens as | Share that opens | Why |
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| Whole opening | 100 % | a door, a folding or sliding-away wall, an unglazed hole, or any sash that clears its whole frame — what every air number assumed before this control existed |
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| Casement, side-hung | 90 % | a side-hung sash swung to 90° clears nearly its whole frame; the frame and stop take the rest |
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| Louvres / jalousie | 80 % | blades fully open: their edges and the frame take about a fifth |
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| Sliding / double-hung | 50 % | one sash slides over the other, so at most half the glass is ever uncovered |
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| Awning / hopper, top- or bottom-hung | 40 % | a top- or bottom-hung sash held at about 30°: the gap along the free edge and the two side wedges — the effective-area rule of thumb for top-hung lights (CIBSE AM10 §4, BRE Digest 399) |
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| Tilt-only / trickle | 15 % | a tilt-and-turn on its tilt, or a night-vent stop: the wedge at the head and two narrow side gaps |
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| Fixed | 0 % | a fixed light: daylight and a view, no air at all |
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View layers → Air (in Viewport display) draws the air in the model — round the building and through the room — and adds a readout: the air through the room, each opening in or out, the neutral plane in a calm (openings below it breathe in, above it out), the breeze across the floor and at the focus, What that breeze is worth (ASHRAE 55: about 2 °F cooler at 1.3 mph, 4 °F at 2.7 mph), and where each opening's air goes. It is potential flow — read the path, not the evenness. Run CFD runs a real CFD simulation in your browser (15 seconds to three minutes) and adds The room's air: air-change time, the age of the room's air, and air-exchange efficiency (100 % piston flow, 50 % evenly stirred, under 50 % short-circuiting). The flow totals are the Air sheet's, not the drawing's.
The wind outside is drawn as three families of line, each its own box under The lines. Street: lines started on a curtain upwind that spans the building from just above the ground to a little over the roof, each drawn from one building height upwind of it to two and a half downwind — the wind parting round it and over it. Along walls: 32 lines started just off the building’s solid faces, windows or none — the wind stopping against a blank wall, running along it and round the corners (after a CFD run on every face; in potential flow on the windward faces only, because behind the building potential flow draws a mirror of the front, which real wind never does). Eddy, after a CFD run only: 24 heavier lines on a pale casing, started where the air behind the building runs back toward it, against the wind, and followed round for 3 turns. It is the average over the run: at any moment gusts cross it and it sheds and re-forms. Potential flow has no eddy, so it draws none. The lines through the room are drawn outside only for a building height and a half of travel before the inlet and after the outlet.
That readout opens with Read the drawing: one row per mark in the picture — the dashes, their colour, the rings on the openings, the wind arrow, the places no dash goes — each saying what it measures (the same figure the stats under it print), what it means for a person in the room at this place and date (a draught or a cooling credit, heat carried out of a heated room or brought in on a hot afternoon, a placeholder wind or the sector the year really blows from), and the move. Hover a row and the model lights its mark; the colour row draws the standing points the breeze is read at. With the drawn air on the date, the two buttons under the rows take the Date + time bar to a January morning and a July afternoon — read both before you decide an opening is right.
Mass — how much of it is working
Only the first few inches of a slab take part in a daily cycle — the penetration depth. The panel: Mass actually working (ft³), Inert on a daily cycle (%), Time constant, Decrement factor (the share of the outdoor swing that gets inside — heavy 0.2–0.4, light 0.7–1.0), Time lag (hours the indoor peak trails the outdoor), and Indoor swing. The sheet draws the 24-hour swing outside and in, and the slab in section with the working depth marked. Pick the material in the rail:
Mass materials and how deep a daily temperature swing reaches into each| Material | Density | Daily penetration depth | Source |
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| Dense concrete | 144 lb/ft³ (2300 kg/m³) | 5.7 in (0.145 m) | CIBSE Guide A, dense cast concrete |
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| Brickwork | 109 lb/ft³ (1750 kg/m³) | 4.7 in (0.120 m) | CIBSE Guide A, fired clay brick |
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| Limestone | 137 lb/ft³ (2200 kg/m³) | 5.7 in (0.144 m) | CIBSE Guide A, sedimentary stone |
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| Rammed earth | 125 lb/ft³ (2000 kg/m³) | 4.9 in (0.124 m) | Standards Australia HB 195, stabilised rammed earth |
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| Concrete block | 87 lb/ft³ (1400 kg/m³) | 4.6 in (0.117 m) | CIBSE Guide A, medium-density block |
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| Cross-laminated timber | 30 lb/ft³ (480 kg/m³) | 2.7 in (0.068 m) | CIBSE Guide A / EN 16351, softwood CLT |
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| Water (a mass wall) | 62 lb/ft³ (1000 kg/m³) | 2.5 in (0.063 m) | the reference case — the highest volumetric capacity a building can hold |
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View — a direction, and its conflict with the sun
Read from up to 81 standing positions on the floor inside the walls, not one point. A position shares the view when at least 0.1 sr of glass faces the view from it (about a 3 ft × 3 ft window seen squarely from 10 ft). The panel: Floor that shares the view, View quality, best → worst, which way the glass faces, View against sun (the angle between the view target and the winter sun — past 90° every pane has to be argued for twice) and Glass serving both. The sheet is a rose of where the glass looks, with the view and the sun on one dial. (The Readout's view rows use a different eye: one seat at the focus.)
Shadows
Plan shadows of the massing on Dec 21, the equinox and Jun 21 at 8, 10, 12, 2 and 4 o'clock, winter darkest, with how far the winter-noon shadow reaches north. A drawing; it has no verdict card.
Year — the overhang study as a curve (weather file)
Solar energy on the glass month by month, from the weather file's own sky (kWh/m², metric by house rule): outline = the open sky, fill = what your massing lets through, and a strip below of the share it blocks each month. A good overhang blocks most in summer and least in December. Beside it: the eight compass faces of the opaque skin, open against actual. The sun calendar needs no weather file: pick an opening and it draws every day of the year across and every half hour down — night, shaded, or in sun — with sunlit hours a year and the best and worst month. The sun-path dial paints the same opening's shading on the sky dome.
Climate (weather file)
Each month's coldest and hottest hour, and its mean, against the 68–79 °F comfort band; the share of hours the place is cold, comfortable or hot on its own; heating and cooling degree-days counted against the band's edges, not the almanac's 65 °F base (so never put them beside published HDD65 figures); and the strategy mix — what share of the year passive solar, ventilation, mass and evaporative cooling could cover here, against what this design captures.
Earth (landform)
Slope under the footprint and which way the ground faces, relief under the building, the pad cut · fill of a level pad at the plinth's base (with its error bar), net earth in or out, the catchment draining through, channels through the footprint and standing water under it. The sheet is a contour plan with the drainage lines; under it, a site section along the fall line with cut and fill hatched. Seat the landform swings cut against fill. Screening resolution: a landform study, not a grading plan.
Balance
Sun, air, mass and view side by side on four gauges — summer ÷ winter, air changes, share of the swing damped, share of the floor with the view — deliberately not added up. There is no single score, on purpose.