Learn · Reference · 13 min read · Updated September 2026

Sha, the catalogue of faults

The tradition names its faults. A road at the door, a road that curves away, a corner aimed at a window, the slit between two towers; inside, a door in line with a window, a beam over a bed, a wall’s edge, a stair at the entrance. What the names are, where the word comes from, what they have in common, how far each reaches, what the manuals do about them, and what the research can say at each range.

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Metal

Fig. 01 A diagonal of light across a tiled wall. The tradition’s faults are all lines like this one, aimed at a place where someone rests.

Every practice has a list of what goes wrong, and feng shui’s is unusually well named. The manuals call the faults sha, and give each its own compound: the road-rush, the reverse bow, the pointed corner, the sky-cut, the through-house, the beam over the head, the wall blade. This page draws the catalogue by range, from the pillow to the skyline, says what each name means and where the word came from, and then does what the manuals mostly do not, which is to ask what the eight have in common and which of them anyone has measured.

What the word means

Tradition · Sha, and its arrows

Sha, 煞, is the tradition’s word for qi that harms: cutting, rushing, pressing, piercing. The character is the one for killing with a stroke added, and the older texts use it for the wind that strikes a site from an unsheltered quarter and for the water that runs straight at or straight away from it: the Zangshu’s opening, that qi scatters on the wind and stops at water, is the first sha, and Paton’s translation gives the landform faults that follow from it, the exposed ridge, the straight watercourse, the gap in the flanking hills through which the wind comes. The manuals extend the word to anything with an edge, a line or a gap that points at a place where a body rests or arrives. The popular English for the family is poison arrows, a phrase from the 1980s manuals rather than the texts, and it names the reading exactly: each sha is an arrow, and the question is always what it is aimed at.

The faults, by range

Fig. 01 The faults, by how far they are from the person they are aimed at. At the centre a sleeper; around them four bands. An arm’s length: the wall blade, the corner of a wardrobe, the beam over the pillow, the faults a body registers directly, as an edge at the shoulder or a weight over the head. The room: the door in line with the window, the desk in the corridor’s line, the stair landing at the door, the faults of draught and sight line, felt as the watched door. The street: the road running at the house, the road curving away, the corner across the road, seen and heard as headlights, engine noise and exposure, and answered by a hedge. The skyline: the slit between two towers, the edge of a block, the pylon on the hill, which nobody feels who has not been told to, and which the site treats as a matter of view. The tradition uses one word for all four bands; the evidence thins with every band outward, and the drawing says where. The bands are the site’s judgement, not the manuals’: the manuals treat the four ranges with the same word and the same alarm. Inside a room the case is perceptible; at the skyline it is a picture, and a picture is answered by a hedge or a curtain for the view’s sake, which the outside page draws.

The catalogue sorts itself by distance, and the sorting is the most useful thing that can be done with it. At an arm’s length from a sleeper or a sitter are the faults a body registers directly: the edge of a wall or a wardrobe at the shoulder, the beam over the pillow. At the scale of the room are the faults of draught and sight line: the door in line with the window, the desk in the corridor’s line, the stair that lands at the door. At the scale of the street are the faults that are seen and heard, the road running at the house, the road curving away, the corner across the road. And at the scale of the skyline are the faults the modern city added, the slit between two towers, the edge of a block, the pylon on the hill, which nobody feels who has not been told to. The tradition uses one word and one alarm for all four bands; the evidence, taken below, thins with every band outward, and the drawing says where.

The catalogue

Fig. 02 The named faults on one sheet. Above, four that stand outside the house: a road running at the door; a road that curves away with its back to the house, the reverse bow; the pointed corner of a neighbouring building aimed at a window; and the slit between two towers, the sky-cut. Below, four inside: the door in line with a window, the through-house; a beam across a bed; a wall’s edge in line with a bed, the wall blade; and a stair that lands at the entrance. In each the ghosted arrow is the line the tradition reads, and the solid shape is what it is aimed at. Every sha in the catalogue is a line, an edge or a gap aimed at a place where a body rests or arrives. The names are the manuals’, Chinese first and English after; the drawings are the site’s, in the notation used everywhere else on it.

The sheet is the site’s selection from a longer list. The manuals differ on how many sha there are and on their names; Too and Wong each give a dozen or more, Skinner fewer, and the Hong Kong practitioners Bruun and Emmons describe have a vocabulary for the city, flyovers, lift shafts, glass curtain walls, the escalator running at a door, that the older manuals do not need. The eight drawn are the ones that appear in every list and that a reader can check against their own street and plan.

Outside the house

The four exterior sha are the four ways a city can point at a house. A road running straight at the door, the head of a T-junction or the end of a long drive, is the oldest and the clearest: qi charges down it, in the tradition’s reading, and the manuals want a hedge, a wall, a change of level or a turn in the path before the door. A road that curves past the house with its back to it, the reverse bow, is the opposite of the embracing curve the Form School wants in a watercourse; the road’s outer edge is read as a blade drawn across the front. A pointed corner, of a neighbouring building or a wall, aimed at a door or a window, is the corner sha that also has an indoor version. And the narrow slit between two tall buildings, when it faces the house, is the sky-cut, the fault the modern city invented, read as a channel of wind and a line of pressure. The landform texts had a fifth, older than all of these: the water mouth left open, the corner of the site where the stream and the view run out unscreened, and the outside page gives it its garden form.

Inside the house

The four interior sha are the same reading at the scale of a room. A door in line with a window or a back door, the through-house, lets qi and attention run straight in and out, and wants a screen, a plant or a curtain across the line. A beam over a bed, a desk or a seat presses on whoever is under it, and wants the bed moved or the beam hidden. The edge of a projecting wall or a column in line with a bed is the wall blade, and wants a plant or a piece of furniture to blunt it. And a stair that lands at the front door pours the house’s qi toward the street, and wants a turn, a landing or a screen, or in a house still being planned, another place for the stair. The beams and corners guide draws the remedies for the first three in order, and the hallways page the fourth.

The one rule under them

The rule explains why the manuals’ lists grow and never contradict each other. A new kind of building makes a new kind of line, and the practitioner names it; the reading does not change. It also explains why so many of the faults are felt before they are named. A bed under a beam, a desk with a corridor running at it, a front door at the end of a road: nobody needs the tradition to tell them that these are uncomfortable, and the tradition’s contribution is to say why they are all the same discomfort.

What the research can say, band by band

The remedies

The eight faults of the catalogue, answered one by one, with the same three moves:

Fig. 03 The eight faults answered. The ghosted arrow is still the line from the catalogue; the solid additions are what the tradition puts in its way. Outside: a hedge across the road’s line with the path bent round it; a row of planting along the reverse bow; a curtain on the window and a plant in the line of the pointed corner; a tree between the slit and the house. Inside: a screen a step inside the door of the through-house, so that the path bends; a false ceiling under the beam where the bed cannot move; the bed moved off the wall blade’s line and a plant at the edge; a screen and a rug at the foot of the stair. Under each, which of the three moves it is. The remedies are the manuals’ and there are only three of them: interrupt the line with something that stands in it, turn the body off it, or move the thing it is aimed at. The bagua mirror the shops sell for the road and the corner is not drawn: it interrupts nothing, and the tradition that recommends it is the popular one, not the classical.

Checklist

Stand at the door and look out: a road, a corner, a post or a slit between buildings aimed at you is a sha to interrupt
Stand at the door and look in: a window or a back door straight ahead is the through-house
Lie on the bed and look up: nothing across the ceiling over your head
Lie on the bed and look along it: no wall’s edge, column or corner in line with you
Sit at the desk: nothing pointed at you from the room, and the door where you can see it
Weigh the fault by its range: an arm’s length and the room first, the street second, the skyline for the view
Interrupt the line first, turn the object second, move the person last
Hang nothing on the door that is aimed at a neighbour