The short answer
A luopan combines a compass bearing with rings of traditional correspondences. First establish a reliable direction and what that direction refers to. The rings organize a reading; they do not compensate for an unknown bearing or missing information about the building.
An instrument and a reference system
Historical museum records describe the Chinese geomantic compass as a compass surrounded by graduated interpretive markings. Different luopan designs contain different rings. The presence of many rings should not be read as many independent measurements of a room; much of what surrounds the needle is a system of correspondences.
Background: Smithsonian — Descriptive Catalogue of Chinese Religious Objects (1921)
Eight directions are a coarse partition
The familiar North, North-East and other compass sectors each cover 45 degrees. The twenty-four mountains subdivide the circle into 15-degree bands. A bearing near a boundary can therefore matter differently to a detailed compass method than to an eight-direction overview. The method’s required resolution should be stated before a reading is trusted.
House Quest stores a plan-up bearing and shows the corresponding directional layer. A floor plan imported as a tracing image supplies a shape, not necessarily a measured North. Rotating the image or the screen is not the same thing as confirming a real-world bearing.
Magnetic North and plan-up are not interchangeable
A phone reading can be disturbed by nearby metal or electrical equipment. Repeated measurements away from obvious interference are more informative than one reading beside a desk or appliance. If a method uses a different North convention, record that convention rather than silently substituting a value.
For the editor, identify which real direction corresponds to the top of your plan. Then enter and confirm that bearing in the compass panel. An unknown direction should remain unknown. A neat-looking overlay produced from a default zero is not evidence that the building faces North.
More detail does not remove missing information
A building reading may also depend on its sitting and facing directions, how the main entrance is understood, and the particular lineage being used. Those are interpretive and site-specific choices. They cannot all be recovered from the fact that a phone can display a compass number.
This guide explains how to read the input, while the interactive Bagua page demonstrates the chosen mapping. The decorative compass on the homepage is useful for learning directional associations. It does not take a sensor measurement, locate your home or substitute for a site survey.
| Level | What it tells you |
|---|---|
| A bearing | An angle under a stated North convention |
| Eight directions | Eight sectors of 45° each |
| Twenty-four mountains | Twenty-four bands of 15° each |
| A luopan ring | A named tradition’s correspondence table |
Your plan points 30 degrees: record what the number means
Take a floor plan whose top edge points toward a bearing of 30 degrees from North. The plan’s upward direction is therefore north-eastward, even though the drawing itself is displayed upright. If you enter a default zero instead, the directional overlay will treat plan-up as North. Furniture can remain in exactly the same screen positions while receiving different sector labels, because the orientation input has changed.
Before confirming the value, record how it was obtained. A printed North arrow, a site survey and a phone compass may not use the same reference convention. A phone reading taken beside a large appliance should be checked in a less disturbed position. Repeating a reading also helps expose a disagreement that a single precise-looking number can conceal. This is a record of your measurement process, not a claim that this article calibrates the instrument.
Separate plan-up from building facing. A drawing’s top edge may correspond to a side wall rather than the entrance or the direction a practitioner considers the building to face. For an indoor overlay, establish the relationship between the drawing and North. For a building-specific method, ask which facing definition and additional inputs it needs. Entering one compass number does not make those separate choices disappear.
A way to work through it
- Identify the actual bearing of the plan’s top edge; keep its source and North convention with the plan.
- Compare repeated readings away from obvious interference, and resolve substantial disagreement before confirming the direction.
- Use the confirmed plan bearing for the indoor map; record any building-facing interpretation as a separate input.
Try an observation
Compare two readings of the same real direction away from metal furniture, then mark that direction on a simple plan. Keep the measurement and the interpretive method as separate notes.
Common questions
Can I use a phone instead of a luopan?
A phone can help obtain a compass bearing, but its settings, calibration and nearby interference matter. It does not reproduce every interpretive ring of a luopan. Check the direction reference and repeat the measurement; a displayed number alone is not a complete Feng Shui reading.
What are the 24 mountains on a luopan?
They subdivide the compass circle into twenty-four bands of 15 degrees. The eight broad directions instead cover 45 degrees each. A method that uses the finer partition needs a correspondingly clear bearing and boundary convention; the two resolutions should not be silently substituted.
Is the direction of the front door the same as building facing?
It may be used that way in a particular reading, but the terms should not be assumed identical. A building-specific method can define facing using site features beyond the apartment door. Ask for the definition before comparing two charts that claim to describe the same property.
Why does rotating my plan change the direction overlay?
Screen rotation and real-world bearing are different operations. An overlay needs the relationship between plan-up and North. If the drawing orientation changes, that relationship must remain consistent. A decorative compass image or the top of a screenshot cannot establish the building’s direction.
Sources & further reading
- Smithsonian — Descriptive Catalogue of Chinese Religious Objects (1921)
Historical museum description of a geomantic compass; dated terminology should be read critically.
Historical and traditional interpretations are distinguished from observable layout conditions. Worked examples are illustrative editorial scenarios, not documented client cases. Practical examples and product-scope explanations are editorial applications, not quoted source text. School conventions vary; these articles do not predict health, wealth or personal outcomes.