Is the brochure's North arrow right? How to check it

Treat the arrow as a starting point. A brochure is a marketing document. The RERA Act requires a promoter to file the sanctioned plan with the authority and to make the sanctioned plans available at booking (ss. 4(2)(d) and 11(3)(a)) [1]. The sections we read set no standard for how a North arrow is drawn in a brochure.

So check it. The satellite map gives you the building's outline against true North. The compass gives you magnetic North on site, and in Mumbai, Delhi and Bengaluru magnetic and true North are within about 1.3 degrees of each other [2]. The sanctioned plan, if it carries a North point, is a third reference. If all three agree within a few degrees, trust the arrow. If they do not, use the satellite bearing.

An arrow can be wrong for ordinary reasons. It may be drawn for the whole site layout rather than for your unit's page. It may be drawn square to the page when the tower sits at an angle to the road. The unit plan may have been flipped for a mirror-image unit without the arrow being flipped too. And a designer may simply have drawn it by eye.

None of this needs bad faith. The point is that an arrow on a sales sheet has not been checked by anyone who must answer for it. The plans the law cares about are the sanctioned ones, which a buyer is entitled to see (RERA s. 19(1)) [1].

Small errors matter because zones are narrow. The 16-zone school uses zones of 22.5 degrees and the 8-direction school uses 45 degrees [3]. Our guide to 16-zone and 8-direction Vastu gives every zone in degrees.

A satellite map is the most reliable reference you can get without a surveyor. It shows the real outline of the tower against geographic North.

1. Open a satellite map and find the exact tower. In a large project, confirm the tower by its shape, the road and the gate.
2. Reset the view to north-up and flat. Google's Earth help explains that clicking the up arrow on the compass returns the view to north-facing, and that the view can be tilted, so flatten it before you read an angle [4].
3. Line up a long outer wall of the brochure plan with the same wall of the building.
4. Read the angle between that wall and North on the map, then do the same on the brochure using its arrow.
5. The difference between the two angles is the arrow's error.

Vastu16's check does this for you: you place the plan over the satellite image and it sets North from the map [3].

A phone compass gives magnetic North, and steel disturbs it. A 2023 study in Sensors notes that phone magnetometers pick up local disturbances from electronic devices and steel reinforcement in buildings [5]. Apple's documentation says the reported heading can be invalid near strong local magnetic fields, and that calibration only removes fields that move with the device [6].

Take the reading properly:

1. Stand near the centre of the flat, at least a metre from columns, railings, appliances and almirahs.
2. Calibrate the phone by moving it in a figure-8, as Android's sensor guide suggests [7].
3. Hold it flat, screen up, and read the bearing of one long wall three times, a step apart.
4. If the readings differ by more than 10 degrees, move and try again. Vastu16 rejects compass readings more than 10 degrees apart [3].

In Mumbai the declination is about 0 degrees, in Delhi 1.3 degrees east and in Bengaluru 1.1 degrees west, per NOAA's World Magnetic Model 2025 [2]. Our Vastu compass shows the heading and its zone.

The sanctioned plan is the one with legal weight. Ask the builder for it at booking; the Act requires sanctioned plans to be made available (s. 11(3)(a)) and gives an allottee the right to that information (s. 19(1)) [1]. In Maharashtra, the MahaRERA portal lets anyone search a registered project before booking [8].

If the sanctioned plan or the site layout plan carries a North point, compare it with the brochure. Look for three things: the same North on both, the same unit orientation, and the same tower position on the site. A mismatch between brochure and sanctioned plan is worth raising in writing.

This is general information, not legal advice. Check your state's RERA rules or ask a lawyer.

Our post on magnetic North and true North explains why the compass and the map can differ, and when it matters.

Use this table on site. It assumes the brochure arrow differs from the satellite bearing by the error shown [3].

Vastu16 rates North confidence high when the satellite match and the compass agree within 8 degrees, medium between 8 and 15, and low beyond 15 [3]. NOAA notes that local magnetic anomalies of 3 to 4 degrees are not uncommon, which is why the compass alone is not enough [9].

Tradition

• The classical texts oriented a site by marking where a pole's shadow touches a circle drawn round it, in the morning and in the evening, not by a compass: Mayamata ch. 6 [10].
• Zone widths of 22.5 and 45 degrees: Vastu16's rule table for the two schools [3].

Physical and legal fact

• Declination is the angle between magnetic and true North: NOAA [11].
• Indian city declinations: NOAA World Magnetic Model 2025, via Vastu16's table [2].
• Steel reinforcement disturbs phone magnetometers: Sensors 2023 [5].
• Sanctioned plans must be made available at booking: RERA Act 2016, s. 11(3)(a) [1].

Our free tool lets you verify North and check the flat under both schools. You place the brochure plan over the satellite image, add compass readings if you have them, and the report shows a North confidence level with each room's zone. It flags rooms within 5 degrees of a zone line. It cannot tell whether a brochure plan matches what will be built. Our methodology page explains each step.