Will every map have a 10-degree tilt with North at the top?
No. Each map has its own tilt, 10, 12, 20 or 25 degrees, and North can be on any side. Measure the tilt with Google Earth and find which side is North at the site, from the client or from the North mark that most plans carry, although the tilt itself is not written on them.
Related questions
If Google Earth shows 350 degrees, how should North be marked on the plan?
In a regular plot you can set the zero directly at 350 degrees when drawing the straight line. It is easier to think of it as a 10-degree tilt and set off 10 degrees, because that method works from whichever side of the plot you start.
My compass showed North tilted toward the North-East, and Google Earth showed 2.39 degrees. Is that also toward the North-East?
Not necessarily. A magnetic compass shows North directly, so its reading can be stated straight away, for example North 30 degrees toward East. Google Earth and the mobile app only show the heading of the line you draw, and North has to be worked out from it; a heading of 2.39 means North lies 2.39 degrees to the left.
Should directions now always be read by degrees?
Yes, always by degrees; reading directions without degrees was a mistake, and only the degree method shows the actual zones.
Why does each outer devta cover 11.25 degrees, and how are the pads marked?
The 32 devtas of the pishach bhoomi share the full 360 degrees, and 360 divided by 32 is 11.25. Mark North with the plot's actual tilt (for example 5 degrees), place Som devta centred on North with 5.625 degrees on each side, then mark every further 11.25 degrees with a protractor or a zoning chakra and draw those lines only in the outer ring. The 12 inner devtas follow an 18-54-18 degree split in each direction (27 degrees on each side of the direction line for the middle one), and Brahma sits in the centre.
At what degree do the corner directions (vidisha) fall?
North-East, South-East, South-West and North-West fall exactly 45 degrees from the main directions. Where they fall in your own flat becomes clear once you do the zoning.
Does everything taught today also apply to an apartment or flat, or only to a kothi?
Everything taught today applies to flats as well, except bhoomi vibhajan. In a flat it is already done: the space left around the building during construction is its Pishach bhoomi. Ati marma, zoning and directions all apply inside the flat.