purvam bhumim pariksheta paschaat vaastu prakalpayet ||

first test the earth (site); after that plan construction.

valmikena samayukta bhumirasthiganostu ya ||
randranvitha cha bhurvarjya gatighescha samanvita ||

land with ant hills, skeletons, full of pits and craters should be avoided

varnagandharasakaradishabdasparsanairapi|
parikshyaiva thathayogyam gruhniyaad dravyamuttamam ||

after examining the colour, smell, taste, shape, sound and touch (of the soil) buy the best material as found suitable,.

yavattatra jalam drushtam khanettavattu bhutale |

Till water is seen there (one) should dig the ground.

Ratnimaatramadhe garte parikshya khatapurane ||
aadhike sriyamapnoti nyune haanim same samam ||

it,(soil) should be tested by digging a pit of 1 arm length and refilling it (with the same soil). if (soil) is more, one wil beget prosperity; if short, one wil beget loss; if equal, it is normal.



source : matsya puranam, Adhyayah 253, slokah 11.(puranic period)
vastu puranam, slokah 5, viswakarma (6th century AD).
Bhrugu samhita, Adhyayah 4 (post vedic period)
kasyapa silpah, adhayah 4, (post vedic period)