Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 9 · Vastu, Griha Pravesha
वास्तु गृहप्रवेशश्च
विस्तार आयामगुणो गृहस्य पदमुच्यते ।तस्माद्धनाधनायर्क्षवारांशाः संख्यया क्रमात् ॥ ५६३ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 563.
Breadth multiplied by length is called the area of the house. From it come six figures, by number, in order. They are the gain, the debt, the aya (the eight directions points), the star, the weekday and the part.
Simple meaning: Multiply breadth by length to get the area. Six figures are worked out from it.
धनाधिकं गृहं वृद्ध्यै ऋणाधिकमशोभनम् ।
A house with more gain than debt is good. An odd aya point is good; an even one can bring poverty.
धनक्षयस्तृतीयर्क्षे पंचमर्क्षे परः क्षयः ।
From the owner's star, the house's 3rd star may cost wealth, the 5th more, the 7th risk the owner's life.
द्विर्द्वादशो निर्धनाय त्रिकोणमसुताय च ।
Owner and house signs 2-12 apart may bring poverty, 5-9 difficulty having sons, 6-8 risk to life. Others are good.