Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 9 · Vastu, Griha Pravesha
वास्तु गृहप्रवेशश्च
एतेष्वेतानि शस्त्राणि स्वं स्थाप्यानि स्वदिक्ष्वपि ।ध्वजो धूम्रोथ सिंहः श्वा सौरमेयः खरो गजः ॥ ५८९ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 589.
In these houses, set these points, each in its own direction. They are Dhvaja (banner), Dhuma (smoke), Simha (lion), Shva (dog), Vrisha (bull), Khara (ass) and Gaja (elephant).
Simple meaning: Seven of the eight direction points are named, each placed in its own direction.
ध्वांक्षश्चैव भवंत्यष्टौ पूर्वादिपाः क्रमादमी ।
The eight points rule the eight directions in order. Plaksha, fig, mango, neem and vibhitaka trees are to be avoided.
ये कंटका दुग्धवृक्षा वृक्षाश्वत्थकपित्थकाः ।
Thorny trees, milk-sap trees, peepal, wood apple and tamarind are to be avoided.
पित्तवाग्रजदेहस्यात्पश्चिमे दक्षिणे तया ।
Houses should have an even number of posts and pillars.