अशक्तो विंशतेरूर्ध्वं कारयेच्छक्तितस्तदा विष्कम्भपर्वतांस्तद्वत् तुरीयांशेन कल्पयेत् //
aśakto viṃśaterūrdhvaṃ kārayecchaktitastadā viṣkambhaparvatāṃstadvat turīyāṃśena kalpayet //
Se alguém não puder executar (a obra prescrita) além de vinte (unidades), então deve fazê-la conforme a sua capacidade. Do mesmo modo, as medidas transversais (viṣkambha) e as partes elevadas (parvata) devem ser proporcionadas tomando-se um quarto (turīyāṁśa).
This verse does not address Pralaya; it gives practical Vastu guidance on scaling construction measurements when one cannot follow the full prescribed dimension.
It frames dharmic practicality: a patron (king/householder) should undertake building works within means, maintaining proportional harmony rather than abandoning the project or violating core design ratios.
It authorizes proportional reduction—especially using a quarter-share rule (turīyāṁśa)—for key dimensions like breadth/diameter (viṣkambha) and raised elements (parvata), preserving canonical Vastu symmetry under constraints.