अशक्तो विंशतेरूर्ध्वं कारयेच्छक्तितस्तदा विष्कम्भपर्वतांस्तद्वत् तुरीयांशेन कल्पयेत् //
aśakto viṃśaterūrdhvaṃ kārayecchaktitastadā viṣkambhaparvatāṃstadvat turīyāṃśena kalpayet //
विंशत्यधिकं कर्तुमशक्तः सन् शक्तितः कार्यं कारयेत्; तथा विष्कम्भपर्वतान् तुरीयांशेन सम्यक् कल्पयेत्।
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.