अशक्तो विंशतेरूर्ध्वं कारयेच्छक्तितस्तदा विष्कम्भपर्वतांस्तद्वत् तुरीयांशेन कल्पयेत् //
aśakto viṃśaterūrdhvaṃ kārayecchaktitastadā viṣkambhaparvatāṃstadvat turīyāṃśena kalpayet //
যদি কেউ বিশ (একক) অতিক্রম করে করতে অক্ষম হয়, তবে সামর্থ্য অনুযায়ী করাবে। তদ্রূপ বিষ্কম্ভ ও পর্বত-অংশগুলিও চতুর্থাংশ অনুপাতে নির্ধারণ করবে।
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.