1#重庆人 ( A- W w0 R2 V f/ v+ \7 I e 8 p1 H' O# ~8 H6 X4 a 2 O8 I, w4 i. e* A8 F- iIf the builder is responsible for rough grading and the certificate as per your contract signed, then for sure, your builder has to do whatever needed to get a pass, whether it is a retaining wall or anything else. Talk to your lawyer to find out.