In case it helps, here are the sanitary drainage articulation notes from the Soil Test and Foundation Design report. It states that vertical expansion joints are required only when pipe depth exceeds 6 meters, which I do not believe is the case here. However, I am not sure if there are code requirem...

Who designed the house? The house was designed by the builder, Coral Homes. However, they didn't have access to the sewerage plans until well after the contract was signed and after the settlement of the land. It appears the house connection was installed quite late. Nevertheless, it seems that the...

Please refer to the attached image of lot 7. The invert level of the house connection for gravity sewerage is 38.066, while the rest of the lot is approximately 38.8. Accounting for 400mm for the drain head and another 400mm for swivel and expansion joints (as the site is classified E2), this leaves...