Recommended Construction Sequence for Basement in RCC Buildings – Columns vs Retaining Walls First and Impact on Curing and strength

[ananthp]

I am currently constructing a residential building where am raising basement from NG level and would like clarification on the correct construction sequence for the basement level in an RCC framed structure. I haven't started construction yet but hinting for good contractor

Some contractors have suggested that for the basement portion, the retaining wall (brick/block masonry) should be constructed first after excavation and PCC, and then the RCC columns should be cast later. Their reasoning is that building the wall first helps with soil consolidation and stability after backfilling.

However, my understanding was that the typical structural sequence is to cast RCC columns first (from footing/pedestal) and then construct masonry or retaining walls as infill.

I also have a concern regarding the curing and bond quality if masonry is constructed first. If the wall is built before the column, it will likely cover three sides of the column location, leaving only one face accessible. When the column concrete is poured later:

• Proper curing of the column surfaces on the three enclosed sides may not be possible.
• The brick/block masonry and mortar may absorb moisture from the fresh concrete, potentially affecting hydration and strength in those areas.
• It may also create difficulties in compaction, alignment, and proper formwork.

Given this, I would like to understand from experienced structural engineers:

1. What is the recommended construction sequence for basement levels in RCC framed buildings — columns first or retaining walls first? for this qork alone most of the builders are construction the wall first and then column later
2. Is constructing masonry/retaining walls before columns ever recommended, and under what conditions?
3. Could this approach negatively impact curing, bonding, or structural performance of the column?

The project is a residential RCC framed building with a stilt level and stilt will be 3 feet from NG level, and I want to ensure the construction follows sound structural engineering practices.

Any guidance or references to standard practices would be greatly appreciated.

reference image is below, this is from YT but most contractors follow this practice