Dear Keerthi ji,
What you heard is not 100% correct.
Your office is covered under ESI if there are 10 / 20 and more employees working. Now there are only three states wherein the threshold limit of coverage of establishment is 20.
As regards to your construction sites, I will not say that your construction site is totally excluded or exempted from ESI coverage.
You need to read ESI circular 4/99 dated 14.06.1999 very carefully and interpret it correctly. The wordings in the said circular says, " hence, the following actions may please be taken for coverage of construction agency / offices of the builders". If you read this circular again and again in between the lines, to my view, you can not keep your construction site out of ESI. You can keep only construction workers (i.e. construction helpers who are not regular one) out of ESI.
There are lot of ambiguities on this subject.
In ESI Act, there is no exclusion of any Industries. My question to experts, can such circular change the law?
But it is a fact or it is a practice in Construction Industry that construction sites are excluded from ESI coverage. This fact / practice is also accepted by the Corporation / Government.
Recently I came across the ESI Corporation covering Construction sites on the basis of installation of batching plant (RMC) at sites.
I also came across some cases in which Corporation demanding ESI dues on Construction workers. Now you will understand what I said above.
My view on this subject was different earlier, that I accept here. But now I am enlightened ..........