Land owners constructing residential apartment

A group of employees, numbering 34 join together and purchase a 20 cents land through a sale deed where they are all tenants in common.

Now they appoint a contractor to build them the residential apartment for themselves - total 34 flats. Consideration for contractor is in money only

Question is - Is service tax applicable ?

Can they form an Association of Persons for the above purpose and collect the contribution from each member accordingly for each stage of completion

Regards