Is it safe to enter a tri party agreement with home loan

Who is the third party to the agreement? What is the requirement to include third party? What is the purpose of subject agreement?

Incomplete information cannot lead to form an opinion and advise you properly. It would be better to consult a local prudent lawyer for proper appreciation of facts and circumstances, analyse, guide and proceed.

the perpose of including third party should be clear.

There is nothing wrong in entering into a tri-partite agreement with the builder, previous buyer. 

The terms and conditions should be transparent. 

In the event of any doubt or fictitious about any terms or conditions, you may consult a local advocate before signing the papers.