I just want to move the WC, have a double basin, a jacuzzi, a rain shower and hand shower. I'm changing all the ABS piping and adding copper piping for hot water, plus to be connected to a storage water heater. Nothing complicated!

My initial consultation with IDs, what I described was simple. I was quoted RM700 - RM1,500 for these works (refer attached Option 1 & 2).  But when I talked to plumbers to seek for second opinion, it was a different story. I was quoted RM5k - RM8k for these works!  

After a long explanation from plumbers, I was convinced that the IDs might not have the expertise in this area. Just adding copper piping itself costs more than RM1,500.00.

At the end, I dismissed the idea of using an ID or one-stop contractor, and appointed all specialized sub-contractors. Yes, you need to have the bandwidth to project manage them, but at least they are good in their specialized fields. My dad helped me to oversee daily work progress while I had to manage the coordination of the sub-cons. It is a great learning experience and I managed to complete my renovation in 2 months time.