It is true, DBKL is very fussy. It took me 3 months to finally get my approval.

DBKL fees should be around 3.5k. Bulk of that is for deposit. It is 2k, and it is very difficult to get your deposit back. They will make it difficult for you. Any slight non-conformance means byebye deposit. 1k would be for Alam Flora dustbin (2 big, 1 small).

Architect fees, depend on how extensive the renovation is. Probably less than 2k for your renovation. Double storey extensions cost much more.

Usually, contractors like to quote a lump sum. Architect + DBKL + whatever bribe to make things go smoother. If a contractor suspiciously quotes too little, it is probably his fees + the bribe he gives DBKL. Ask him for proof of payment for every step, see if he can produce. DBKL issues some form of letter for every step of approval. If you don't mind not following the letter of the law, I guess it's fine.

RM 50 renovation booklet not available for DBKL anymore. You will need to engage the services of a DBKL-approved architect.

There are always people going for the bribery route. But if you want to be safe, just submit the plan. Worst case is someone in your neighbourhood really hates you, and goes all the way to have your illegal extension torn down.

Let's see, you should have a floor plan and a roof plan ( both of these in one sheet. It will also contain door and window schedules ). If you have additional toilet, or move existing ones, you will have a sewage plan. If you need extra pile caps, footings, structural works, you will need an RC plan and this would require an engineer's approval ( and more money ). If you are doing earthworks ( such as leveling floor area, etc ), you will need earthworks plan. $$$