1) draw the whole house including the renovated area ..
2) the drawings highlighted in red (new area extension will be calculated )
Example :  ground floor - rm 14 for every 9 msq and 1st floor rm 12 for every 9msq

Payment to MPaJ is something like this
Minimum - gfloor rm140 and minimum f.floor  rm120 - plan processing fee
Penalty pemutihan -  penalty imposed 10x amount of process fee plan
Total 140+120 : rm260 x 10times : rm 2600.00. ( this is last time I did ya for one of my clients ) plus few rm++ for MPaJ digital scan …
The rest are those forms and consultants to finish up and endorse..and the consultants fee

But make sure house is within the boundary line … if still the  house is within boundary line still ok.. if exceed boundary then need to demolish or dismantle the exceeded area …. Boundary line ya not Buidling setback ….

Hope this help
Cheers mate
Izwan
Www.archidstudio.com