My advice. Dont be too calculative. U willing to spend huge money on renovation. eletric the most important part. Anything wrong with wiring ur house will burn down cause of short circuir. Get licence contractor. Their price higher than normal indon or bangla guy or unregistered contractor. But u know u r safe . Because to certify test for new installation u need to run 3 test. Insulation test. Continuity test and earth resistence test.
Pricing are difference for everyhouse. We calculate the wire run from db box to point. 1 poinr from db to kitchen took 5 ' from ceiling to db 40' up ceiling and 10 ' down to plug point. Its took 50' wire lenght x 3 (life neutral n earth wire) 150' same 50m. 1 megacable cost u RM80 for 100m. 50m cost u RM40 not include cost of hacking plastering piping and labour cosr finally socket with difference brand like clipsal mk pdl and some cheap brand. So my advice pay the contractor the right price with their effoct and their experience and qualification.tq

If u really want to follow the regulation 100% than u have to spent more. Normally we follow basic safety requirement. For aircond individual line from db to point no sharing. 2.5mm max for 2hp still okay. Above 2hp to 3hp require 4mm amd so on......for power socket normal loop 2 to 3 just normal use...tv hifi dvd stand fan...small load. For kitchen 2.5mm for normal freezer rice cooker kettle but not exceedind 13A in total for long period. Oven 4mm required. Water heater prefer 4mm and extra ELCB earth leakage circuit breaker .double storey house prefer 2 db for isolating purposes and control and save on wiring cost. Earthing also important in installation and need to do properly n test.

If u really want to follow the regulation 100% than u have to spent more. Normally we follow basic safety requirement. For aircond individual line from db to point no sharing. 2.5mm max for 2hp still okay. Above 2hp to 3hp require 4mm amd so on......for power socket normal loop 2 to 3 just normal use...tv hifi dvd stand fan...small load. For kitchen 2.5mm for normal freezer rice cooker kettle but not exceedind 13A in total for long period. Oven 4mm required. Water heater prefer 4mm and extra ELCB earth leakage circuit breaker .double storey house prefer 2 db for isolating purposes and control and save on wiring cost. Earthing also important in installation and need to do properly n test.

Im licence eletrical contractor. Normally i charged cliemt base on total material cost plus labour cost plus transport charges and get some reasonable profit.not necesarry base on points. Because im the boss and im the worker too. As long as i got job got salary for my staff and retain some profit for tax. That emough for me. So i agreed. It s depend to individual. Regardless of u r chiness malay or indian. U cant say others not good. Itd win win situation. U sabe budget we got business.