Thank you to everyone who gave inputs.

As per Sir Andoy's advice, I called up ERC today regarding my situation. In summary, Meralco cannot require me to pay out a single centavo for new lines or facilities. Below is an excerpt from the Distribution Services and Open Access Rules (DSOAR) of the ERC.

2.6
MODIFICATIONS AND NEW PHYSICAL CONNECTIONS:
RESIDENTIAL

2.6.1
RIGHT TO EXTENSION OF LINES AND FACILITIES
In accordance with the Magna Carta, a residential End-user located within thirty (30) meters from the distribution utilities’ existing secondary low voltage lines has the right to an extension of lines or installation of additional facilities, other than a service drop, at the expense of the utility. However, if a prospective customer is beyond the said distance, the customer shall advance the amounts necessary to cover the expenditures on the facilities beyond thirty (30) meters.

Full document can be viewed at this link below for those interested:

https://www.doe.gov.ph/doe_files/pdf/Researchers_Downloable_Files/DownloadableFiles/DSOAR.pdf

Then I found an article featuring reporting on important amendments to the DSOAR 2 years ago with an excerpt below:

For one, ERC clarified that cost of installation or extension of lines and facilities that are included in the distribution utilities (DUs) capital expenditures program must be shouldered by the DUs.

“This is regardless of the location of the electricity consumer requesting line facilities in the DU’s franchise area,” ERC said.

“Electricity consumers, both residential and non-residential, will have their requests for lines and facilities acted upon accordingly, without any cash outlay, regardless of their location within the franchise area since the DU will shoulder the costs for as long as the project is viable,” Ducut said.

Prior to the amendments, the right to extension of lines and facilities for residential customers is limited within 30 meters from the DU’s secondary voltage lines and the excess thereof shall be advanced by customer to cover the expenditures.

Link to the news report below:

ERC amends rules on new connections for power users | Business, News, The Philippine Star | philstar.com

So I will try to use these documents to work it out with Meralco.

Update you guys if I have news.

Thanks!