Customers renovating a house often assume solar is a later problem. It is the opposite: renovation is the moment when preparing for solar costs almost nothing, and once the ceilings and walls close, the same work becomes disruptive and expensive.
What to do now, while it is open
- Run the DC conduit from roof to inverter position. Once the ceiling is boarded, this becomes a chase-and-patch job.
- Decide the inverter location. It wants shade, ventilation and reasonable proximity to the main board. A garage or utility wall is usually right; a west-facing outside wall in full sun is not.
- Leave spare capacity at the distribution board. A solar system needs its own dedicated way. Finding there is no room later means changing the board.
- Confirm your supply phase before the electrician finishes. If you are single phase and will want more than 7.44 kWp, the moment to think about a three-phase upgrade is now, not after the walls are painted.
- Photograph the roof structure before it is covered. Rafter spacing and condition decide the mounting method. Photos taken now save a survey argument later.
- If you are re-roofing anyway, tell us. Mounting into a roof that is already open is materially simpler than retrofitting onto a finished one.
The honest problem: we cannot size your system yet
Solar sizing works backwards from your electricity consumption. If you have not lived in the house, there is no consumption to work from — no TNB bill, no usage history, nothing to model savings against.
We will not invent one. A savings figure derived from a guessed bill is a number we cannot defend, and you would be making a five-figure decision on it. What we can do instead is work from expected load: how many air-conditioning units, whether there is electric or solar water heating, whether an EV charger is going in, and how many people will live there. That gets us to a sensible range and, importantly, tells us whether you need three phase.
Why phase matters more for a new house
Under Solar ATAP §8.1 a single-phase domestic supply is capped at a 5 kWac inverter, which means 7.44 kWp is the largest system you can install. Three phase raises that to 15 kWac.
A renovated house with several air-conditioners, a water heater and an EV charger can comfortably exceed what 7.44 kWp will offset. If that is your plan, the phase conversation belongs in the renovation, when the electrician is already on site.
Timing against the SuRIA rebate
The SuRIA Home rebate pays RM600 per kWac up to RM3,000, but the system must be commissioned with TNB by 31 December 2026. Installations take roughly six to ten weeks from booking to TNB commissioning, so work backwards from that date rather than towards it. The allocation is also fixed and first-come-first-served, which is a more real constraint than the deadline itself.
You pay us the full system price. There is no customer application: TNB notifies eligible customers, and the government pays the rebate to the TNB account holder after commissioning. It is not a discount we deduct.
The sensible sequence
- Share the roof plans and main board details while the house is still open, so the system can be sized correctly.
- Pre-wiring and conduit go in with the rest of the electrical work.
- You move in and we take one or two real TNB bills.
- We size the system against actual consumption, not an estimate, and install.
This order removes every guess from the sizing.
