Solar panels in Castle Hill

As an estimate, a 6.6kW system starts from $7,410, a 10kW system starts from $10,300 and a 13.2kW system starts from $11,250 (with battery prices starting from $4,290), with the STC discount for postcode 2154 already taken off (incl. GST for metro areas; regional areas subject to freight and travel costs). Those are starting estimates for a straightforward install, not a fixed price. Two things push a Castle Hill quote above them more often than elsewhere: two-storey access, and a large home where the sensible system is 13.2kW rather than 6.6kW because the pool pump, the ducted system and an EV are all on the same bill.

Castle Hill is in STC Zone 3, rating 1.382. In 2026 a 6.6kW system creates 45 certificates, worth roughly $1,710 off the price, and a 13.2kW system 91 certificates, roughly $3,458. The discount shrinks each January until the scheme ends in 2030, and the exact amount depends on the certificate market on your installation date.

Often yes, and there is a lot of it around the Metro corridor here. The question is never really technical, it is about who owns the roof. In most strata schemes the roof is common property even though the townhouse underneath is yours, so an individual lot owner cannot simply install on it — you need the owners corporation's approval, usually by resolution at a general meeting, and a by-law recording who maintains the system and who pays if the roof needs work later. None of that is exotic; it just takes longer than a free-standing house. We are happy to provide the technical detail a strata committee needs to make the decision.

Yes, and it is often the better project. A scheme-owned system on the common roof can run common-property loads — lifts, lighting, pumps, car park ventilation — which cuts the levies everyone pays rather than one household's bill. It is a bigger conversation because it involves the owners corporation's budget and metering, and sometimes a single larger system serving several buildings. We quote those as commercial work rather than as a home install, because that is genuinely what they are.

The distribution network that owns the poles and wires in your street approves it — not your retailer — and we lodge the application for you. That network also decides how much your system may export: on a flexible export connection, eligible customers can send up to 10kW per phase back to the grid most of the time, while a fixed export limit caps exports at 1.5kW. Larger homes here are often three-phase, so that allowance applies per phase, which is what makes a 13.2kW system practical.

For a house, usually not — in NSW most rooftop solar is exempt development and needs no development application from The Hills Shire Council. Strata is the difference that matters here: your owners corporation's approval is a separate requirement from council's, and getting one does not get you the other. Heritage-listed properties are the other exception, and we check that before we quote.

Sometimes, and it is a fair question on a street where it matters to people. Where the roof allows we put the array on a rear or side face, which often costs a little generation and buys a lot of goodwill. Where the only worthwhile sun is on the front face, we will show you the layout and the difference in output before you decide, rather than making that call for you.