House Rewiring & Renovation Electrical Guide

The biggest drivers are the age and construction of the home. A 1990s brick-veneer with accessible roof and subfloor space is quick to rewire; a 1920s double-brick semi with plaster ceilings and no subfloor is not. Wall type dictates whether cables can be fished or whether chase-outs and patching are required.

The scope also matters. A minimum-compliance rewire on the existing point count is materially cheaper than a full modernisation with additional GPOs in every room, USB outlets, data cabling, downlight replacements, an EV-ready sub-board, and outdoor circuits. Switchboard condition is the other swing factor — many older Sydney homes need a full board upgrade at the same time.

Access, asbestos in the meter box or eaves, whether the property is occupied during works, and whether you want walls patched and painted after the electrical work all move the number. Rather than publish a range that may not apply to your job, we come out, look at the property and provide a fixed written quote. Get a free fixed-price quote before you commit.

A standard 10A lighting circuit can carry about 2,400W continuous, and good practice is to design to 80% of that — around 1,900W of usable load. For modern 8–12W LED downlights the practical ceiling on a single circuit is very high, so wattage is almost never the limiting factor in a residential rewire.

What actually limits downlights per circuit is zoning. Under AS/NZS 3000 every lighting circuit needs RCD protection. If every downlight in the house sits on one RCD, a single fault leaves you in the dark. Most Sydney electricians split a 3–4 bedroom home into 2–4 lighting circuits — typically living areas, bedrooms, wet areas, and outdoor/security — so RCD trips are contained.

Fitting choice also matters. Non-fire-rated downlights must maintain clearance from insulation and structural timbers; IC-4 or CA-rated fittings can be covered by insulation. Your electrician will size and zone the circuits to the actual floor plan, not just the total wattage.

Bring the electrician in at the design stage, before the builder locks in the wall linings. That's when decisions about switchboard capacity, mains upgrades, downlight positions, data cabling, EV-ready sub-boards, and lighting control are cheapest to make. Retrofitting a data cable after gyprock is on costs 3–5x what it costs during first-fix.

The typical sequence is: site inspection and fixed quote → first-fix (rough-in of cables before walls are lined) → coordinated inspections with the builder → second-fix (fitting off switches, GPOs, downlights and appliances after painting) → switchboard changeover and Ausgrid isolation if required → testing, CCEW and handover.

Ask any electrician you're considering to show their NSW electrical contractor licence, their public liability insurance certificate, and a sample CCEW from a recent job. Empire is a licensed NSW electrical contractor and issues a CCEW on every renovation — book a design-stage consult to lock in scope before the builder starts.