Renovating Older Homes: Electrical and Plumbing Upgrades to Expect

Services that seemed fine for decades come up for replacement during renovations for three converging reasons.

• Access: With plaster off and floors up, work that would normally require destructive access becomes cheap to reach. This is the once-in-decades window.
• Load and layout: Modern kitchens, induction cooking, air conditioning and bathroom heating push demand far past what old circuits and undersized pipes were designed for, and new layouts put fixtures where services never ran.
• Compliance triggers: Electrical and plumbing work in Victoria must be done by licensed practitioners, and new work typically must meet current standards. Touching old systems often means bringing the affected parts up to standard, commonly including safety switch protection on altered circuits.

None of this means every old home needs full rewiring and repiping. It means the renovation zone, at minimum, usually gets modernised, and the sensible question for the rest of the house is whether to use the open walls while you have them.

The electrical conversation in pre-1980s homes tends to cover a familiar list.

• Switchboard upgrades: Ceramic fuse boards and boards without adequate safety switch (RCD) protection are routinely replaced during renovations. A modern board with circuit breakers and RCDs is foundational to everything else being added.
• Degraded wiring: Very old rubber-insulated cabling, found in some early and interwar homes, is typically replaced on discovery because the insulation becomes brittle and dangerous. Cotton-sheathed and early plastic wiring is assessed case by case.
• Circuit capacity: Modern kitchens commonly need multiple dedicated circuits for ovens, induction cooktops and appliance banks that a single old power circuit cannot carry.
• Earthing and bonding: Older installations may need earthing upgrades to support safe modern fixtures, particularly in wet areas.
• Points and lighting: Quadrupling the power points and moving to efficient LED lighting is standard renovation scope rather than an upgrade.

All electrical work must be carried out by a licensed electrician, who provides a certificate of electrical safety for the work. Keep every certificate with your project records; they matter at sale time and for insurance.

Plumbing in older homes hides its age better than wiring, right up until demolition day.

• Galvanised steel water pipes: Common in homes up to around the 1970s, these corrode internally, restricting flow and discolouring water. Renovations routinely replace them with copper or approved plastics, at least within the works zone.
• Old drainage: Earthenware drains crack and attract tree roots. Renovations that move fixtures often reveal drainage that needs partial replacement or relining.
• Undersized hot water delivery: Long, narrow, uninsulated pipe runs to new multi-outlet bathrooms produce slow, wasteful hot water. Rerouting and upsizing during the build fixes it permanently.
• Gas line condition: Older gas lines are assessed when appliances change, and the shift toward all-electric kitchens and heat pump hot water changes gas demand entirely on many projects.
• Missing isolation and tempering: Modern installations typically include proper isolation valves and tempering valves for safe hot water delivery to bathrooms, which older systems often lack.

Plumbing work in Victoria must be done by licensed plumbers, who typically issue a compliance certificate for work above the prescribed value. As with electrical certificates, file every one.

Every home differs, but the following ranges give Melbourne renovators a realistic planning frame. Treat them as orientation, not quotes.

The pattern worth noticing: doing these items while walls and floors are already open commonly costs a fraction of what the same work costs as a stand-alone job later, because the access cost has already been paid by the renovation.

The recurring decision on older-home projects is scope: modernise just the rooms being renovated, or use the disruption to bring the whole house forward?

• Renovation zone only: Cheaper now, and appropriate when the rest of the house was upgraded previously or budget is genuinely tight. The risk is paying for access twice when the remaining old services fail in five years.
• Whole-house services during a major renovation: When a full-home renovation already opens most walls and ceilings, completing the rewire and repipe is often only a modest increment on the electrical and plumbing packages, and it resets the clock on the entire house.
• Staged middle path: Upgrade the switchboard and any dangerous wiring immediately, complete the renovation zone fully, and rough-in provisions, such as conduit paths and capped tees, for future stages.

Our general advice: safety items are not optional and should be done regardless of scope; convenience items follow budget. A home with a modern switchboard, safe wiring and sound water delivery is worth more, insures better and lives better, even before the beautiful rooms are counted.

Because much of this scope is confirmed only after demolition, the budgeting method matters as much as the numbers.

• Pre-purchase or pre-design inspection: A licensed electrician and plumber can inspect accessible areas, the switchboard, roof space and subfloor, before contracts are priced. Many risks are visible without demolition.
• Named provisional sums: Where condition cannot be confirmed, insist the quote carries stated provisional sums for likely items, such as switchboard upgrade or galvanised pipe replacement, rather than silent exclusions.
• Contingency scaled to age: Pre-1980s homes justify contingency at the higher end, commonly 10-15% of contract value, precisely because services are the most frequent discovery category.
• Decide rules in advance: Agree with your builder before demolition which categories of discovery get fixed automatically, such as safety-critical wiring, and which come back to you for a decision. It removes pressure from mid-build conversations.

Older homes reward renovators who respect what is behind the walls. Price the era of the house honestly, use the open walls once, and the services you never see become the most durable value in the whole project.