How Much Does a Kitchen Extension Cost in Australia? Full Cost Breakdown

A bigger, brighter kitchen with space for entertaining is one of the most common renovation goals for Australian homeowners. But once inspiration turns into planning, reality quickly sets in. The true kitchen extension cost isn’t just about cabinetry and appliances—it’s about constructing a brand-new part of your home, with all the approvals, structural work, and professional expertise that entails.

Across Australia, kitchen extensions typically range from $80,000 for a small, straightforward build to $250,000+ for larger or architecturally complex projects. The variation comes down to size, structure, site conditions, location, and finish level. Understanding how these factors interact is the key to budgeting with confidence rather than guesswork.

One of the first decisions homeowners face is whether to renovate within the existing footprint or extend outward. This choice has a major impact on cost.

A renovation works with what’s already there. A kitchen extension creates entirely new space—new foundations, new structure, and new external building elements. That difference explains the significant jump in price.

Kitchen Extension Cost Compared to Renovation Scope

To put it simply:

• Kitchen renovation: cabinetry, benchtops, appliances, finishes

• Kitchen extension: all renovation elements plus slab or subfloor, framing, roofing, insulation, external walls, windows, and compliance upgrades

In real terms, a quality kitchen renovation might cost $35,000–$70,000, while even a modest extension that adds usable floor area will usually start around $80,000–$100,000.

Builders like RJG Group often guide clients through this decision early, helping them determine whether better layout planning can solve space issues—or whether only an extension will truly meet their needs.

Kitchen Extension Cost Per Square Metre in Australia Explained

Many homeowners hear a “per square metre” rate and assume it represents the full project cost. In reality, it’s only part of the picture.

In the current Australian market, kitchen extensions typically fall within these realistic 2025 build ranges:

• $3,000–$3,800 per sqm – basic, straightforward extension

• $3,800–$4,800 per sqm – mid-range finishes, some complexity

• $5,000+ per sqm – high-end design, structural challenges, premium finishes

Kitchen Extension Cost Per Square Metre: What It Usually Covers

In most cases, the per-sqm rate covers construction to lock-up stage only, meaning:

• Foundations or subfloor

• Framing

• External walls and roof

• Basic windows and external doors

What it doesn’t include:

• Kitchen cabinetry and appliances

• Plumbing and electrical fit-off

• Flooring, lighting, splashbacks, painting

This is why homeowners are sometimes shocked when a “$90,000 extension” becomes a $160,000–$200,000 completed kitchen once the fit-out is added. Treat per-sqm pricing as a sizing guide—not a final quote.

Kitchen Extension Cost Breakdown: Before, During, and After the Build

A realistic budget looks at the entire lifecycle of the project—not just construction.

Design and Approvals

Before a builder lifts a hammer, several professional steps are required:

• Drafting or architectural drawings

• Structural engineering

• Council or private certifier approval

In most Australian states, these pre-construction costs range from $6,000 to $15,000, depending on complexity. Council approval timeframes can also add months to your schedule, which should be factored into planning.

Experienced builders aligned with industry standards, including those referenced by the master builders association, ensure designs are compliant from day one—reducing approval delays and redesign costs.

Construction and Services

Once approved, the core build begins. Major cost drivers include:

• Foundations: slab on ground vs raised subfloor (soil conditions matter)

• Structure: simple rectangles cost less than complex shapes

• Services: relocating plumbing, gas, and electrical infrastructure

An open-plan kitchen with an island sink, for example, requires new drainage runs under the slab—adding both labour and materials. Electrical upgrades may also require switchboard modifications in older homes.

This is where experienced project coordination from teams like RJG Group becomes critical to avoid costly sequencing mistakes.

Kitchen Fit-Out

The fit-out is where personal choices drive the final number.

Realistic current estimates (AUD):

• Cabinetry:

  • Flat-pack or modular: $6,000–$10,000

  • Custom joinery: $20,000–$35,000

• Benchtops:

  • Laminate: $200–$350 per linear metre

  • Engineered stone: $700–$1,100 per linear metre

  • Natural stone: $1,200–$1,800+ per linear metre

• Appliances:

  • Standard package: $5,000–$8,000

  • Premium integrated appliances: $15,000–$25,000+

These figures reflect current supplier pricing and labour rates across major Australian cities.

Even the best plans need breathing room. A 10–20% contingency is essential for issues like:

• Unexpected asbestos

• Unrecorded plumbing or wiring

• Weather delays

There are also lifestyle costs: temporary kitchens, takeaway meals, or short-term accommodation during critical stages. Landscaping and external finishes are often excluded from build contracts and should be budgeted separately.

Is a Kitchen Extension Worth the Cost?

Once the numbers are clear, the question becomes less about price and more about value. A kitchen extension can significantly improve resale appeal, but its biggest return is often lifestyle—space to cook, gather, and live without compromise.

With the right planning, transparent pricing, and an experienced builder, what first feels overwhelming becomes a controlled, well-managed investment. RJG Group regularly helps homeowners navigate this process with clarity, realistic budgeting, and end-to-end delivery.

Ready to Take the Next Step?

Understanding your kitchen extension cost puts you in control. The next move isn’t committing—it’s starting the right conversation with professionals who understand both construction realities and household priorities.

Contact Us at RJG Group, reach out today to discuss your kitchen extension goals and receive guidance grounded in real-world experience, transparent costs, and proven building expertise.