House Extension Plans Melbourne: Complete Guide to Getting Started

A house extension is one of the most common residential building projects in Melbourne. Whether you need more living space, an extra bedroom, or a modern open-plan kitchen, extending your home is often more practical and cost-effective than moving.

This guide covers everything you need to know about getting house extension plans in Melbourne in 2026.

Types of House Extensions

Rear Extension

The most common type in Melbourne. Extends the back of the house to create a larger kitchen, living, or dining area. Often includes opening up the floor plan and connecting to outdoor spaces.

Side Extension

Uses the side setback area to add width to the home. Common on wider blocks where there is space between the house and the boundary.

Second Storey Addition

Adds a full or partial second level to a single-storey home. This is ideal when the block is too small for a ground-level extension but you need significant additional space.

Wraparound Extension

Combines rear and side extensions to maximise floor area. Often used for major renovations where the entire back of the house is redesigned.

How Much Do Extension Plans Cost?

Drafting Costs

Professional drafting for a house extension in Melbourne is quoted on scope and complexity. A simple single-storey addition sits below a double-storey or heavily constrained site.

What Affects the Price

The main factors that influence drafting costs are the size of the extension, whether it is single or double storey, the complexity of the existing structure, site conditions, and any heritage or planning overlays that apply to your property.

Construction Costs

As a rough guide, construction is priced per square metre and is the dominant cost. A modest rear extension is a substantial building budget on its own, well above the drafting fee.

Do You Need Council Approval?

Most house extensions in Melbourne require both a planning permit and a building permit.

Planning Permit

Required for most extensions that change the external appearance of the building, increase site coverage, or affect setbacks. Your local council assesses the application against the planning scheme.

Building Permit

Required for all construction work. This is assessed by a registered building surveyor and covers structural compliance, energy efficiency, and safety.

Exemptions

Some minor works may be exempt from planning permits, such as small single-storey rear extensions that meet specific criteria. However, a building permit is almost always required. Check with your council or drafter before assuming any exemption applies.

The Process from Start to Finish

Step 1: Initial Consultation

Discuss your goals, budget, and timeline. A good drafter will ask about how you use your home, what you need, and what constraints exist.

Step 2: Site Measure

An accurate measurement of your existing home forms the foundation of all drawings. This is a critical step that should never be skipped. On a recent garage and balcony extension in Glen Iris, the existing house was drawn in full before the new work was added.

Step 3: Concept Design

Your drafter prepares initial layout options showing different approaches to the extension. This is where you explore possibilities before committing to detailed drawings.

Step 4: Detailed Drawings

Once the concept is approved, detailed planning and building permit drawings are prepared. These include floor plans, elevations, sections, site plans, and shadow diagrams.

Step 5: Council Submission

Your drawings are submitted to council as part of the planning permit application. Your drafter can handle this process and respond to any requests for information.

Step 6: Building Permit

After planning approval, construction-level drawings are prepared for the building permit application.

Step 7: Construction

With all permits approved, your builder can start work.

Tips for a Successful Extension Project

Start with the End in Mind

Think about what you want to achieve before approaching a drafter. Collect images of spaces you like and make a list of your must-haves.

Budget Realistically

Allow a contingency of 10 to 15 percent above your expected construction cost. Unexpected issues are common in renovation projects.

Choose the Right Drafter

Look for experience with similar projects, knowledge of your local council, and a clear communication style. A good drafter will save you time and money throughout the process.

Do Not Skip the Site Measure

Accurate existing conditions are essential. If the base measurements are wrong, everything built on top of them will be wrong too.

How Arya Designs Can Help

We have completed hundreds of house extension projects across Melbourne. From simple rear extensions to complex double-storey additions, we deliver council-ready drawings on time with a 95% approval success rate.

Upload your plans or project brief and get a fixed quote within 24 hours.