Thinking of adding more space to your home, maybe an extra bedroom, a bigger living area, or finally setting up that home office? A house extension is a great way to get what you need without the stress or cost of moving.
But before you start ringing up builders or picking out tiles, there is one thing you absolutely need first: council-approved extension plans. And not just any plans ,they need to be drawn by someone who knows WA building codes, local council rules, and the R-Codes inside and out.
That is where we come in. At Perth Drafting, we help homeowners across Perth get fast, affordable, and council-ready plans for all types of extensions, from simple rear additions to full double-storey upgrades.
What Are House Extension Plans?
Extension plans are detailed technical drawings that show exactly how you plan to change your existing home. Councils, builders, and engineers rely on these plans to assess and approve your project.
You will usually need extension plans for:
- Development approval (DA) or building permits
- Structural engineering
- Getting accurate quotes from builders
- Legal compliance and site inspections
A full set of plans typically includes:
- Existing and proposed floor plans
- Site plan showing boundaries and setbacks
- Elevations (front, side, rear views)
- Roof layout
- Construction notes
- R-Code compliance details
In short, these plans are your green light for getting the project off the ground.
What Can You Extend in a Perth Home?
There are heaps of ways to extend a home, depending on your block size, layout, and goals. Some popular options in Perth include:
- Rear extensions for open-plan living, kitchens, or dining
- Second storey additions for extra bedrooms or parents’ retreats
- Side extensions to add an office, bathroom, or laundry
- Alfresco and outdoor areas for entertaining
- Granny flats or ancillary dwellings for rental or extended family
- Master suite upgrades with walk-in robes and ensuite bathrooms
We regularly work on sloping blocks, narrow lots, older character homes, and newer suburbs with stricter planning codes.
Do You Need Council Approval?
Yes, in most cases. Almost all home extensions in WA require a Building Permit, and many also need a Development Application (DA), especially if you are:
- Extending close to boundaries
- Changing the roof height or adding a second storey
- Reducing setbacks
- Creating overshadowing or privacy impacts
- Changing the external appearance of your home
At Perth Drafting, we prepare everything you need for council submission and deal with your specific local government, whether you are in Stirling, Joondalup, Wanneroo, or anywhere in between.
How Much Do Extension Plans Cost?
Our drafting prices usually range from $1,200 to $3,500+, depending on the size and complexity of the project.
That includes all required drawings, R-Code checks, and support with your council application. There are no hidden fees, and we will always give you a clear quote up front.
Pro tip: Hiring a draftsman is often 50 to 70 percent cheaper than engaging an architect for the same residential extension.
Why Use a Draftsperson Instead of an Architect?
For most residential extensions, a licensed draftsman is more than capable and much more affordable.
Here is why many Perth homeowners choose us:
- We understand local council rules and WA building codes
- We produce clear, builder-friendly plans
- We offer faster turnaround and flexible pricing
- We collaborate closely with engineers and builders
- We focus on buildable designs, not just fancy ones
Unless your project is highly specialised or architectural, you are likely better off with drafting.
Common Mistakes to Avoid
We have seen it all over the years. Here are a few common mistakes to avoid:
- Skipping planning rules — Always check your zoning and R-Code requirements first.
- Poor design — A bad layout can ruin the flow of your home.
- Not matching the existing home — Materials, roof pitch, and finishes matter.
- Underestimating cost or time — Council approvals, engineering, and site work all take time.
- No site measure — Always get a proper site measure before designing.
We can help you avoid these mistakes from the start.
Frequently Asked Questions (FAQ
1. How long does it take to draft and approve house extension plans?
Most plans are completed within 1–2 weeks, with council approvals taking an additional 2–6 weeks, depending on the project and area.
2. Can you design my extension to match the existing house?
Yes, we’ll draft your extension so it blends seamlessly with your existing home, including matching rooflines, materials, and finishes where needed.
3. Do I need a structural engineer for a house extension?
Yes. Once your plans are drafted, they’re sent to a structural engineer for certification before building approval. We can connect you with trusted local engineers
