How Long to Build a House in Perth?

How long to build a house in Perth, realistically

Ask how long to build a house in Perth and most builders will say twelve to eighteen months from signing to handover. That is a reasonable starting point. However, a custom home usually sits at the longer end, and sometimes beyond. The reason is simple: nothing is pre-drawn.

Your plans are designed, engineered, approved and priced specifically for your block. Each of those steps takes real time before anyone turns up to dig.

Notably, the part people underestimate is not construction. It is everything that happens first. Design and approvals commonly take four to eight months. On a complex site, or where development approval is required, they take longer. Understanding that upfront makes the whole experience considerably less stressful.

Stage 1: Brief and concept

Typically four to twelve weeks.

First we work through how you want to live, what the block allows, and what your budget will realistically support. Then we develop concept plans.

Time here is well spent. Changes are cheap on paper and expensive in a slab.

Stage 2: Documentation and engineering

Usually six to sixteen weeks.

This covers working drawings, structural engineering, energy efficiency assessment, and the specification we price and build from. A contour survey and geotechnical report are also obtained at this stage.

There is very little to show for this stage and nothing to walk through. It is also where a build either gets properly resolved or quietly stores up problems for later.

Stage 3: Approvals

Anywhere from a few weeks to several months.

Once all documentation is ready, costings are finalised and the building contract is signed, the following building approvals will be processed:

BA3: Certificate of Design Compliance (CDC). A certified building surveyor will review all documentation and specifications and certify that the proposed building’s design complies with applicable Western Australian standards and the National Construction Code. It is required to be lodged for the Building Permit.

BA4: Building Permit. The official approval document issued in WA that grants legal permission to begin construction, renovation or structural alteration work.

BA20/BA20A: Encroachment and Adverse Effects / Protection, Access and Shared Structures. Required when the proposed structure crosses the neighbour’s boundary or compromises neighbouring structural stability, bearing capacity or natural site drainage. BA20A is a notice and request for consent relating to neighbour arrangements and coordination, such as protection structures beyond the boundary or removing or replacing fences for access.

Stage 4: Construction

Average 1 year from Building Permit approval, depending on the build complexity.

Site works, slab, frame, roof, lock-up, fit-out and finishing each follow in sequence. Meanwhile weather, inspections and trade availability all influence the pace.

Concrete cures at its own pace, and a trade cannot start until the one before it has finished.

What actually causes delays

Not, in most cases, the builder. In rough order of frequency:

Late decisions

The single most common cause. Unresolved selections — tiles, tapware, joinery, colours — hold up procurement. As a result, they can stall a trade sequence for weeks. Deciding early is the cheapest way to protect a program.

Approval pathways

A development approval requirement discovered late can push a program out by months. It is one of the first things worth establishing about your block.

Variations during construction

Changing your mind after work has started has a time cost as well as a money cost, particularly if it affects structure, services or anything already ordered.

Site surprises

Rock, groundwater, unexpected fill, contaminated material or what is found behind a wall in a renovation. An early survey and geotechnical report reduce — but never eliminate — this risk.

Unforeseeable events

Weather. Projects that start in winter or the rainy season are more prone to weather-related delays. As construction is done in sequence, a delay affects the slab pour, bricklaying and suspended slab installation. We can safely resume as per schedule once the roof plumbing is installed.

Tradies and supply shortages. International situations can disrupt supply chains, and construction supplies are greatly affected when those disruptions reach our shores.

We always try our best to mitigate delays, and with our great relationships with our subcontractors and suppliers, we always find solutions. Beyond this, we seek our clients’ understanding and patience regarding delays.

Planning your build

Every program is site-specific. How long to build a house in Perth depends on your block, your brief and your approval pathway, so the most useful thing we can do is look at all three together and give you a realistic timeline rather than a generic one.

See how our building process works stage by stage, read about what a custom home costs to build in Perth, or browse projects we have completed.