Guides

Written from the regulator's own material, read rather than recalled, and cited so you can check us.

These are the questions buyers, sellers and owners actually ask us, answered from the Building and Energy industry bulletins and the Australian Standards rather than from general advice written for another state. Each guide cites what it draws on, so you can check the source yourself. Where a rule turns on a date — and several of the most important do — the guide gives you the date and tells you which side of it your house sits on.

They fall into three groups. Compliance at sale and transfer: smoke alarms, RCDs, and the obligations that catch sellers out. Defects and how they are read: ceilings that fail, roof tie-downs, chemical delignification, and wet areas. Termites: the management standards and the inspection zone most Perth houses build over. Start anywhere — each one links to the ones next to it.

Guide

Selling a house in WA? Your battery smoke alarms probably aren't legal

Western Australia requires compliant mains-powered smoke alarms before a home changes hands. What that means, when a bat…

Read more →
Guide

Do your smoke alarms have to be interconnected in WA?

Interconnection is required for newer WA homes and not for older ones. The cut-off is 1 May 2015, and it is the building…

Read more →
Guide

Short-stay smoke alarm rules changed

WA amended its smoke alarm regulations for dwellings offered as short-term rental accommodation. What changed, who it ap…

Read more →
Guide

Perth ceilings that fall down on their own

Building and Energy investigated unexplained plasterboard ceiling collapses in WA homes. What they found, which years ar…

Read more →
Guide

The 25mm gap that decides whether your termite barrier works

AS 3660 governs termite management in Australian buildings. What it covers, what it deliberately does not, and the inspe…

Read more →
Guide

Metal roofs act like a wing. Tie-downs are what stop them leaving.

Building and Energy inspected 123 sheet metal clad timber framed roofs in WA and found a low level of compliance.…

Read more →
Guide

Wet areas are the most commonly failed part of a new build

Waterproofing under AS 3740, who is licensed to do it in WA, the four places wet areas leak, and why Perth winters are w…

Read more →
Guide

A pool is the most common reason a Perth settlement gets held up

WA pool barrier rules: the 300mm definition, AS 1926.1, the November 2001 threshold, gate and non-climbable-zone traps, …

Read more →
Guide

The little grille in the brickwork is doing a job

Subfloor ventilation in Perth's timber-floored and suspended-slab homes: why the void has to breathe, the 150mm rule, ho…

Read more →
Guide

The name on the sign may not be the business building your house

WA builder registration, how to verify it, and the licence-lending risk Building and Energy warned about — why the name …

Read more →
Guide

Your builder has to build the house that was approved

Work must match the approved plans. Building and Energy's Industry Bulletin 154, where builds depart from their approval…

Read more →
Guide

How many houses is your builder running at once?

A registered builder must manage and supervise the work under their registration. Industry Bulletin 153, why thin superv…

Read more →
Guide

Building in a bushfire-prone area: what a BAL rating costs you

Bushfire Attack Level assessment under AS 3959: the bands from BAL-LOW to BAL-FZ, when it is required, what each level c…

Read more →
Guide

Buying a house backing onto bush: what to know first

Is the block bushfire-prone, what that means for an existing house, what triggers a BAL assessment, and the ember-vulner…

Read more →
Guide

Damage: one of six defect types in AS 4349.1

The AS 4349.1 defect type where the building fabric has ruptured or broken, why cracking is the headline case, and when …

Read more →
Guide

Distortion: the defect type most likely to be structural

The AS 4349.1 defect type where an element has moved or twisted out of position — bowing, racking, leaning — usually the…

Read more →
Guide

Water penetration: the root of the defect family tree

The AS 4349.1 defect type for moisture entering where it shouldn't — rising damp, salt damp, leaks and poor drainage — a…

Read more →
Guide

Material deterioration: the defect Perth's coast accelerates

The AS 4349.1 defect type covering rust, rot, corrosion, decay and chemical breakdown — including delignification…

Read more →
Guide

Operational: mostly minor, occasionally a warning

The AS 4349.1 defect type for components that don't function — windows, doors, drainage — mostly maintenance, but someti…

Read more →
Guide

Installation: missing tie-downs, missing ant caps, off-plan work

The AS 4349.1 defect type for work installed badly, wrongly, or missing — the standard names missing tie-downs and missi…

Read more →
Guide

Reactive-clay footing movement

Footing movement on Perth's reactive clay: why it happens, AS 2870 site classes, how it shows up, and when it meets the …

Read more →
Guide

Fixing footing movement: underpinning, trades and standards

Rectifying footing movement in Perth: stabilising moisture first, underpinning methods, the structural engineer and regi…

Read more →
Guide

Concrete spalling: when the steel inside rusts

Concrete spalling (concrete cancer) in coastal Perth: how chloride and carbonation rust the reinforcement, why balconies…

Read more →
Guide

Fixing concrete spalling: trades, methods and AS 3600

Rectifying concrete spalling in Perth: why patching fails, proper corrosion-arrest repair, the structural engineer and c…

Read more →
Guide

Structural timber decay: a moisture problem in a timber costume

Fungal decay in structural timber in Perth: the 20% moisture threshold, where bearers and framing rot, AS 1684.2 durabil…

Read more →
Guide

Fixing timber decay: stop the water, then the wood

Rectifying structural timber decay in Perth: fixing the moisture source first, replacing to correct durability, the engi…

Read more →
Guide

Combustible cladding: is it on the building you're buying into?

Combustible cladding on WA apartments: what the BCA requires, the state-wide audit that referred 52 buildings for buildi…

Read more →
Guide

Wind classification: a structural defect hiding on a form

Wind classification under AS 4055 and AS/NZS 1170.2: how getting it wrong under-builds a house, why tie-down requirement…

Read more →
Guide

Home indemnity insurance: your protection if the builder fails

Home indemnity insurance in WA: what it covers, the $20,000 threshold, when the builder must provide the certificate…

Read more →
Guide

Hot water scald control: 50 degrees, and why it's stored hotter

WA requires heated water delivered at max 50C to showers, baths and basins. The 1 May 2024 expansion, the Legionella bal…

Read more →
Guide

Floor wastes: the fall that decides whether a bathroom leaks

Wet-area floor wastes and grading under AS 3740 and the NCC: the minimum falls, why membrane errors around the waste cau…

Read more →
Guide

Balcony waterproofing: the membrane over your living room

External balcony and podium waterproofing under AS 4654.1 and AS 4654.2 and the NCC: why it differs from internal wet ar…

Read more →
Guide

Ventilation, condensation and mould: the moisture a house can't get rid of

Ventilation and condensation under the NCC: why houses get damp inside, interstitial condensation in cavities, the exhau…

Read more →
Guide

7-star NatHERS and Whole-of-Home: the new energy rule for WA homes

NatHERS energy ratings for new WA homes: the 6-to-7-star lift from 1 May 2025, the new Whole-of-Home requirement, NCC 20…

Read more →
Guide

Lead-free plumbing: what's changing in your drinking water fittings

The national lead-free plumbing rule: Clause A5G4 of the PCA limiting copper alloy fittings to 0.25% lead, the 2026-2028…

Read more →
Guide

Building permits in WA: BA1, BA2, and when you need one

WA building permits: the certified (BA1) and uncertified (BA2) routes, the 10 vs 25 business-day timeframes, Schedule 4 …

Read more →
Guide

Notice of Completion: the BA7 that closes out a build

The WA Notice of Completion (form BA7) under section 33 of the Building Act: the seven-day rule, the $10,000 penalty, th…

Read more →
Guide

Building levies: the value of work, and the 2026 threshold change

WA building levies: the Building Services Levy and the CTF levy, how the value of work is estimated under Schedule 1…

Read more →
Guide

Buying strata in WA: the 2020 reforms and your information rights

WA's 2020 strata reforms: the compulsory pre-contract disclosure that lets you evaluate a scheme's finances, SAT as the …

Read more →
Guide

Sewer connection and drainage: where your responsibility runs to

WA sewer connection rules: drainage plumbing runs to the main sewer junction (IB 163), the 1 July 2024 PLB certification…

Read more →
Guide

Owner-builder rules: what you take on when you're the builder

WA owner-builder rules: Building Services Board approval, the owner-builder course, the six-year rule, and the seven-yea…

Read more →
Guide

Drainage plumbing diagram: the map of your underground drains

The WA drainage plumbing diagram: what it records, why you need it before digging or landscaping, how it fits the 2024 c…

Read more →
Guide

Roof penetration flashing: where sealant fails and formed flashing works

Flashing roof penetrations on metal roofs in Perth: the AS 1562.1 clause 4.8 drainage rule, why over-reliance on sealant…

Read more →
Guide

Roof batten connections: the critical fixing that holds your roof on

The batten-to-rafter connection under AS 1684.2 Section 9 and Table 9.25: why it's critical against wind uplift, the IB …

Read more →
Guide

Fire separation of roofed outdoor areas: the rule your patio may trigger

WA's fire-separation rule for roofed outdoor areas: WA H3D7 and Part 9.6 of the ABCB Housing Provisions, why alfrescos a…

Read more →
Guide

Coastal corrosion: why fasteners fail before the roof they hold

Fastener corrosion on Perth's coast: AS 3566.2 corrosion classes (Class 3 vs Class 4), the same-service-life rule, galva…

Read more →
Guide

Retaining walls: WA's 500mm rule catches more than owners expect

WA retaining wall rules: the 500mm permit threshold measured from the low side, when a structural engineer and AS 4678 a…

Read more →
Guide

What a building inspection covers under AS 4349.1

What a WA pre-purchase building inspection covers under AS 4349.1: visual and non-invasive, readily accessible areas, th…

Read more →
Guide

Termite barriers for new builds under AS 3660.1

Termite management for new WA homes under AS 3660.1: physical vs chemical barriers, why timing before the slab pour is c…

Read more →
Guide

Dilapidation reports: your baseline before the works next door

Dilapidation reports in Perth: the pre-construction condition record that protects you when neighbouring demolition or e…

Read more →

Why we write these

Most building-defect advice online was written for framed houses on reactive clay in Sydney or Melbourne. Perth is mostly double brick on sand, its ground changes as you move inland, and its worst roof defect barely exists on the east coast. A guide that does not know that is worse than no guide, because it sounds right. Everything here is written for this city, by a registered building contractor, and cited so you are not taking our word for it.