PERTHBuying 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-vulnerable features a buyer should check
You have found a house you like, backing onto bush, and the view is half the reason you want it. Before you fall for it entirely, there is a question worth answering: is this block in a designated bushfire-prone area, and if so, what does that mean for a house that is already built?
Check the map first
The Department of Fire and Emergency Services publishes a Map of Bush Fire Prone Areas for Western Australia. If the block is shown in pink, it is designated, and a set of consequences follows that a buyer should understand before making an offer rather than after.
Being in a bushfire-prone area does not make a property a bad buy. Large parts of the most desirable semi-rural and bush-fringe Perth is designated. It does mean the property comes with obligations and characteristics that a buyer inland of the bush line does not face, and those are worth pricing in.
What it means for an existing house
The construction requirements of AS 3959 apply to new building work — a new dwelling, or significant additions and renovations. An existing house built before its area was designated, or built to an earlier standard, is not automatically non-compliant, and there is no general obligation to upgrade it to current bushfire construction standards simply because you are buying it.
But two things matter to you as the buyer. First, if you plan to add to or significantly renovate the house, that work will trigger a BAL assessment and the corresponding construction requirements, which is a cost to factor into any plan you have for the place. Second, the features that improve a house's chances in a bushfire — ember-proofed roof and eaves, screened vents, sealed gaps, non-combustible materials near the ground — are worth knowing the state of, because they are what stands between the building and an ember attack regardless of what the regulations require.
What to look at on the ground
The vegetation and its distance from the house, because that is what drives the exposure. The state of the roof and its penetrations, since roofs are where embers most often get in. Eaves, vents and weep holes, and whether anything screens them. Gutters full of leaf litter, which is fuel sitting on the building. Decks and underfloor areas where embers can lodge. And whether there is a water supply that would be useful in a defence.
None is a dealbreaker alone. Together they tell you whether the house has been maintained with its setting in mind or in spite of it.
How we help
A pre-purchase inspection on a bushfire-fringe property covers the building against AS 4349.1 as it would anywhere, and we will also tell you the visible state of the ember-vulnerable elements — roof, eaves, vents, gaps — so you know what you are taking on. We are not accredited BAL assessors, and where a formal assessment is needed, for a renovation plan or a lender, that is a separate specialist engagement, which we will say plainly rather than imply we cover.
Buying into the bush is a fair choice made with open eyes. The point of the inspection is to make sure your eyes are open.
What a bushfire-prone designation actually changes
Discovering that a property is in a designated bushfire-prone area is not a reason to walk away, but it is a reason to understand what the designation carries with it, because it changes the rules that apply to building and can change what you are able to do with the property. The designation is a mapped classification, and where a property falls within it, building and significant renovation work can trigger a bushfire attack level assessment, a BAL assessment, which grades the level of bushfire risk the building faces and drives construction requirements accordingly. A higher BAL rating means more stringent, and more expensive, construction standards for anything you build, from the materials of the external walls and windows to the detailing that stops embers getting in.
For someone buying an existing house in one of these areas, the immediate practical questions are two. First, what does the designation mean for the house as it stands, which for an existing dwelling is often little in the day-to-day but becomes significant the moment you want to extend, renovate substantially, or rebuild. Second, what does it mean for the risk you are taking on as an owner, which is a real and physical question about the house's exposure and defensibility, separate from the regulatory one. Both are worth understanding before you commit, and neither is a reason for panic; large numbers of desirable Perth properties, particularly in the leafier hills and semi-rural fringes, carry the designation.
Reading the risk on the ground
Beyond the map and the regulations, there is the physical reality of the individual property, and this is where an informed look at the house and its setting earns its place. The things that drive real bushfire risk to a specific house are its proximity to bushland and other vegetation, the slope of the land, which affects how fire behaves as it approaches, the density and type of vegetation around the building, and the construction and condition of the house itself, particularly the details that determine whether wind-blown embers can find their way in. Embers, rather than a direct flame front, are what ignite most houses in a bushfire, and the vulnerable points are the gaps: unscreened vents, gaps in the roof, accumulated debris in gutters, timber decks and the spaces under them.
A house well-sited and well-detailed for its setting is a very different proposition from one with bushland pressing against a timber deck, gutters full of leaves, and unscreened subfloor vents, even if the two sit on the same street with the same BAL designation. Looking at these things, the setting, the vegetation, the ember-entry points, the general condition, gives a buyer a far more grounded sense of the actual risk than the map alone, and points at the practical measures, screening, clearing, maintenance, that reduce it.
Where an inspection fits
A standard building inspection is not a bushfire assessment, and it is important not to confuse the two: a formal BAL assessment is specialist work carried out for building and planning purposes, and it is separate from an inspection of the building's condition. But an inspection of a house in a bushfire-prone area can, as part of assessing the building, note the condition-related factors that bear on ember risk, the state of the gutters, the presence or absence of vent screening, the condition of eaves and roof junctions, decking and subfloor exposure, because these are things that both affect the building generally and happen to matter for bushfire. For a buyer in one of these areas, that grounded look at the house, combined with an understanding of what the bushfire-prone designation means for future work, is the practical knowledge that turns an intimidating label into a manageable set of considerations.
A designation to manage, not to fear
The reasonable way to hold all of this is that a bushfire-prone designation is something to understand and manage, not something to fear or to walk away from automatically. Many of Perth's most sought-after settings, the hills, the leafy fringes, the semi-rural pockets, carry the designation precisely because they are close to the bush that makes them attractive. What matters is going in informed: knowing what the designation means for any future building work, understanding the physical risk of the specific property and its setting, and knowing which practical measures, vegetation management, ember-proofing the vulnerable entry points, keeping gutters and surrounds clear, actually reduce that risk. A buyer who understands these things is in a position to make a sensible decision and to manage the property responsibly. A buyer who either ignores the designation or panics at it is not. The knowledge is what turns an intimidating label into a set of manageable considerations.
Common questions
How do I know if a property is bushfire-prone?
Check the WA Map of Bush Fire Prone Areas published by DFES. If the block is shown in pink, it is designated, and bushfire planning and construction consequences follow.
Do I have to upgrade an existing house to bushfire standards?
Not automatically. AS 3959 applies to new work — a new dwelling or significant additions and renovations. An existing compliant house is not required to be upgraded simply on sale, but any future renovation will trigger the requirements.
What should I check on a bush-fringe house?
The vegetation and its distance, the roof and its penetrations, eaves and vents, gutters clear of litter, decks and underfloor areas, and whether there is a useful water supply.
This comes up on every pre-purchase building inspection and building investigation & diagnostics we carry out.
Read next: the little grille in the brickwork is doing a job and building in a bushfire-prone area: what a BAL rating costs you.
Sources
Read rather than recalled. Summarised here; the documents themselves are Crown copyright and are linked rather than reproduced.