In a British house, carpet is the default for bedrooms, stairs and often the living room, and hard floors are the exception. In a modern Brisbane house the balance tips the other way, and polished concrete is one of the most common choices for anyone with a slab to work with. This piece sets out how the two compare in Queensland’s heat and humidity, and what to ask before you choose.

Start with what the house sits on

Not every Queensland home can take polished concrete. The traditional Queenslander is a timber house raised on stumps, with timber floorboards, and there is no slab to polish. Most houses built in recent decades, though, are slab-on-ground: the floor is a concrete slab poured directly on the prepared site. That slab can be ground and polished as the finished floor, either during the build or later when old flooring is pulled up.

Polishing an existing slab is more of a lottery than polishing a new one. Old glue, tile adhesive, patches, cracks and plumbing repairs all show through. A contractor can usually tell you after a test grind whether the result will look deliberate or patchy, and some owners decide on a coloured or covered finish once they see what lies beneath.

How the climate changes the argument

Brisbane summers are long, hot and humid. A concrete floor in a shaded, well-ventilated room tends to feel cool underfoot and absorbs heat slowly, which helps keep indoor temperatures steadier. That is the thermal mass effect, and it works best when sun is kept off the floor in summer by eaves, awnings or blinds. A slab that bakes in afternoon sun through a west-facing window will store heat and release it into the evening, which is the opposite of what you want.

Carpet behaves differently. It insulates the floor from the room, so you lose the cooling effect of the slab. In persistent humidity it can also hold moisture, which makes it more prone to musty smells and mould, and it gives dust mites somewhere comfortable to live. Allergy sufferers often notice the difference after moving to hard floors.

Winter is where carpet earns its keep. Brisbane winters are mild by British standards, but houses here are often poorly insulated, and a concrete floor on a cool June morning can feel cold. Rugs in living areas and bedrooms are the usual compromise.

Side by side

Grind levels and sealers

The look of polished concrete is set mainly by how deep the floor is ground. A light grind leaves the cement surface largely intact, with few stones showing. A medium grind exposes fine aggregate in a speckled finish, often called salt and pepper. A deeper grind reveals the larger stones for a full-exposure look. Deeper grinding generally costs more and removes more of the surface, and on an existing slab the stone that appears may be uneven in colour and spread.

The finish matters as much as the grind. A mechanically polished floor is refined with progressively finer abrasives and densified so the concrete itself carries the shine. A grind-and-seal floor relies on a topical coating, such as a urethane or epoxy, to provide the gloss. Topical sealers can look excellent but may scratch, wear in traffic paths and need recoating. If you would like to see how local specialists explain the options, reading up on polished concrete in Brisbane from a firm that does this work every day will give you the vocabulary to compare quotes properly.

Slip resistance and safety

A high-gloss floor can be slippery, especially when wet, and Brisbane’s storm season means wet feet at the back door. Slip resistance in Australia is assessed against a standard that gives surfaces a rating, and some finishes can be treated to improve grip. Ask what rating a finish is likely to achieve in kitchens, laundries and near outdoor entries, and consider a less glossy finish or mats in those spots. For households with young children or elderly relatives, the hardness of the floor on a fall is worth weighing too.

A sensible plan for many families is polished concrete in living areas, kitchens and hallways, with carpet or large rugs in bedrooms. It gives the cooling benefit where you spend summer afternoons and a little British softness where you get out of bed.

Questions readers ask

Can I polish the slab under my existing carpet?

Often yes, if the house is slab-on-ground, but the result depends on what is underneath. A test grind in a small area will show the condition before you commit.

Does polished concrete crack?

Fine cracks are common in slabs and polishing will reveal them rather than cause them. Many owners accept them as part of the character, though they can be filled.

Is carpet a bad idea in Queensland?

Not at all, particularly in bedrooms. It simply needs good ventilation and regular cleaning to stay fresh in humid months.

Across Cronulla, Miranda, Gymea and Sutherland itself, a large share of the older housing stock is single-storey fibro cottages built in the 1950s and 1960s. This piece explains what that means for a British buyer weighing up renovation against a full knockdown-rebuild, and why asbestos sits at the centre of the decision.

What a fibro cottage actually is

“Fibro” is the Australian name for fibre cement sheeting. Before the mid-1980s, most of it contained asbestos, and it was used for external cladding, eaves linings, wet-area walls and sometimes internal ceilings. Post-war Sydney was built quickly and cheaply, and the Shire was one of the places where young families bought a quarter-acre block with a modest fibro house on it.

These houses have very little in common with a British brick semi. They usually sit on brick or timber piers with a timber subfloor, have a timber frame, and were often extended in stages over the decades with whatever material was to hand. In good condition, bonded fibro is considered low risk while left alone; the trouble starts when you want to cut, drill, sand or remove it, which is exactly what renovation involves.

The land underneath is usually the real asset. Blocks in the Shire are often generous by Sydney standards, and many buyers are effectively paying for the site and treating the house as temporary.

Asbestos: testing first, then licensed removal

Do not assume a fibro house is entirely asbestos, and do not assume a later extension is free of it. A licensed asbestos assessor or occupational hygienist can take samples and produce a register or survey showing where the material is and what type it is. A pre-purchase building inspection may flag suspected asbestos, but that is not the same as a proper survey.

In New South Wales, removal is regulated by SafeWork NSW. Friable asbestos (the crumbly kind, sometimes found in old pipe lagging or vinyl backing) must be removed by a Class A licensed removalist. Bonded material such as fibro sheeting requires a Class A or Class B licence once you go beyond a small quantity, and the rules for homeowners doing tiny amounts themselves are strict and easy to get wrong. In practice, for a whole house, a licensed contractor is the only sensible route, and a clearance certificate should follow the removal.

Disposal goes only to facilities licensed to take asbestos waste. Dumping is treated very seriously, and councils and the state environment regulator do prosecute.

Renovate or knock down?

The calculation is different from the UK, where you rarely knock down a sound house. Here, a fibro cottage that needs new cladding, new wet areas, rewiring, restumping and insulation can cost a substantial fraction of a new build while still leaving you with an old layout and low ceilings. That is why knockdown-rebuild is so common in the Shire.

Renovation can still make sense when the frame and subfloor are sound, when you like the scale of the house, or when a heritage or character listing limits what you can do. Some owners strip and replace the external fibro, reclad in weatherboard or fibre cement, and keep the bones. Others add a second storey, though an old timber frame on piers is not always able to take one without major structural work.

A knockdown-rebuild gives you a modern energy-efficient design, current bushfire or coastal construction standards if they apply, and a known cost. It also brings demolition, a period of renting elsewhere, and the full weight of approvals.

The approval pathway, step by step

Most knockdown-rebuild projects in NSW follow roughly this order, though details depend on the block and the council’s controls:

1. Check the planning controls on the NSW Planning Portal and Sutherland Shire Council’s local plan, including any bushfire, flood, coastal, heritage or tree overlays.
2. Get the asbestos survey and a site survey done early, as both feed into design and demolition planning.
3. Decide on the pathway: a complying development certificate from a private certifier where the project fits the state codes, or a development application to council where it does not.
4. Arrange disconnection of electricity, gas, water and sewer with the relevant utilities before demolition begins.
5. Engage a licensed demolition contractor, who will coordinate asbestos removal, site fencing, dust control and waste.
6. Only then does the builder start on site, under the approved plans and with inspections at the required stages.

Demolition and construction approvals are often lodged together. Trees can catch people out: the Shire has a significant tree canopy, and removing a large tree may need separate permission even when the house is coming down. Because the work combines hazardous materials with tight suburban sites, it is worth reading a local firm’s guidance on demolition in the Sutherland Shire before you commit to a design, as they will know how the council and certifiers in the area tend to handle these jobs.

Practical points for British buyers

Build the asbestos survey into your due diligence before exchange if you can, since removal costs vary with the amount and type found. Ask for any previous approvals and certificates from the vendor, particularly for extensions. Budget for temporary accommodation, as a full rebuild in Sydney commonly runs well past a year from purchase to moving in.

Finally, verify the licences of everyone involved. Builders, demolition contractors and asbestos removalists are licensed separately in NSW, and those details can be checked with the state regulators.

Questions readers ask

Is it safe to live in a fibro house before we rebuild?

Bonded fibro in good, undisturbed condition is generally regarded as low risk. The danger comes from breaking, drilling, sanding or water-blasting it, so leave it alone until it is removed properly.

Can I remove a few sheets of fibro myself?

The NSW rules allow very limited homeowner work under strict conditions, but they are easy to breach and disposal is tightly controlled. For anything more than a minor repair, use a licensed removalist.

Does every knockdown-rebuild need a development application?

No. Many straightforward projects qualify for a complying development certificate from a private certifier. Overlays such as heritage, flood or bushfire can push a project into the full council application process, so check the controls for your block.

Perth regularly sees summer days above 40°C, and a growing number of its homes have polished concrete floors. The two are connected, and not always in the way new arrivals expect. This piece looks at how a polished slab behaves through a Perth summer and winter, and what it means for British families used to carpeted, suspended timber floors.

How Perth houses are built

A large share of Perth houses, particularly from the 1970s onwards, are double brick built on a concrete slab laid directly on the ground. That is different from most of the eastern states, where brick veneer on a timber frame is more common, and very different from a British semi with a suspended timber floor over a void.

In many of these homes the slab has traditionally been covered with carpet, tiles or floating timber. Polishing removes that layer and makes the slab itself the finished floor. The concrete is ground back with progressively finer abrasives, sometimes exposing the stone in the mix, then densified and either sealed or honed to a sheen. On older slabs the result depends heavily on the condition and the original mix, so expect some variation in colour and texture.

Because so much depends on the slab you already have, it is sensible to read a local specialist’s guidance before committing. The information at polishedconcretefloorsperth.au covers the grinding, finish and sealing options for Perth slabs and is a reasonable place to start before asking for an assessment.

Thermal mass and the 40-degree day

Concrete is dense. It takes a long time to warm up and a long time to cool down, a quality known as thermal mass. On a hot day, a shaded slab in contact with the ground absorbs heat from the room air and releases it slowly, which helps keep indoor temperatures steadier. Walk barefoot onto a polished floor in a darkened room in January and it feels pleasantly cool.

That benefit depends on the slab staying in shade. Thermal mass works in both directions. A polished floor sitting in direct afternoon sun through a west-facing window will soak up heat for hours and give it back into the evening, which is exactly when you want the house to cool down. The common approaches are external blinds, eaves of a decent depth, and keeping the curtains drawn on the west side through the hottest part of the day.

Perth also has the advantage of the afternoon sea breeze, locally called the Fremantle Doctor, which arrives on many summer afternoons. Opening the house up once it comes through, and again overnight when the outside air drops below the inside temperature, lets the slab shed heat. Close up again in the morning before the heat builds. Double brick walls and a polished slab together make that rhythm quite effective.

The other side: winter

Perth winters are mild by British standards, but they are wet and nights can drop to single figures. Many Perth houses have little or no insulation under the slab, so the floor stays at something close to ground temperature. In July a bare polished floor can feel cold underfoot, and British families often find the house chillier than they expected.

Rugs solve most of this. They sit over the areas where people actually stand and sit, add some sound absorption, and can be rolled away when summer returns. Slippers do the rest. Hydronic underfloor heating can be laid in new slabs, but retrofitting it into an existing polished floor is generally impractical, so it belongs to a new build or a full renovation conversation.

Winter sun is the opposite of summer sun. Letting low northern sun fall across the floor during the day allows the slab to collect some warmth and release it into the evening, which is another reason to think about shading in seasonal terms rather than closing everything all year.

Dust, allergies and day-to-day care

For families who arrive with a child sensitive to house dust mites, a hard floor is often a relief after wall-to-wall carpet. Dust stays on the surface where a dry mop or vacuum picks it up, rather than settling deep into pile. Perth’s dry, dusty summers mean floors need regular sweeping, but the job is quick.

Care is fairly simple. Use a pH-neutral cleaner, avoid harsh acids and bleach that can etch the surface, and put felt pads on furniture legs. Grit carried in on shoes acts like sandpaper over time, so a mat at each door does more than any polish. Sealed floors may need resealing after some years, depending on the system used and the traffic.

There are drawbacks to weigh. Hard floors carry sound, so a house with a lot of polished concrete can feel echoey until rugs and soft furnishings go in. Dropped glasses break. A slab with old cracks will show them, and new hairline cracks may appear as the concrete continues to move slightly. Most owners treat these as part of the character, but it is better to know in advance.

Questions readers ask

Can any existing slab be polished?

Most can be ground and sealed, but the look depends on the concrete underneath, and old glue, paint or patching can leave marks. A contractor will usually want to inspect the slab, often after lifting a small section of the existing covering.

Will polished concrete make the house cooler on its own?

Only if the slab is kept out of direct summer sun and the house is ventilated when the outside air is cooler. Without shading, it can store heat rather than help.

Is polished concrete slippery when wet?

A high-gloss finish can be slippery, particularly near outside doors and in bathrooms. Honed finishes and anti-slip treatments are available for those areas.

A large share of Brisbane’s older inner-west suburbs sit on hillsides, and a block in Ashgrove, The Gap or Bardon will often fall several metres from front boundary to back fence. This piece explains what a site cut is, why it shapes the cost and design of almost any new build or extension on a slope, and what to sort out before anyone turns up with an excavator.

Why this is new territory for most British buyers

Most UK housing sits on reasonably level plots, and where it doesn’t, the house was built long ago and the slope is somebody else’s historic problem. Extensions tend to go out the back on strip foundations.

In Brisbane, the hillside block is normal rather than exceptional. Traditional timber “Queenslander” houses were raised on stumps precisely so they could sit over uneven ground without much digging. Modern slab-on-ground houses, pools, granny flats (a self-contained second dwelling, roughly the equivalent of a garden annexe) and level lawns all need flat ground, and on a slope that ground has to be made.

Cut, fill and what holds it all up

A site cut means excavating into the high side of the block to create a level platform. Fill is the opposite: building up the low side with compacted material. Many jobs mix the two, known as cut-and-fill, to reduce the soil trucked off site.

Either way, the change in level has to be held back. That means retaining walls, which on a steep Brisbane block can be the single largest line item in the groundworks. Common types include:

• Timber sleeper walls – cheaper and quick, but with a limited lifespan and generally suited to low heights.
• Concrete sleeper walls with steel posts – a popular middle ground for residential gardens.
• Besser block (concrete masonry) walls – reinforced and core-filled, used for taller or structural walls.
• Interlocking segmental block walls – a gravity system often used for landscaping tiers.

In Queensland, retaining walls above a modest height, or those carrying a load such as a driveway or a building close to the top, generally need engineering design and building approval. The exact triggers depend on height, surcharge and distance from boundaries and structures, so confirm them with a building certifier or Brisbane City Council before you price anything.

Brisbane ground: clay one metre, rock the next

The ground under the western suburbs is notoriously variable. Many blocks have reactive clay near the surface that swells when wet and shrinks in the dry, which affects slab design and site classification. Beneath that, it is common to hit weathered rock that ranges from crumbly to very hard within the same excavation.

Rock changes the equipment and the price: a small excavator that sails through clay may need a rock breaker once it reaches harder material, which is why contractors often price rock separately. A geotechnical report, which most builders and engineers will want anyway for footing design, gives you a better idea of what lies underneath before you commit.

Stormwater and overlays

Cutting into a hillside changes where water goes. Rain that used to run across the surface now meets the back of a retaining wall, so walls need drainage behind them: an ag drain (a perforated slotted pipe in gravel) at the base, free-draining backfill and an outlet to a legal point of discharge. Brisbane’s summer storms deliver heavy rain quickly, and poor drainage soon shows in saturated walls, wet slabs or water heading towards a neighbour.

Brisbane City Council also maps a number of overlays that can apply to a block, including landslide, flood, bushfire and vegetation protection. A steep block in The Gap or Bardon may well sit under a landslide overlay, which can mean extra reports and assessment before earthworks are approved. Vegetation protection can restrict which trees you can remove to make room. Check the council’s online mapping for your address early, because an overlay can shape the whole design.

Getting from bare slope to a level pad

Whether the end goal is a house slab, a granny flat or a pool, the sequence tends to look similar:

1. Survey the block. A contour and detail survey shows levels, boundaries, services and trees.
2. Get a geotechnical report. This classifies the site and tells the engineer what the soil and rock are likely to do.
3. Design the cut and the walls together. The level of the pad, the height of each wall and the drainage path should be resolved on paper, not on the day.
4. Obtain approvals. Depending on overlays and wall heights, that may involve council assessment, a building certifier, or both.
5. Check underground services. Before You Dig Australia provides plans of buried services.
6. Excavate, retain and drain. On steep sites, walls are often built in stages as the cut progresses so the face is not left unsupported.

Because the soil, rock, overlay and drainage questions are all specific to the street and even to the block, it pays to talk early to an experienced earthworks contractor in Brisbane who can look at the site, read the survey and tell you where the costs are likely to sit. Spoil removal, rock, walls, engineering and machine access all add up, so treat any price heard before a site visit as indicative only, and ask how rock and extra spoil will be charged.

Questions readers ask

Is it cheaper to build a raised house than to cut the block?

Sometimes. A suspended floor on piers or stumps avoids much of the excavation and retaining, though the building itself may cost more, so it is worth asking a designer to compare both approaches for your particular slope.

Can I put a pool on a sloping block?

Yes, but it usually needs either a cut into the hill or an engineered pool shell partly out of the ground, plus retaining and drainage. Pool fencing rules apply regardless of the design.

Who is responsible if my retaining wall affects the neighbour?

Responsibility for boundary walls can be complicated and depends on who changed the ground levels and on Queensland law, so get advice before building close to a boundary and keep your approvals and engineering documents.

A July morning in Melbourne or Canberra can feel colder indoors than a January morning in Manchester, even though the outside temperature is often higher. The reason is the building, not the weather. This piece explains why so many Australian homes struggle in winter and what can realistically be done about it.

Houses built for summer

For most of the twentieth century, Australian houses were designed to get rid of heat rather than keep it in. Raised timber floors with open subfloors, high ceilings, wall vents and single-glazed windows all help a house breathe in summer. In winter, the same features let warmth escape almost as fast as you can produce it.

Insulation requirements came late. National energy efficiency rules for new homes only arrived in the early 2000s, and they have been tightened several times since. The current requirements sit in the National Construction Code, maintained by the Australian Building Codes Board, but they apply to new building work. A house from the 1960s or 1980s may have little or no wall insulation, a thin layer in the roof, and nothing under the floor.

Winters are milder, not mild

British arrivals often assume that Australian winters are an afterthought. In the tropical north they largely are. Further south they are not. Canberra and the tablelands get regular frosts, Hobart and much of Victoria have long, damp cool seasons, and even Sydney’s western suburbs can drop close to freezing overnight. The Bureau of Meteorology’s climate information lets you look up typical winter minimums for a suburb before you buy or rent, which is worth doing if you are choosing between areas.

The catch is that winters are just mild enough that many homes were never given proper heating. Central heating with radiators in every room, standard in British housing, is uncommon. Instead, you find a single gas heater in the living room, an old ducted system, or a reverse-cycle air conditioner (an electric heat pump that heats as well as cools) mounted high on one wall.

How it compares with a typical British home

The differences are easiest to see side by side. These are generalisations about older housing stock, and plenty of individual homes on both sides break the pattern.

Aluminium window frames deserve a mention on their own. Aluminium conducts heat very well, so the frame itself becomes a cold bridge, and condensation can run down the inside on winter mornings. That moisture is a frequent cause of mould around windows.

What makes the biggest difference

For owners, the order of priority is broadly the same as in Britain: stop the draughts, insulate the roof, deal with the windows, then improve the heating. Sealing gaps around doors, skirting boards and old exhaust fans is cheap and often surprisingly effective. Topping up ceiling insulation is usually the next best value. Underfloor insulation is worth considering on raised timber floors where there is crawl space to fit it.

Windows are more expensive to tackle. Heavy, well-fitted curtains with pelmets help a great deal, and secondary glazing or replacement double glazing are options where budgets allow. On the heating side, a modern reverse-cycle unit is generally much cheaper to run than plug-in electric heaters, and in many states government programmes have offered rebates for efficient heating. Check what is currently available in your state.

Some of the same changes also help in summer. Insulation and shading keep heat out as well as in, which is covered in more detail in our guide to heat-proofing an Australian home.

For renters

Tenants have fewer options, but not none. Some states, including Victoria, have introduced minimum standards for rental properties that cover things such as a fixed heater in the main living area. The rules vary by state and are changing, so check with your state’s tenancy authority. Otherwise, draught snakes, thick curtains, rugs and a portable oil-filled heater go a long way, and it is worth asking about heating when you inspect.

Questions readers ask

Are new Australian houses warmer?

Generally, yes. New homes must meet energy efficiency standards under the National Construction Code, which have been raised over time, though build quality and orientation still vary.

Why are my windows wet on winter mornings?

Warm, moist indoor air condenses on cold single glass and aluminium frames. Better ventilation, extraction in bathrooms and kitchens, and improved glazing all reduce it.

Is gas heating being phased out?

Some states, notably Victoria and the ACT, have moved to limit gas connections in new homes. Existing gas heaters can usually still be used, but check your state’s current policy before replacing one.

Whether a deck, shed or carport needs approval in Australia depends on three things: which state the property is in, the size and position of the structure, and any overlays that apply to the land. The rough British equivalent is permitted development, but the Australian system splits the question between planning and building rules, and each state draws the lines differently. This guide sets out how to work out where your project sits before anyone starts digging.

Planning and building are separate questions

In England, people often think of “planning permission” as the single hurdle, with building regulations as a later technical check. Australia has a similar division, but it shows up more clearly for small structures.

Planning approval concerns whether the structure is acceptable on that land: its use, its position, its appearance and effects on neighbours, heritage, trees and flooding. Building approval concerns whether it is safely designed and built: footings, framing, wind loads, fire separation and so on. A shed might be fine on planning grounds but still need a building permit, or the reverse.

Who issues these approvals also varies. Councils handle planning in every state, but building approvals may come from the council or from a private building surveyor or certifier, depending on the state.

How the main states approach it

In New South Wales, many small structures can be built as “exempt development” with no approval at all, provided they meet every listed standard for size, height, setback from boundaries and other conditions. If a project falls just outside those standards, it may qualify as “complying development”, which can be approved quickly by a council or registered certifier. Anything else needs a development application. The NSW Department of Planning explains exempt and complying development and links to the detailed codes, which are worth reading carefully because a single unmet condition removes the exemption.

In Victoria, the main question is usually whether a building permit is needed, issued by a registered building surveyor. Small outbuildings and low decks can be exempt within set limits, but carports and larger sheds generally are not. A separate planning permit can be needed where overlays apply. Consumer Affairs Victoria’s housing and building pages cover homeowners’ rights and obligations when engaging builders for this kind of work.

Queensland, Western Australia, South Australia, Tasmania and the territories each have their own exemption lists and processes. The common thread is that exemptions are conditional, and the conditions change over time, so always confirm current rules with your council or a building surveyor.

What tends to trigger approval

Without quoting thresholds that differ by state and change with amendments, the factors that most often push a small project into needing approval are:

• Floor area above the exempt limit for that type of structure.
• Height, including how high a deck sits above the ground.
• Closeness to a side or rear boundary, or to the street.
• Attachment to the house, which brings in fire separation and structural questions.
• Heritage, flood, bushfire or vegetation overlays on the land.
• Easements and sewer lines under the proposed site.
• Location in a strata or community title scheme, which adds a separate layer of consent.

Carports catch many people out because they are often attached to the house and sit forward of the building line, two conditions that frequently remove exemptions. Raised decks are another, especially on sloping blocks where one corner can sit much higher than the other.

A practical way to check

1. Find out the zoning and any overlays from your council’s online mapping or a planning certificate.
2. Read the state’s exemption rules for the specific structure, not a general summary.
3. Measure the proposed size, height and boundary distances against each condition.
4. If anything is borderline, ask the council’s duty planner or a building surveyor before ordering materials.
5. Check easements and services on the title, and get underground services located before digging.
6. If approval is needed, decide who will apply: you, the builder, or a private certifier where the state allows it.
7. Keep every approval document and final inspection certificate with the property records.

Whoever builds it should hold the right licence or registration for the value and type of work in your state; our guide to checking a builder’s or tradie’s licence covers how to look them up.

Unapproved structures when buying

If you are buying a house with an existing deck, shed or carport, ask whether it was approved. Unapproved work can lead to council orders, insurance questions and problems when you sell. In some states a certificate can be obtained after the fact if the structure meets the rules; in others, it may have to be altered or removed. A conveyancer and a building inspector can help identify the risk before settlement.

Questions readers ask

Does a garden shed from a hardware store need approval?

Often not, if it is small, low and set back from boundaries. Each state has conditions, and overlays can still apply.

Can my neighbour object to an exempt structure?

Exempt development has no formal approval for them to object to. If it breaches the conditions, though, they can complain to council.

Who is responsible if the builder skipped approval?

Responsibility generally sits with the owner, though you may have recourse against the builder. Confirm approvals before work starts.

The cheapest way to keep an Australian house cool is to stop the sun reaching it in the first place. Air conditioning has its place, but shade, roof treatment and moving air do much of the work for free once they are in. This article sets out what matters most, roughly in the order a British owner tends to discover it.

Stop the sun before it reaches the glass

In a British house, sunshine through a window is welcome for most of the year. In much of Australia, a large unshaded west-facing window can turn a room into an oven by mid-afternoon. Glass lets solar heat in readily and is poor at letting it back out, so the most effective shading sits outside the window, not inside it.

Internal blinds and curtains help a little, but by the time the sun hits them the heat is already inside. External options work far better:

• Eaves and awnings over north-facing windows, which block high summer sun while letting lower winter sun in.
• Adjustable external blinds or shutters on east and west windows, where the sun is low and hard to block with a fixed overhang.
• Pergolas with deciduous vines, which shade in summer and drop their leaves for winter.
• Trees and shrubs on the west side, planted with enough clearance from foundations and gutters.
• Window films or performance glazing where external shading is not practical, such as in apartments.

Remember that in the southern hemisphere the sun sits to the north. British habits of favouring a south-facing garden need reversing here: a north-facing living area with well-sized eaves is the classic recipe for comfort all year round.

Eaves: why older houses got it right

Plenty of older Australian homes have generous eaves, wide verandahs and deep porches for exactly these reasons. Some newer project homes have very narrow eaves or none at all, often to fit as much floor area as possible on a smaller block. Those houses tend to rely more heavily on air conditioning.

The right eave width depends on latitude, window height and orientation, so there is no single figure. Designers work it out from sun angles, and the energy efficiency provisions of the National Construction Code, published by the Australian Building Codes Board, take shading into account when a new home is rated. If you are extending or renovating, ask your designer to show how the shading will perform in midsummer and midwinter.

The roof is the biggest heat source

On a hot day, a roof absorbs a great deal of solar energy and passes it down into the ceiling space, which can become far hotter than the outside air. Without good insulation that heat radiates into the rooms below well into the evening.

Three changes make the most difference. Bulk insulation in the ceiling slows heat flow in both directions and is usually the best-value upgrade. Reflective foil sarking under the roofing, typically installed when a roof is built or replaced, reflects radiant heat. A lighter-coloured roof absorbs less heat than a dark one; many councils and some state planning rules now favour lighter roof colours in new developments for this reason. Whirlybirds and powered roof vents can also help clear hot air from the roof space, though their effect is more modest.

Moving air through the house

Australian houses were traditionally designed for cross-ventilation: windows on opposite sides, high ceilings and doors that can be left open to let a breeze pass right through. Whether that works depends on where you live. In coastal cities, an afternoon sea breeze can be used well. Inland, where nights can stay hot during a heatwave, the approach is often to close up the house during the day and open it at night when the air outside is cooler.

Ceiling fans are cheap to run and make a room feel several degrees cooler by moving air across the skin. Most Australian homes have them, and if yours does not, installing them requires a licensed electrician. Fly screens on windows and doors let you ventilate without inviting in mosquitoes and flies.

Know your climate

The balance between shading, ventilation and insulation shifts across the country. Humid tropical areas favour lightweight, airy houses with maximum shade. Hot, dry inland areas can benefit from thermal mass, such as a slab floor or masonry walls, combined with night cooling. Temperate cities need a house that copes with both a heatwave and a cold winter. The Bureau of Meteorology’s climate data gives average temperatures, humidity and heatwave patterns by location, which is useful before planning any renovation.

Many of the same measures also keep the warmth in during the colder months, which is covered in our piece on why Australian houses feel cold in winter.

Questions readers ask

Is air conditioning a sign a house is poorly designed?

Not necessarily, as most homes in hot regions benefit from it during heatwaves. A well-shaded, insulated house simply needs it less often and runs it more cheaply.

Can I add eaves to an existing house?

Sometimes, depending on the roof structure, but it can be costly. Awnings, pergolas and external blinds are usually simpler ways to add shade.

Do I need approval for an awning or pergola?

It depends on size, height, position and your state and council rules. Check with your local council before building.