Interior painting in Australia

A room is three surfaces, and each takes a different paint

Painting the inside of a house feels like one job, but step into any room and there are really three surfaces in front of you, and they don't behave the same way. The walls are the big flat areas your eye lands on. The ceiling is overhead, usually flat white, and it's painted first. And the doors, skirting and window trim are the third surface, the bits that get touched and knocked, so they're finished differently again.

Why does that split matter? Match the paint to each surface and the room looks right and wears well. Treat the whole room as one job with one tin and you get a ceiling that shows roller marks, trim that scuffs, or walls in the wrong sheen. So the way to read this guide is surface by surface, with prep as the thread that runs under all three.

Each surface gets its own short section below so you know what's involved before you go deep on yours. Let's start with the surface that takes the most paint: the walls.

Walls: the big flat surface, where most of the paint goes

Walls are the surface most people mean when they say 'painting a room', and they're the bulk of an interior job. They usually take a low-sheen or matt acrylic: a water-based paint that goes on fast, is low-odour, and hides small flaws in the plaster rather than showing them off.1Dulux TradeView source On a sound, prepared wall, two proper topcoats over primer give even colour and a finish that stands up to wear, which beats one heavy single pass every time.4DuluxView source

The wall questions worth getting right are how many coats and whether you need an undercoat, and those depend on the state of the wall, the colour change, and whether the surface is bare. Those are the details to settle for your own room before you start.

Ceilings: painted first, flat white, and a job of their own

The ceiling is its own surface, and it's usually painted before the walls so any drips or roller spray land on surfaces you haven't finished yet.4DuluxView source 5TaubmansView source Ceilings are almost always a dedicated flat white: a dead-flat finish hides imperfections in a surface that catches a lot of side light, and white keeps the room feeling bright and tall. It's a separate step in the job, not an afterthought tacked onto the walls.

The ceiling questions are how many coats it needs and the sequence that keeps the room clean: cut in, then roll, with the ceiling done before the walls. Those are the points to nail down if the ceiling is your sticking point.

Doors and trim: an enamel finish, and the water-vs-oil call in miniature

Doors, skirting and window trim are the third surface, and they get handled and knocked, so they usually take an enamel: a harder, wipeable finish that survives fingers and furniture better than a wall paint.1Dulux TradeView source That's where the old water-based-versus-oil-based question shows up. A modern water-based enamel dries fast and keeps its colour; an old oil-based enamel gives a higher, smoother gloss but tends to yellow out of sunlight and gets harder and more brittle as it ages.

For most homes that points to a water-based enamel on the trim, in a sheen that suits how much the doors get used.6Haymes PaintView source Which exact sheen, and how much sanding the old surface needs first, are the calls to make for your own doors before the enamel goes on.

What an interior job costs comes down to prep, coats, access and condition

Interior painting is quoted the way you actually live in the house: in rooms and bedrooms, not in square metres. A painter thinks in 'three bedrooms plus the hallway', and that's the language to plan in. Once you know the surfaces, the price makes more sense, because four things set it and the paint tin is the smallest of them.

The biggest driver is prep: the filling, patching, sanding and cleaning that gets the surface sound before any colour goes on. Prep is heavier on older homes with worn paint and cracked walls, and it's labour, so it moves the number most. The other three stack on top. The number and quality of coats matters, access and ceiling height matter (stairwells, high ceilings and scaffold all add time), and so does the state of the surface. A clean recoat is a smaller job than stripping back worn old layers. That's usually why two interior quotes for the same-size home look different: it's prep and condition, not a dearer brand of paint.

Your real number depends on your rooms and their state, so the most useful thing is a range built from your own home. Use the live estimate below, then see the full breakdown by area on the cost guide.

Prep and lead: fix the surface first, and check older homes before you sand

The part of an interior job that comes first in practice is dealing with what's wrong with the surface. Filling cracks, patching holes, sanding back peeling paint and treating damp at its source is a real, priced job on its own. It's the least glamorous step and the most important, because a fresh coat over a bad surface just inherits the problem. A coating only performs on a sound surface, and that's exactly the condition makers put on their own guarantees.2DuluxView source Skip the prep and you pay to redo the same wall sooner.

There's a safety step that comes before any of that on an older home. Houses built before 1970 often used high-lead paint, and paint made before 1965 could hold as much as 50 per cent lead, with the limit only falling to 1% in 1965, 0.25% in 1992 and 0.1% in 1997.3DCCEEWView source Lead is a health hazard, and you can't tell by looking. So if your home is from that era, have the old paint checked by a licensed professional before anyone sands or scrapes it. That's a job for someone working to the regulator's guidance, not a DIY task. And where damp or mould keeps coming back through the paint, that usually points to a cause behind the wall that a relevant trade should price and fix first.