What actually drives the cost of an interior painting job

Homeowners usually expect an interior painting quote to be driven by square footage. It is a reasonable assumption and it is mostly wrong. Two bedrooms of identical size can be a full day apart in labour, and the difference is never the amount of paint.

Here is what a contractor is actually pricing.

How much repair the surfaces need

This is the single biggest variable and it is invisible in a photo taken from the doorway. Walls with settled cracks, recurring nail pops, previous patches that were skimmed unevenly, or plaster that has moved all need genuine repair time before anything is primed.

A room that needs two hours of patching and a room that needs a day of it get quoted very differently, and any contractor who does not look closely enough to tell the difference is either going to hit you with a change order or skip the repair.

The amount and complexity of the trim

Trim is slow. It is brushwork, it needs its own masking, and it dries at a different rate to the walls, which means it occupies its own place in the schedule rather than being done alongside.

A room with plain modern baseboard and one door is not comparable to a room with crown, chair rail, deep window returns and three panelled doors — even at identical square footage.

Ceiling height

Everything above standard height means staging, slower cutting-in, and more time per square foot. A stairwell or a two-storey entry is a different job from a bedroom, not a bigger one.

How big the colour change is

Two finish coats is standard. Deep colours, strong accent walls and large jumps from dark to light frequently need three to cover evenly. A good contractor will tell you after priming whether that is the case, rather than after you have been billed for two coats and are looking at a patchy wall.

Whether you are living in the house

Occupied work costs more, and it should. Rooms have to be sequenced so you keep a kitchen, a bathroom and a route between them. Furniture is moved and covered rather than gone. Dust has to be contained properly, because uncontained sanding puts fine dust through the HVAC returns into every room in the house.

What is not driving the price

• The paint itself. Materials are a small fraction of an interior quote — the labour is the quote.
• The wall area alone, for all the reasons above.
• How fast someone says they can do it. A quote that is cheap and quick is usually cheap and quick because the prep is not in it.

How to get a quote that means something

Send photos. Close-ups of any wall damage, a shot of the trim detail, and a wide shot of each room tells a contractor more than a room count does, and it means the number you get back is close to the number you pay.