Which room is the main living room?

The heating requirements of the healthy homes standards apply to the ‘main living room’ of a rental home. A living room can be any habitable space that can be used for general everyday living — for example, a lounge room, dining room, sitting room or family room. Living rooms can also include multi-use spaces like a studio apartment or open-plan kitchen/dining room. If you have more than one living room, use the largest living room.

What’s included in the living room?

In the tool, ‘living room’ means the whole space a living-room heater must be able to heat. You will need to include any other connected space that is always open to the living room, such as an open-plan kitchen, hallway or stairwell. Spaces are always open to each other if there is no solid barrier between them. If you can close a door or window, you don't need to include the space beyond it.

In the tool, ‘living room’ means the whole space a living-room heater must be able to heat. You will need to include any other connected space that is always open to the living room, such as an open-plan kitchen, hallway or stairwell. Spaces are always open to each other if there is no solid barrier between them. If you can close a door or window, you don't need to include the space beyond it.

How do I measure accurately?

When you measure lengths, ignore small details like skirting boards. You can also ignore small features (like pillars) that stick out from the wall, and any partial dividing walls.

Your measuring tape may show millimetres (mm), centimetres (cm) or metres (m). 1000mm = 100cm = 1m. You will need to enter your measurements in the tool in metres.

If you already have plans that show the measurements, you can use those measurements instead. If the plans use imperial measurements (feet and inches) you’ll need to convert them into metric measurements (metres).

How do I calculate the area of rectangles?

Measure the length of the room at its longest point, and the width of the room at its widest point. Length x width = area.

How do I calculate the area of other living room shapes?

Your living room may be a combination of rectangles, such as an L shape. You can break the shape down into several rectangles and add up their areas.

Or you can draw the shape on a grid and calculate the area by counting squares.

	Draw a grid or use gridded paper. Use each square to show 1m.
	Measure the room and draw the wall lengths onto the grid. In the example you can see the measurements that are not whole metres cover part of a square.
	Add up the squares the room covers. This gives you the area in square metres. If the room covers part of a square, you can calculate the exact area or count the whole square. Counting the whole square is easier but will overestimate the area.  In this example, counting the whole squares gives you an area of 10m2. The actual area is closer to 9.5m2.

If you want to keep things simple, you can even replace the complex shape of your floor with a rectangle that fully encloses it. This will overestimate the area.

How do I calculate the area of complex shapes?

Your living room may include more complex shapes, such as curves or triangles. Break down the living room into shapes you can calculate the area for, and then add the areas up.Your living room may include more complex shapes, such as curves or triangles. Break down the living room into shapes you can calculate the area for, and then add the areas up.

Use these formulas or look up the formulas for other shapes.

• Triangle: ½ x base x height = area. Measure the height of the triangle at right angles to the base. 
• Circle: 3.1416 x radius x radius = area. The radius is the distance from the centre of the circle to the edge.
• Part circle: circle area x proportion of full circle (eg ½ for a semicircle) = area

If you prefer, you can draw the shape on a grid and estimate the area by counting squares.

How do I identify internal and external walls, floors and ceilings?

External walls, floors and ceilings are more important than internal ones for trapping heat. The tool will need you to specify whether walls, floors and ceilings are internal, external or a mix.

A wall, floor or ceiling is internal if it has another conditioned space behind, below or above it. A conditioned space is an area that’s designed to be heated or cooled, like a kitchen, hallway, bathroom or other room. This applies even if it is a different home or a neighbour’s apartment.

A wall, floor or ceiling is external if it does not have a conditioned space behind, below or above it. This could include property foundations, a garage, roof space, subfloor space or the outdoors.

If a wall, floor or ceiling is a mix of internal and external, you can call it all external or you can enter the details for each part separately. If you call it all external the tool may overestimate the level of heating you actually need. This ensures the heating capacity will be enough to meet the healthy homes standards. Separating the wall, floor or ceiling into internal and external parts will give you more accurate results.

How do I measure windows, skylights and doors?

You only need to measure windows or other glazing in external walls or doors. You don’t need to measure windows or other glazing for internal walls, as the tool will treat them the same as the surrounding wall.

Measure the full size of windows and skylights, including frames. If several similar windows or panes are located together, you can treat them as one large window and give the combined size.

You don’t need to measure any doors, as we treat them the same as the surrounding wall. You need to measure any windows or other glazing in external doors.

What is an R-value?

An R-value is a measure of how well a building material traps heat. Based on the age of a home, the tool will estimate whether the walls, floors, and ceilings have insulation and how good it is (the R-value). The tool will assume that if any insulation is present that it’s in a reasonable condition.

The total R-value of a surface involves all its different layers. For example, if your wall’s layers are plasterboard, insulation and weatherboard, the R-value for each layer contributes to the total R-value. Even if your wall is not insulated, it will still have an R-value.

When should I enter my own R-value?

You can use the R-value estimated by the tool or you can enter your own R-value. For example, if your home has been upgraded with better insulation since it was built, entering the new R-value will provide a more accurate result.

The tool may estimate an R-value assuming that the property does not have insulation because of the year it was built. It’s usually easy to check under the house or in the roof space to see if insulation has been installed. All rental properties should have ceiling and underfloor insulation installed by 1 July 2019 where reasonably practicable. Some properties may not have been upgraded so the tool assumes insulation levels based on the year it was built.

How do I assess my insulation?

To assess the insulation at your property you can physically look, engage a professional to do an assessment, or check the council building file. If you're not sure of the location, type and condition of the insulation, seek advice from a professional insulation installer.

Assessing insulation

The tool will also assume that any insulation present is in a reasonable condition. If your insulation isn’t in reasonable condition you may need to upgrade it, to make sure it meets the healthy homes standards.

Healthy homes standards insulation requirements

If you’re checking insulation at a property it’s important to do this safely, particularly if there’s existing foil insulation. The installation or repair of foil insulation is banned in all residences including rental homes.

Checking insulation safely

Were there any changes to the default R-values in the tool when the changes came into effect (12 May 2022)?

The tool estimates a default R-value based on the information entered about the property.

As part of the review of the Heating Assessment Tool some of the default R-values for ceiling and underfloor insulation were reviewed and changed. You are still able to edit this R-value manually.

Changes to default R-values on 12 May 2022

Floor insulation:

Where a user actively selects ‘None of the floor’ in response to the question ‘How much of your floor has insulation that meets the required standard?’, the tool now assumes a new default floor R-value of 0.5.

This is because if the user is selecting ‘none’ then it is more likely the floor is uninsulated suspended floor than well insulated. This is because it is not uncommon for older floor insulation to rip (if foil) or fall off (if bulk insulation), making the insulation ineffective. If the subfloor is inaccessible then the landlord is exempt from upgrading the floor insulation, in which case the R0.5 for ‘None of the floor’ is appropriate.

If the floor is concrete the user should choose ‘All’.

Ceiling insulation:

Where a user actively selects ‘None of the ceiling’, in response to the question ‘How much of the ceiling has insulation that meets the required standard?’ the tool now assumes a new default ceiling R-value of 1.9.

This is because if the user is selecting ‘none’ then it is more likely the ceiling is below the healthy homes standard. If the user selects ‘none’ they are indicating this. R1.9 is still a reasonably good level of thermal performance, and there will be situations where the existing ceiling insulation has been more severely damaged over time (to a performance much lower than R1.9). However, usually such damage only occurs in accessible ceiling spaces where the landlord is obliged by the healthy homes standards to upgrade the ceiling insulation.