# IEQ
Best practice design for Indoor Environment Quality (IEQ) means that building occupants can enjoy a comfortable space with good air quality, adequate daylight and ventilation. Australians spend on average 90 percent of their time indoors, therefore the quality of the indoor environment is vital to our health and wellbeing. Building design and material choices impact on indoor environment quality and are considered during the early design stages, making IEQ a core category of BESS. Design for IEQ will also deliver other benefits such as reduced energy use for heating, cooling and lighting.
In the IEQ category, BESS includes actions regarding daylight, ventilation, solar access and thermal comfort. Information required and points available are dependent on type and scale of the project. IEQ considerations that are not captured in BESS but are also important include:
- Acoustic privacy
- External views
- Air quality
- Toxicity of materials, e.g. Low volatile organic compound (VOC) paints, sealants and adhesives
Our Indoor Environment Quality Fact Sheet (opens new window) can help you with design strategies for your development.
# IEQ profile
Profiling questions apply for multi unit residential developments (apartments) - here you can specify which daylight metric and pathway you wish to use.
What metric do you want to use for daylight to apartments?
Select either Daylight Factor (DF) or Spatial Daylight Autonomy (DA). This selection applies to all apartments - using a combination of DF and DA for different dwellings is not permitted.
The credits linked to each metric are as follows:
- Daylight Factor metric: IEQ 1.1 Daylight Access – Living areas and IEQ 1.2 Daylight – Bedrooms
- Spatial Daylight Autonomy metric: IEQ 1.5 Daylight Access – Main Living areas and IEQ 1.6 Daylight Access – Secondary Habitable rooms
# Daylight factor
Where daylight factor is the chosen metric, a further selection is required, between:
- Deemed to satisfy
- Use the built in calculation tools
- Provide own calculations
# Deemed to Satisfy
Under the DtS method there is no partial compliance.
Satisfy ALL of the criteria below to achieve credits IEQ1.1 and IEQ1.2:
- Are all living areas and bedrooms less than 8m deep (5m if south facing)?
- Do all living areas and bedrooms have a floor-to-ceiling height of at least 2.7m?
- Does all glazing to living areas achieve at least 60% Visible Light Transmittance (VLT)?
- Do all living areas have an external facing window (not into a courtyard, light well or other major obstruction)?
- Does the building(s) comply with all of the requirements of the building separation tables?
# Table 1. Building separation to adjacent properties
| Minimum building separation (measured from property boundary) | ||
|---|---|---|
| Building Height | Living/Main balcony outlook to boundary line | Bedroom outlook to boundary line |
| Up to 4 storeys / 12 metres | 6 metres | 3 metres |
| 5-8 storeys / up to 25 metres | 9 metres | 4.5 metres |
| 9+ storeys / over 25 metres | 12 metres | 6 metres |
Notes:
Building separation is not required to the side or rear boundary where no outlook is proposed provided it does not affect the reasonable development opportunity of the adjoining site.
Zero building separation applies on sites where a continuous street wall is encouraged under the relevant place based planning controls.
Where existing dwellings have not incorporated access to daylight to habitable rooms on their own site in accordance with the building separation standards, the building separation standards will only apply to new development to the extent necessary to achieve comparable contribution (from a minimum of 1 metre and a maximum of 3 metres) of daylight into the habitable rooms of the proposed dwellings.
The building separation requirements commence at the first level of residential use
# Table 2. Building separation to a lane
| Minimum building separation | ||
|---|---|---|
| Building Height | Living/Main balcony outlook | Bedroom outlook |
| 2 storeys / 9 metres | 0 metres (from boundary) | 0 metres (from boundary) |
| 3-8 storeys / up to 25 metres | 6 metres (from lane centre line) | 3 metres (from lane centre line) |
| 9+ storeys / over 25 metres | 9 metres (from lane centre line) | 6 metres (from lane centre line) |
Notes:
- The building separation requirements commence at the first level of residential use
# Table 3. Building separation for buildings within sites
| Minimum building separation | |||||
|---|---|---|---|---|---|
| Building Height | Living / Main balcony outlook to Living / Main balcony outlook | [Bedroom](/tool-notes/bess9/glossary.html#bedroom) outlook to [bedroom](/tool-notes/bess9/glossary.html#bedroom) outlook | Living / Main balcony outlook to [bedroom](/tool-notes/bess9/glossary.html#bedroom) outlook | Living / Main balcony outlook to no outlook | [Bedroom](/tool-notes/bess9/glossary.html#bedroom) outlook to no outlook |
| Up to 4 storeys / 12 metres | 12 metres | 6 metres | 9 metres | 6 metres | 3 metres |
| 5-8 storeys / up to 25 metres | 18 metres | 9 metres | 13.5 metres | 9 metres | 4.5 metres |
| 9+ storeys / over 25 metres | 24 metres | 12 metres | 18 metres | 12 metres | 6 metres |
Notes:
- The building separation requirements commence at the first level of residential use
# Table 4. Lightwell Minimum areas and dimensions (considered a building separation table)
| Building Height | Minimum lightwell area and dimension |
| Up to 4 storeys / 12 metres | 9m2 (minimum width 3m) |
| 5-8 storeys / up to 25 metres | 29m2 (minimum width 4.5m) |
| 9+ storeys / over 25 metres | 51m2 (minimum width 6m) |
Notes:
The light court minimum areas and dimensions may need to be varied for buildings containing multiple levels of non-residential uses
The minimum area and dimension must be achieved for the entire depth of the light well.
The minimum width should be read as the minimum dimension in plan view. This could be either the width or length depending on how these are applied.
# Built in calculation tools
Where daylight factor is the chosen metric, and 'Use the built-in calculation tools' has been selected.
Group all habitable rooms (living areas and bedrooms) into the following categories:
- Living areas that meet the Deemed-to-Satisfy criteria can be entered as 'Auto-Pass'
- Bedrooms that meet the Deemed-to-Satisfy criteria can be entered as 'Auto-Pass'
- Living areas of varying orientation
- Bedrooms of varying orientation
For each grouping that is not 'Auto Pass', provide an average of the following:
- Room Floor Area
- Vertical Angle
- Horizontal Angle
- Window Area
- Glass Type
# Provide own calculations
Where daylight factor is the chosen metric, and 'Provide our own calculations' has been selected.
Provide daylight modelling using third party software according to the daylight modelling requirements.
# Spatial Daylight Autonomy profile
Where spatial daylight autonomy is the chosen metric, provide daylight modelling using third party software. Modelling should be conducted to all main living areas and secondary habitable rooms of varying orientation and configuration. See the daylight modelling parameters in this section for more information.
- Adequate daylight = Minimum 200 lux for at least half of winter (1 June to 31 August) daylit hours.
- Visual acuity daylight = Minimum 50 lux for at least three quarters of winter (1 June to 31 August) daylit hours.
# Main living areas
You will need to know which main living areas fall within the ‘single metric bounds’. Treat these as one group, and the main living areas that fall outside these bounds as another group.
# Within the single-metric bounds
Main living areas within the single metric bounds are those meeting all of the following criteria:
- Room depth from glazing not greater than 9.0m
- Balcony overhang outside glazing not greater than 3.6m deep
- VLT not less than 0.35 (35%)
- Building height not greater than 36m
- At least 90% of the room is within direct line of sight of glazing
For these, where adequate daylight to at least half of the floor area of the room is achieved, then visual acuity daylight to at least 90% of the floor area of the room is deemed to be met (and does not need to be tested separately).
# Outside the single metric bounds
For main living areas outside the ‘single metric bounds’, then both adequate daylight and visual acuity daylight must be modelled.
If there are no main living areas outside the single-metric bounds then this question is Not Applicable.
Excepting where 'Not Applicable' is selected, you must answer Yes to both of these questions to achieve points in IEQ1.5 - Main living areas
- Does every main living area that meets the single-metric bounds achieve adequate daylight to at least 50% of the floor area?
- Does every main living area outside the single-metric bounds achieve: - adequate daylight to at least 50% of the floor area AND - visual acuity daylight to at least 90% of the floor area?
Answering Yes to these questions achieves a 66% score in IEQ1.5.
Additional points are awarded in IEQ1.5 where the answer to the next spatial daylight autonomy question is more than 50%, that is:
- For main living areas, what is the lowest % floor area of adequate daylight of any individual area?
# Secondary habitable rooms
For secondary habitable rooms:
- the test is adequate daylight to 50% of the room floor area only (no visual acuity test)
- only 80% of rooms need to meet the test in order to achieve points in IEQ1.6 (compared with 100% of main living areas for IEQ1.5)
- however, all rooms must meet a lower test: adequate daylight to 25% of the room floor area
In order to answer the spatial daylight autonomy profile for secondary habitable rooms:
- use modelling to test how many rooms meet adequate daylight to 50% of the room floor area
- calculate the percentage of rooms that meet this criteria = (number of secondary habitable rooms meeting the criteria / total number of secondary habitable rooms in the development)
- verify that all rooms meet adequate daylight to 25% of the room floor area
# Daylight modelling requirements
To meet the requirements for multi-residential developments, daylight modelling should be conducted to all habitable rooms of varying orientation and configuration
To meet the requirements for non-residential developments, daylight modelling should be conducted to all occupiable areas other than ancillary areas
A report of the modelling should be provided as evidence for the related credits with the BESS report and include the following:
- Modelling software including version and release date
- Location and co-ordinates
- Time of year and time of day
- Sky conditions
- Orientation
- Visual Light Transmission (VLT) for all glazing modelled
- Reflectance surface properties
- For open plan living areas, the extent to be modelled is to include the lounge, dining, kitchen and any circulation space not separated by a wall or opening/door.
- Tabulated results of spaces assessed, including the room name/number, floor area (sqm) of the room, floor area (sqm) above minimum required daylight metric and percentage of the floor area meeting the daylight metric criteria.
- 3D views capturing all elevations to indicate that all shading devices and adjoining buildings have been modelled.
- Model adjacent buildings per their likely developed form based on current zoning (mirrored). Confirm this with the relevant council if potential future development on adjoining lots is unclear.
- Daylight contour plots (Heatmaps) superimposed over the architectural plans for clarity and to ensure the areas have been modelled correctly. These are to graphically show the extent of daylight penetration to the apartment which will support the stated figures.
The daylight modelling is a check of built form related outcomes. As such it should not include outdoor or indoor furniture, vegetation, indoor artwork or floor rugs and must be modelled using set modelling parameters as follows:
# Table 5. Daylight modelling parameters - Grid parameters and material properties
| Daylight Modelling Parameter | Setting / Value |
| Grid plane | Horizontal |
| Grid height level | 0.85m (above finished floor level) |
| Grid resolution | 0.5m x 0.5m (maximum) |
| Grid offset (from internal walls) | 0.00m |
| Reflectance of floors (interior floor and floor of private open space) | 0.30 |
| Reflectance of interior walls | 0.70 |
| Reflectance of ceiling | 0.80 |
| Reflectance of external surface (except ground and lightwells walls) | 0.30 (approximates an average brick wall) |
| Reflectance of external lightwell walls | 0.40 (approximates off-form concrete) |
| Reflectance of external ground surface | 0.10 (approximates asphalt) |
| Diffuse reflectance of translucent glazing | 0.07 |
| Diffuse transmittance of translucent glazing | = VLT (Visible Light Transmittance) |
| Specular transmittance of translucent glazing | 0.00 |
# Table 6. Daylight modelling parameters - Daylight Autonomy occupancy schedule
| Occupancy Schedule | Setting / Value |
| Time of year | June 1 to August 31 |
| Number of days | 7 day week |
| Time period | 9:00 to 17:00 inclusive per day |
# Table 7. Daylight modelling parameters - Daylight Autonomy weather files
| Weather File | Source |
| Representative Typical Meteorological Year (TMY) EnergyPlus weather (EPW) file for the location | https://climate.onebuilding.org/WMO_Region_5_Southwest_Pacific/AUS_Australia/index.html |
| Example: Melbourne's International Airport Typical Meteorological Year (TMY) EnergyPlus weather (EPW) file for 2004 - 2018 | https://climate.onebuilding.org/WMO_Region_5_Southwest_Pacific/AUS_Australia/VIC_Victoria/AUS_VIC_Melbourne.Intl.AP.948660_TMYx.2004-2018.zip |