# Background Information
# GHG Emission Factors
Emission factors are from the most recent version of the Australian Government's publication: National Greenhouse Account Factors (opens new window). The factors used in this engine are:
| Energy Source | Emission Factor |
|---|---|
| Purchased electricity (Victoria) | 0.78 kg CO2e/kWh |
| Natural (fossil) gas distributed in a pipeline | 51.53 kg CO2e/GJ |
| Liquified petroleum gas (LPG) | 60.60 kg CO2e/GJ |
| Wood | 1.2 kg CO2e/GJ |
# Occupancy Rates
Occupancy rates for different building types are built into the tool. These are used for the Energy and Water calculations, and in the Urban Ecology section for the communal spaces and food production credits.
# Dwellings
Occupant density for residential building types is derived from ABS data.
The occupancy formula is derived from the floor area. For dwellings less than 38.6 sqm, occupancy is assumed to be 1 person. Over 587.5 sqm, occupancy is assumed to be 5 people. In between these values, the following logarithmic formula is used, Occupancy = 1.471271*LN(Area)-4.375381.
# Non-residential spaces
Occupant density for non-residential building types is informed by the National Construction Code and AS1668.2 (Mechanical Ventilation of Buildings).
| Space Type | Assumed occupancy (sqm per occupant) |
|---|---|
| Office | 10 |
| Shop, retail, café | 5 |
| Laboratory or warehouse | 20 |
| Unconditioned Warehouse / factory | 50 |
| Unconditioned Showroom / Machine Shop | 20 |
| Public building | 5 |
| Other non-residential building | 20 |
# Data centres
Data halls must be treated differently to other non-res spaces in BESS.
Due to the nature of energy, water and staff time in the data hall areas, the data hall must be excluded from BESS in the Project details page, using BESS for the other areas of the development (e.g. offices). For items in BESS that rely on occupancy, for data centres, the other areas (e.g. office area) are likely to account for the majority of site needs (e.g. communal spaces, bike parking).
This will allow the potable water part of IWM, Operational Energy, IEQ, Transport and Waste categories to calculate and score based on the non-data hall areas.
The data hall shall be included in the stormwater assessment and for Urban ecology as these relate to the site as a whole.
A separate assessment for the data hall energy and water use must be included in the submission to council. This should include details of Facility Load (MW), PUE and WUE targets, recycled water and renewable energy.
Please check with the council on the preferred approach of that council.