Northern Beaches Council area
Age specific propensities (birth and death)
This relates to the modelling of births and deaths. At each year of age, there is a certain statistical likelihood of a person dying or giving birth. These age specific propensity rates are applied to the base and forecast population for each year of the forecast period.
Ageing in place
This refers to an existing resident population ageing in their current location, as distinct from other impacts on future population such as births, deaths and in and out migration.
Average annual percentage change
A calculation of the average change in total population for each individual year.
Average household size
The average number of persons resident in each occupied private dwelling. Calculated as the number of persons in occupied private dwellings divided by the number of occupied private dwellings. This excludes persons living in non-private dwellings, such as prisons, military bases, nursing homes etc.
'Bottom up' forecast
Population forecast based on assumptions made at the local area level. Local drivers of change such as land stocks and local area migration form the basis.
Broadhectare Land or Sites
Broadhectare land refers to undeveloped land zoned for residential development on the fringe of the established metropolitan area. These areas are generally used for rural purposes until residential subdivision takes place. This type of land is also referred to as ‘greenfield’.
The construction of a new dwelling (or beginning of).
A habitable residential building.
The supply of dwellings (either occupied or unoccupied) in a given geographic area.
Parents whose children have left the family home to establish new households elsewhere.
Estimated Resident Population (ERP)
This is the estimate of the population based on their usual residence. The ERP at the time of the Census is calculated as the sum of the enumerated (counted) population plus persons temporarily absent less persons who are non-permanent (visitor) residents. An undercount of population by small area at Census time is also accounted for. The ERP used in these forecasts is then backdated to June 30. The ERP for forecast years are based on adding to the estimated population the components of natural increase and net migration.
In this report, the forecast period is from 2016 to 2036. Most data on the website has focused on the period from 2016 to 2036 plus 15.
One or more persons living in a structural private dwelling.
Residential development based on increasing dwelling densities around suburb and town centres. Usually around existing transport nodes and service infrastructure, rather than developing previously undeveloped land on the urban fringe.
Residential development, usually of a relatively small scale, on redevelopment sites in established urban areas. This can take place on land previously used for another urban purpose such as industry or schools or on existing residential allotments where new dwellings are added. Also referred to as ‘intensification’ of existing areas.
One and two parent families with older children, generally of secondary and tertiary school age.
The movement of people or households from one location to another.
The increase in population based on the births minus deaths, not including the impact of migration.
Net household additions
The overall increase in occupied dwellings, determined by the level of new dwelling construction that is permanently occupied, or conversion of non-permanently occupied dwellings to permanently occupied minus demolitions.
These dwellings include persons resident in establishments such as prisons, student or nurses’ accommodation, nursing homes, boarding houses, military facilities, and hospitals.
The proportion of structural private dwellings that are occupied by a household.
Occupied Private Dwellings (OPD)
These are all Structural Private Dwellings (SPD’s) that are occupied by a household. Excluded are dwellings that were under construction, being demolished or where the house was temporarily vacant.
Self-contained dwelling including houses (attached or detached), flats, townhouses etc. Retirement village units are also private dwellings as are houses or flats rented from the government.
These are sites in already established areas not originally developed for residential uses, but identified for conversion to residential use. Examples include former school sites, quarries, derelict industrial land, former petrol stations and the like.
Structural Private Dwellings (SPD)
This is the stock of houses, flats, and other dwelling types. The SPD is the usual base stock from which commencements are added and demolitions deducted.
'Top down' forecast
Population forecast based on assumptions made at the State and National level and allocated into smaller regions e.g. Local Government Areas, suburbs.
The proportion of structural private dwellings that are not occupied by a household.
One and two parent families with young children, generally of pre and primary school age.