Population and Growth Modelling
Population growth has been occurring throughout the Selwyn district, but the lion's share is in the 'commuter belt', close to Christchurch, and is addressed by the Greater Christchurch Partnership. This high-growth area includes West Melton, Rolleston, Lincoln, Springston, Prebbleton, Tai Tapu and many rural "lifestyle blocks".
Stats NZ has good population statistics, including Population Estimates and Population and Household Projections.
The Council has been maintaining a Growth Model to predict future residential and business development across the district. Growth modelling helps us plan to ensure there is sufficient infrastructure and zoned land in the right location at the right time.
Our Growth Model spatially identifies capacity by analysing a variety of data and making assumptions around the type of new development needed.
Growth Model Data inputs
The following data is used as an input into our Growth Model:
- District Plan Zoning Layers and Building Envelope Rules
- Rating Database (Land Value, Capital Value, Number of Dwellings, Typology, GFA, Dwelling Age) [ZIP, 6336 KB]
- Land Development Cost Assumptions [PDF, 459 KB]
- Build Development Cost Assumptions [PDF, 2316 KB]
- Sales Data - Data requested from QV
- Stats NZ Population Estimates and Projection Assumptions (See Stats NZ)
Groth Model Assumptions
The following report by Formative [PDF, 1214 KB] outlines the modelling process we follow. The assumptions made in our Growth Model are:
- The Site sizes that relate to what the District Plan enables (e.g. Plan-enabled) and what could be reasonably expected to be realised, which is based on recent subdivision consent and market expectations.
- The Profit margins for feasibility calculation
- The Population and household projection assumptions
- The Dwelling utilisation
- What sites to include as developable urban land and property (e.g. not council owned)
- The Long-term changes in construction costs and house sales price
The following spreadsheet [PDF, 145 KB] and report contains the outputs of the model following the update in February 2023.
If you have any questions please contact the Duty Planner on Phone 0800 SELWYN (735 996) or email email@example.com