How a measure is made · Rents by area
The median of new bonds, and the mix of homes let
Most rents on the area pages are a median of new bonds: the middle weekly rent of the bonds lodged for homes newly let in a period. This page says whose median each state's is, why a median can move when no rent has changed, and what each area page does about that.
Used on every area page with a median of new bonds: Rents and sale prices by area. The rent check page uses NSW postcodes' medians and quartiles, by kind of home, when the city chosen is Sydney. Through DwellDelta's MCP server, rent_check can also place a rent against one place's median of new bonds in New South Wales, Victoria, Queensland, Western Australia, South Australia or Tasmania.
What the figure is
- A bond is lodged when a home is newly let. The median is the middle weekly rent of the bonds lodged in the period: at least half were lodged at or below it, and at least half at or above it. Tasmania's counts private-housing bonds only: community-housing bonds are left out. Western Australia's and Tasmania's records do not say whether a bond is for a new tenancy: DwellDelta takes each lodgement to be one, and those files say so.
- Where DwellDelta calculates the median and the number of bonds is even, it is halfway between the two middle rents. Tasmania's is given to the cent.
- It is a figure for newly let homes only. It is not an advertised rent, and not what sitting tenants pay.
- Victoria's median is of the leases begun in the 12 months to the quarter, not in the quarter alone. Tasmania's is of one month's bonds.
- A median needs enough bonds. Western Australia's and Tasmania's need 10 in the period, and New South Wales's publisher reports nothing for 10 or fewer: there a page shows a gap, never zero. South Australia's publisher shows a median even for 1 to 5 bonds, with no count; no area page is built for those.
Whose figure it is
Some medians are the publisher's own. Some are calculated by DwellDelta from the publisher's figures, where the publisher gives one record per bond and no median. Most files say which in their own changes_made field.
| Where | The median | Its change on a year |
|---|---|---|
| New South Wales | The publisher's own (DCJ) | The publisher's own |
| Victoria | The publisher's own (Homes Victoria), over 12 months | Calculated by DwellDelta from the publisher's figures |
| Queensland | The publisher's own (RTA) | Calculated by DwellDelta from the publisher's figures |
| Western Australia | Calculated by DwellDelta from the publisher's figures | Calculated by DwellDelta from the publisher's figures |
| South Australia | The publisher's own (SA Housing Trust) | Calculated by DwellDelta from the publisher's figures, when a year-earlier workbook is held |
| Tasmania | Calculated by DwellDelta from the publisher's figures, one month | None, while one month is held |
| New Zealand | The publisher's own (MBIE), in New Zealand dollars | None today: DwellDelta still treats MBIE's figures as provisional, and the file says why. When one is given, it is calculated by DwellDelta from MBIE's medians |
The files: nsw-rents.json, vic-rents.json, qld-rents.json, wa-rents.json, sa-rents.json, tas-rents.json and nz-rents.json.
Wherever DwellDelta calculates a change on a year, it is (this period's median ÷ the median a year before − 1) × 100, to one decimal place.
The mix effect
Why a median can move when no rent has
A median is the middle of whichever homes were let. If more of one kind of home is let in one period than in the last, the middle moves, even if every home is let for what it was before.
| Period | Flats let at $500 a week | Houses let at $800 a week | Bonds | Median |
|---|---|---|---|---|
| First quarter | 6 | 5 | 11 | $500 a week |
| Next quarter | 5 | 6 | 11 | $800 a week |
No home's rent changed. One more house and one fewer flat were let, and the median rose from $500 to $800, by 60%. The same arithmetic applies to every median: a rise or fall can be new apartments, more large houses or more rooms let, and not the same homes costing more.
What each area page does about it
- It says so first. In New South Wales, Victoria, Western Australia, South Australia and Tasmania, each "How the place compares" section that has a rent median begins: "All dwellings together: a place let mostly as flats sits below one let mostly as houses, so a gap, rank or change here can be the mix of homes let, not their rents." Queensland's pages say it in their own words, with its rooming accommodation.
- It sets like beside like. In New South Wales and Queensland, the table of the homes most often let sets up to six of the place's dwelling types and sizes beside the state's same type and size, leaving out every small sample on either side.
- It compares changes with care. A place's change on a year is set beside its state's (in Victoria, its region's) only where the place's figure is no small sample. Within 1 percentage point, the two are called about the same change.
- It compares like periods. Where DwellDelta calculates a change on a year, it sets a quarter beside the same quarter a year before (Victoria: the 12 months to a quarter beside the 12 months to the same quarter; Tasmania: a month beside the same month), so the time of year is the same on both sides. New South Wales's change is DCJ's own annual change, which its file sets against the same quarter a year before.
- It pools a region's bonds. Greater Perth's median is the median of the individual bonds lodged in its localities, not a median of its localities' medians.
- It stays within one state. No figure is added, averaged or ranked across states.
Straight about the data
What this cannot tell you
- What any one home rents for, or should rent for.
- Whether the same homes' rents rose: a median of new bonds cannot say.
- The ABS rents index is a different measure, of what tenants pay across new and continuing leases: The ABS rents index, and the median of new bonds.
- Information, not financial or tenancy advice.
Where this is in DwellDelta's code
DwellDelta's code is not public. The names below let anyone who holds it check this page. The tests named last check that each name below in DwellDelta Tools exists, and hold to the code and the files which medians the table calls calculated by DwellDelta, New Zealand's change, the change formula and the made-up example. The names in DwellDelta's data repository were checked by hand when these words were written, against a recorded version of that repository, not at each build.
- The area pages' comparisons:
tools/render-area-pages.mjsin DwellDelta Tools,MIX,LIKE,SAME_CHANGE,pace(),compare()andALWAYS_CALCULATED. - Western Australia's medians and changes:
tools/macro/wa_rents.pyin DwellDelta's data repository,summary(),build()andgreater_perth(); Victoria's changes:tools/macro/vic_rents.py; Queensland's:tools/macro/qld_rents.py,build(); South Australia's:sa_row()intools/build_state_rents_feeds.py. - Tasmania's medians:
tools/macro/tas_rents.py,figure(). - Each file's
changes_madeand limits:tools/build_state_rents_feeds.py,tools/build_vic_rents_feed.py,tools/build_tas_rents_feed.pyandtools/build_nz_rents_feed.py. - This page and its tests:
methodPages()intools/render-area-pages.mjs, its words intools/method-words.mjs, andtests/method-pages.test.mjsin DwellDelta Tools.