Methodology
How we calculate SDA investment signals from official NDIS housing data — and what they mean for investors.
Data Source
All figures are derived from the NDIA SDA Enrolled dwellings and NDIS demand data quarterly releases. This is official government data published by the National Disability Insurance Agency.
We do not scrape third-party websites, make estimates, or use machine learning predictions. Every number you see comes directly from NDIS data.
How SDA Places Are Calculated
The NDIA publishes enrolled SDA dwelling counts by SA3 region, broken down by maximum number of residents (1, 2, 3, 4, 5, or 6+ residents per dwelling). We calculate total places — the maximum physical capacity — by multiplying the number of dwellings in each category by the maximum number of residents they can accommodate.
Example: If a region has 10 dwellings for 1 resident, 5 for 2 residents, and 3 for 3 residents, total places = (10 × 1) + (5 × 2) + (3 × 3) = 29 places.
Important nuance: Not all places are economically equivalent. SDA provider income per place depends on the participant's funded building type and design category. Under the NDIA's "lower of" rule, providers receive the lesser of the participant's plan SDA funding amount or the dwelling's enrolled maximum per-participant price. If a participant's funding does not match the dwelling type, the provider receives the lower amount. Our places figure represents physical capacity, not economic capacity.
Supply/Demand Gap Calculation
Formula: SDA Places − Total Demand (in use + eligible)
- Positive value (Oversupply): More SDA places available than eligible participants. May indicate difficulty filling vacancies.
- Negative value (Shortfall): More eligible participants than SDA places. May indicate unmet demand.
- Zero (Balanced): Supply roughly matches demand.
Utilisation Rate
Formula: Participants Currently Using SDA ÷ Total SDA Places
- High (70%+): Most places are occupied. Indicates strong demand and successful tenant matching.
- Medium (50-70%): Moderate occupancy. Some mismatch or developing market.
- Low (<50%): Many vacant places. May indicate oversupply or mismatch between available housing and participant needs.
Market Assessment Classifications
Undersupplied – Strong Opportunity
High gap between eligible participants and available places. Strong demand signal.
First Mover – Strategic Opportunity
No SDA places yet, but eligible demand exists. Early-stage land opportunity.
Moderately Undersupplied – Monitor
Some shortfall exists. Watch closely and consider land banking or early planning.
Balanced
Supply and demand are roughly aligned. Only build with pre-commitment.
Potential Oversupply – Caution
More SDA places than demand. Avoid new builds. Focus on filling vacancies.
Confidence Score
The confidence score adjusts the market assessment based on utilisation rate:
- High: Utilisation above 70%. Assessment aligns with strong market activity.
- Medium: Utilisation 50-70%, or early-stage market. Validate before acting.
- Low: Utilisation below 50%. Despite apparent demand signals, there may be mismatch or saturation risk.
Design Category Breakdown
The NDIA publishes SDA demand and dwelling counts broken down by design category: Improved Liveability, High Physical Support, Robust, Fully Accessible, and Basic (legacy category — no longer available for new builds).
Because the per-category data does not include a resident-count breakdown, we estimate places at the national average of 2.3 residents per dwelling, rounded down to the nearest whole number. The shortfall for each category is then calculated as demand minus estimated places.
This estimate is less precise than the region-level places figure (which uses actual resident-count data), but it provides a useful directional signal for which design categories are undersupplied in a given region.
Build Type Breakdown
We also present a breakdown of enrolled SDA dwellings by build type: Existing, New Build, New Build (Refurbished), and Legacy.
Legacy dwellings are properties enrolled before the current SDA framework and are being phased out over time. The build type mix indicates how mature the SDA supply in a region is and whether new stock is entering the market.
Limitations & Caveats
- Data is updated quarterly by the NDIS. Market conditions may change between releases.
- Pipeline data (under-construction dwellings) is not included in current supply counts.
- Some participants may have design category data missing or misclassified.
- Regional data at SA3 level may not capture local variations within suburbs.
- Places represent physical capacity. Actual provider income varies based on the match between a participant's funded building type/design category and the dwelling's enrolled classification.
- Design category places are estimated using a national average (2.3 residents per dwelling) and may not reflect actual resident counts in specific categories or regions.
- The AI Investment Advisor uses third-party AI technology. Its responses may contain inaccuracies and should not be relied upon without independent verification.
- This tool provides market information only and does not constitute investment advice.