By name: sg-property-analyst description: Singapore property market domain expertise. Use when making decisions about data interpretation, market terminology, URA data handling, property classifications, or bedroom sizing.
Singapore Property Market Expert
Domain knowledge for interpreting Singapore property market data correctly.
Trigger: Market terminology, bedroom classification, district/region decisions, URA data quirks, deal ratings
Market Segmentation
Core Central Region (CCR) - Prime Districts
D01: Boat Quay / Raffles Place / Marina
D02: Shenton Way / Tanjong Pagar
D06: City Hall / Fort Canning
D07: Bugis / Rochor
D09: Orchard / Somerset / River Valley
D10: Tanglin / Bukit Timah / Holland
D11: Newton / Novena
Characteristics: Highest PSF, luxury market, more freehold/999-year, lower volume
Rest of Central Region (RCR) - City Fringe
D03: Queenstown / Alexandra / Tiong Bahru
D04: Harbourfront / Keppel / Telok Blangah
D05: Buona Vista / Dover / Pasir Panjang
D08: Little India / Farrer Park
D12: Balestier / Toa Payoh
D13: Potong Pasir / MacPherson
D14: Geylang / Paya Lebar / Eunos
D15: East Coast / Marine Parade / Katong
D20: Bishan / Ang Mo Kio
Characteristics: Mid-range, good connectivity, mix of tenure types
Outside Central Region (OCR) - Suburban
D16-D19: East (Bedok, Changi, Tampines, Pasir Ris, Serangoon, Hougang, Punggol)
D21-D28: West/North (Bukit Timah, Jurong, Bukit Batok, Woodlands, Yishun, Seletar)
Characteristics: Most affordable, highest volume, predominantly 99-year
Bedroom Classification (Three-Tier System)
Why three tiers? AC ledge harmonization in June 2023 changed how floor area is measured. Post-harmonization units appear smaller for the same bedroom count.
Tier 1: New Sale >= June 2023 (Post-Harmonization)
1-Bedroom: < 580 sqft
2-Bedroom: 580 - 780 sqft
3-Bedroom: 780 - 1150 sqft
4-Bedroom: 1150 - 1450 sqft
5-Bedroom+: >= 1450 sqft
Ultra-compact sizing after AC ledge rules changed.
Tier 2: New Sale < June 2023 (Pre-Harmonization)
1-Bedroom: < 600 sqft
2-Bedroom: 600 - 850 sqft
3-Bedroom: 850 - 1200 sqft
4-Bedroom: 1200 - 1500 sqft
5-Bedroom+: >= 1500 sqft
Modern compact sizing with AC ledges counted.
Tier 3: Resale (Any Date)
1-Bedroom: < 600 sqft
2-Bedroom: 600 - 950 sqft
3-Bedroom: 950 - 1350 sqft
4-Bedroom: 1350 - 1650 sqft
5-Bedroom+: >= 1650 sqft
Legacy larger sizes from older developments.
Code: backend/services/classifier.py - classify_bedroom_three_tier()
URA Data Quirks
Month-Level Transactions
All URA transaction dates are 1st of month. There is no day-level granularity.
# WRONG: "Last 90 days"
date_from = today - timedelta(days=90)
# CORRECT: "Last 3 calendar months"
date_from = date(max_date.year, max_date.month - 2, 1)
Exclusive Date Bounds
Date ranges use exclusive upper bound to avoid double-counting at month boundaries.
WHERE transaction_date >= :date_from
AND transaction_date < :date_to_exclusive -- NOT <=
Sale Types
| Sale Type | Meaning |
|---|---|
| New Sale | Initial purchase from developer |
| Resale | Secondary market (owner-to-owner) |
| Sub Sale | Sale before TOP (Temporary Occupation Permit) |
Tenure Types
| Tenure | Meaning |
|---|---|
| Freehold | Perpetual ownership |
| 999-year | Effectively freehold |
| 99-year | Leasehold (most common) |
Timeframe Resolution
Canonical timeframe IDs (backend resolves to dates):
| ID | Period | Label |
|---|---|---|
| M3 | 3 months | 3M |
| M6 | 6 months | 6M |
| Y1 | 12 months | 1Y (default) |
| Y3 | 36 months | 3Y |
| Y5 | 60 months | 5Y |
Rule: Frontend sends ID, backend resolves to date_from and date_to_exclusive.
Deal Rating Framework
Percentile-Based Rating
Compares unit PSF against distribution:
| Rating | Percentile | Meaning |
|---|---|---|
| Good | < 25th | Below market average |
| Fair | 25th - 75th | At market |
| High | > 75th | Above market average |
Comparison Levels
- Project-level: vs other units in same project
- District-level: vs all transactions in district
- City-wide: vs all Singapore transactions
Exit Risk & Liquidity
Transaction Velocity
Measures market health based on transactions per 100 units:
| Velocity | Level | Meaning |
|---|---|---|
| < 5 txn/100 units | Low | Illiquid, harder to sell |
| 5 - 15 txn/100 units | Healthy | Normal market |
| > 15 txn/100 units | Elevated | High turnover (investigate why) |
Price Metrics
PSF (Price per Square Foot)
Primary comparison metric. Normalizes for unit size.
PSF = Transaction Price / Floor Area (sqft)
Median vs Average
- Median: Resistant to outliers, preferred for market summaries
- Average: Useful for total volume calculations
Outlier Handling
Transactions are flagged as outliers using IQR method at data ingestion. Every query MUST exclude outliers:
WHERE COALESCE(is_outlier, false) = false
Common Data Questions
"Why do bedrooms seem wrong?"
Check sale type and date. A 750 sqft "2-bedroom" is correct for:
- Tier 1 (post-Jun 2023 new sale): 580-780 sqft = 2BR
- Tier 3 (resale): 600-950 sqft = 2BR
"Why are there gaps in monthly data?"
URA updates semi-annually (H1/H2). Recent months may have incomplete data until next release.
"Why does filter show no transactions?"
Check:
- Date range - URA data starts from specific year
- Combination rarity - some district+bedroom combos have few transactions
- Outlier exclusion - transactions may be filtered as outliers
"Why is median different from what I calculated?"
Ensure:
- Same date range (exclusive upper bound)
- Same outlier exclusion
- Same bedroom classification tier
- Same sale type filter