My Granny Flat Strategy: 10 Real Queensland Case Studies Revealed
The granny flat strategy is one of the most powerful tools available to Queensland property investors today. By adding a secondary dwelling to a standard residential block, investors can dramatically increase their rental yield, manufacture equity, and build a cash-flow-positive portfolio — often from day one.
Over the past several years, I have helped a number of clients across South East Queensland and beyond implement this exact strategy. This blog post reveals 10 real properties I sourced for clients, including purchase prices, granny flat costs, rental incomes, gross yields, and equity gains where bank valuations are available.
Note: These properties belong to different clients. Churchill, Deception Bay (Beaufort Place), and Caboolture (Gardenia Street) belong to the same client who built a three-property sub-portfolio. All other properties represent individual client purchases.
What Makes the Granny Flat Strategy So Effective in Queensland?
Queensland's planning framework has become increasingly supportive of secondary dwellings. In 2022, the Queensland Government removed the restriction requiring granny flat occupants to be family members of the primary dwelling's residents . This opened the rental market to a far broader pool of tenants.
The strategy generates two income streams from a single land title, producing gross yields well above the Queensland average for standard investment properties. For more on identifying the right properties, read our on-market vs off-market property guide.
The 10 Client Case Studies
Case Study 1: 9 Clementine Place, Bli Bli QLD 4560
Sunshine Coast Regional Council | Purchased March 2026
Metric
Value Purchase Price $943,706
Granny Flat Cost $155,000
Total Invested $1,098,706
Main / Granny Rent (pw) $720 / $500
Combined Weekly Rent $1,220
Gross Yield 5.77%
Bank Valuation $1,250,000
Equity Gain $151,294
Case Study 2: 7 Wills Street West, Nanango QLD 4615
South Burnett Regional Council
Metric
Value Purchase Price $477,500
Granny Flat Cost $160,000
Total Invested $637,500
Main / Granny Rent (pw) $520 / $500
Combined Weekly Rent $1,020
Gross Yield
8.32%
Case Study 3: 14 Upper Holborn Street, Deception Bay QLD 4508
Moreton Bay Regional Council | Purchased January 2026
Metric
Value Purchase Price $920,000
Granny Flat Cost $150,000
Total Invested $1,070,000
Main / Granny Rent (pw) $640 / $480
Combined Weekly Rent $1,120
Gross Yield 5.44%
Bank Valuation $1,350,000
Equity Gain $280,000 (26.2%)
Case Study 4: 66 Kent Street, Kallangur QLD 4503
Moreton Bay Regional Council | Purchased February 2021
The standout performer of the portfolio. Purchased for $396,000 with a $175,000 granny flat added, the bank valuation reached $1,265,000 by November 2025 — a 121.5% return on total invested capital.
Metric
Value Purchase Price $396,000
Granny Flat Cost $175,000
Total Invested $571,000
Main / Granny Rent (pw) $620 / $460
Combined Weekly Rent $1,080
Gross Yield 9.84%
Bank Valuation (Nov 2025) $1,265,000
Equity Gain $694,000 (121.5%)
Case Study 5: 10 Samaya Street, Burpengary QLD 4505
Moreton Bay Regional Council | Purchased July 2024
Metric
Value Purchase Price $600,000
Granny Flat Cost $165,000
Total Invested $765,000
Main / Granny Rent (pw) $640 / $460
Combined Weekly Rent $1,100
Gross Yield 7.48%
Bank Valuation $1,200,000
Equity Gain $435,000 (56.9%)
One Client's Three-Property Sub-Portfolio
One client built a granny flat sub-portfolio across Churchill, Deception Bay (Beaufort Place), and Caboolture (Gardenia Street). Combined, they invested $2,522,500, generate $3,330 per week in rent, and hold a combined bank valuation of $3,350,000 — a total equity gain of $827,500. Our rentvesting strategy guide covers how to structure borrowing to build a portfolio like this.
Case Study 6: 3 Churchill Street, Churchill QLD 4305
Ipswich City Council | Purchased October 2024 — granny flat already built
Metric
Value
Purchase Price (incl. granny flat) $695,000
Main / Granny Rent (pw) $620 / $460
Combined Weekly Rent $1,080
Gross Yield 8.08%
Bank Valuation $1,100,000
Equity Gain $405,000 (58.3%)
Case Study 7: 37 Zabel Road, Lockrose QLD 4342
Lockyer Valley Regional Council | Purchased August 2023 — granny flat already built
Metric
Value
Purchase Price (incl. granny flat) $625,000
Main / Granny Rent (pw) $580 / $440
Combined Weekly Rent $1,020
Gross Yield 8.49%
Bank Valuation $960,000
Equity Gain $335,000 (53.6%)
Case Study 8: 29 Beaufort Place, Deception Bay QLD 4508
Moreton Bay Regional Council
Metric
Value Purchase Price $705,000
Granny Flat Cost $150,000
Total Invested $855,000
Main / Granny Rent (pw) $580 / $495
Combined Weekly Rent $1,075
Gross Yield 6.54%
Bank Valuation $1,150,000
Equity Gain $295,000 (34.5%)
Case Study 9: 9 Gardenia Street, Caboolture QLD 4510
Moreton Bay Regional Council | Purchased January 2026
Metric
Value Purchase Price $822,500
Granny Flat Cost $150,000
Total Invested $972,500
Main / Granny Rent (pw) $680 / $495
Combined Weekly Rent $1,175
Gross Yield 6.28%
Bank Valuation (Apr 2026) $1,100,000
Equity Gain $127,500 (13.1%)
Case Study 10: 4 Hillcrest Avenue, Caboolture QLD 4510
Moreton Bay Regional Council | Purchased August 2026
Metric
Value Purchase Price $710,000
Granny Flat Cost $160,000
Total Invested $870,000
Main / Granny Rent (pw) $570 / $460
Combined Weekly Rent $1,030
Gross Yield 6.16%
Bank Valuation (May 2026) $1,050,000
Equity Gain $180,000 (20.7%)
Aggregated Portfolio Results
Metric Value Total Capital Deployed $8,159,706
Total Combined Weekly Rent $10,920
Total Annual Rental Income $567,840
Portfolio Gross Yield 6.96%
Properties with Bank Valuations 9 of 10
Total Bank Value (9 properties) $10,425,000
Total Equity Gain (9 properties)
$2,902,794
Across nine properties with confirmed bank valuations, clients have collectively gained $2,902,794 in equity. The portfolio generates $567,840 per year in rent across six Queensland council areas. Explore high-performing locations in our suburb reports hub.
Key Lessons from These 10 Case Studies
Buying with an existing granny flat accelerates returns. Churchill and Lockrose both came with secondary dwellings in place, delivering dual income from settlement day and strong equity gains.
Lower purchase prices do not mean lower returns. Kallangur, purchased for $396,000, delivered the highest yield (9.84%) and largest equity gain ($694,000) in the entire portfolio.
Moreton Bay consistently performs. Five of the 10 properties sit within the Moreton Bay Regional Council area, reflecting the region's strong population growth, affordability, and rental demand.
Construction costs have remained stable. Across the eight properties where a granny flat was built, costs ranged from $150,000 to $175,000 — enabling reliable feasibility modelling before purchase.
Frequently Asked Questions
Do I need council approval to build a granny flat in Queensland?
Yes. All new secondary dwellings require building approval, and depending on your council, development approval may also apply . Check with your local council before purchasing.
Can I rent a granny flat to a non-family member in Queensland?
Yes. Since 2022, Queensland law allows secondary dwellings to be rented to anyone . This significantly expanded the available tenant pool for investors.
How much does it cost to build a granny flat?
Based on this portfolio, quality granny flat construction typically costs between $150,000 and $175,000, depending on size, specifications, and site conditions.
Does a granny flat increase the bank valuation?
In every case in this portfolio with a post-construction bank valuation, the valuation exceeded total invested capital — with gains ranging from $127,500 to $694,000.
Is it better to buy with an existing granny flat or build one?
Both work well. Buying with one already built delivers immediate dual income. Building new allows you to design for maximum rental appeal. The right choice depends on your timeline, budget, and the specific opportunity.
