GUIDE 02 - 2027 EDITION
ADU Profit Calculator in TX, NC, and FL
Texas, Florida & North Carolina (2027)
Model what an accessory dwelling unit may cost to build and what it may earn, by size and state, from 600 to 1,200 sq ft.
TX
8-
17%
FL
8-
14%
NC
8-
13%
Estimated annual ROI, 600 sq ft ADU
Important Note: The information in these guides is for general reference only. A licensed Professional Engineer should review any actual design or construction work. JRH Engineering assumes no responsibility for the application or use of these materials.
TX - 2027
ADUs in Texas
A 600 sq ft ADU in Texas typically costs $260-$365 per sq ft to build, plus $8,300-$15,600 for permitting and engineering. Modeled rent is $1,850-$2,700 per month, with an estimated annual ROI of 8% -17% after a 5% vacancy allowance.
ADU Size sq ft | Construction Cost per sq | Permitting and Engineering | Monthly Rent | Annual ROI | Vacancy Rate percent | Property Tax Increase |
|---|---|---|---|---|---|---|
600 | $260 - $365 | $8,300 - $15,600 | $1,850 - $2,700 | 8.00% - 17.00% | 5.00% | $520 - $1,250 |
800 | $250 - $345 | $9,350 - $17,700 | $2,300 - $3,100 | 8.00% - 16.00% | 5.00% | $730 - $1,560 |
1000 | $240 - $335 | $10,400 - $19,750 | $2,700 - $3,550 | 8.00% - 15.00% | 5.00% | $940 - $1,870 |
1200 | $230 - $325 | $11,450 - $21,850 | $3,100 - $3,950 | 8.00% - 15.00% | 5.00% | $1,145 - $2,080 |
Updated 2027 • Construction costs uplifted ~ 4% • Rents held conservative • Verify local market rents and taxes
Texas notes & assumptions
01
Construction cost per sq ft uplifted ~ 4% from 2026. Includes typical finishes for a rental ADU.
02
Permitting and engineering includes civil and structural soft costs from the Soft Cost Estimator (ADU row).
03
ROI is approximate annual cash-on-cash before debt service. Actual returns vary with financing, vacancy and management
04
Property tax increase is the estimated incremental annual tax. Confirm with the local appraisal district.
05
Always obtain a current survey, geotech if soils are expansive, and local ADU ordinance compliance. JRH provides sealed plans.
FL - 2027
ADUs in Florida
A 600 sq ft ADU in Florida typically costs $290-$395 per sq ft to build, plus $9,350-$16,650 for permitting and engineering. Modeled rent is $2,080-$2,910 per month, with an estimated annual ROI of 8%-14% after a 5% vacancy allowance.
ADU Size sq ft | Construction Cost per sq | Permitting and Engineering | Monthly Rent | Annual ROI | Vacancy Rate percent | Property Tax Increase |
|---|---|---|---|---|---|---|
600 | $290 - $395 | $9,350 - $16,650 | $2,080 - $2,910 | 8.00% - 14.00% | 5.00% | $625 - $1,455 |
800 | $280 - $375 | $10,400 - $18,700 | $2,500 - $3,330 | 9.00% - 15.00% | 5.00% | $830 - $1,770 |
1000 | $270 - $365 | $11,450 - $20,800 | $2,910 - $3,740 | 10.00% - 16.00% | 5.00% | $1,040 - $2,080 |
1200 | $260 - $355 | $12,500 - $22,900 | $3,330 - $4,160 | 11.00% - 17.00% | 5.00% | $1,250 - $2,390 |
Updated 2027 • FBC 9th Edition • Higher construction costs due to wind/impact requirements • ~ 4% uplift
Florida notes & assumptions
01
Construction costs run higher than TX/NC due to wind design, impact openings and product approvals under the 9th Edition FBC.
02
Permitting and engineering includes elevated wind analysis and potential elevation certificate work.
03
ROI is approximate. Coastal or HVHZ locations will have higher soft and hard costs.
04
Confirm local ADU regulations, flood zones and HOA restrictions. JRH handles full structural and civil packages.
NC - 2027
ADUs in North Carolina
A 600 sq ft ADU in North Carolina typically costs $270-$375 per sq ft to build, plus $7,300-$13,500 for permitting and engineering. Modeled rent is $1,770-$2,500 per month, with an estimated annual ROI of 8%-13% after a 6% vacancy allowance.
ADU Size sq ft | Construction Cost per sq | Permitting and Engineering | Monthly Rent | Annual ROI | Vacancy Rate percent | Property Tax Increase |
|---|---|---|---|---|---|---|
600 | $270 - $375 | $7,300 - $13,500 | $1,770 - $2,500 | 8.00% - 13.00% | 6.00% | $415 - $1,040 |
800 | $260 - $355 | $8,300 - $15,600 | $2,185 - $2,910 | 9.00% - 14.00% | 6.00% | $625 - $1,350 |
1000 | $250 - $345 | $9,350 - $17,700 | $2,600 - $3,330 | 10.00% - 15.00% | 6.00% | $830 - $1,665 |
1200 | $240 - $335 | $10,400 - $19,750 | $3,020 - $3,740 | 11.00% - 16.00% | 6.00% | $1,040 - $1,975 |
Updated 2027 • ~ 4% uplift • Slightly higher vacancy assumption • Watershed and septic considerations
North Carolina notes & assumptions
01
Construction costs uplifted ~4%. Piedmont clay and frost depth can affect foundation costs.
02
Septic system capacity and perc tests are often required. Watershed rules may limit impervious area.
03
Vacancy is assumed slightly higher (6%). Confirm the local rental market.
04
JRH coordinates health department, zoning and structural design for ADUs.
Frequently Asked Questions
What does it cost to build an ADU in Texas, and what is the expected ROI in 2027?
A 600 sq ft ADU in Texas typically costs $260.00–$365.00 per sq ft to build, plus $8,300–$15,600 for permitting and engineering. Modeled rent is $1,850–$2,700 per month, with an estimated annual ROI of 8%–17% after a 5% vacancy allowance.
What does it cost to build an ADU in Florida, and what is the expected ROI in 2027?
A 600 sq ft ADU in Florida typically costs $290.00–$395.00 per sq ft to build, plus $9,350–$16,650 for permitting and engineering. Modeled rent is $2,080–$2,910 per month, with an estimated annual ROI of 8%–14% after a 5% vacancy allowance.
What does it cost to build an ADU in North Carolina, and what is the expected ROI in 2027?
A 600 sq ft ADU in North Carolina typically costs $270.00–$375.00 per sq ft to build, plus $7,300–$13,500 for permitting and engineering. Modeled rent is $1,770–$2,500 per month, with an estimated annual ROI of 8%–13% after a 6% vacancy allowance.
How current is this guide?
This guide was updated in October 2026 for 2027. Construction costs are uplifted roughly 4% from the 2026 baseline, and references reflect ASCE 7-22 and, for Florida, the Florida Building Code 9th Edition (effective December 31, 2026).
Can I use this guide for my specific project?
No. These figures are general reference ranges, not engineering advice. Always verify current local codes, fee schedules, design criteria and site conditions with the Authority Having Jurisdiction, and contact JRH Engineering for project-specific sealed designs, estimates and permit packages.
Disclaimer: These guides are for general reference only and are not engineering advice for any specific project. Verify current local codes, fee schedules and site conditions with the Authority Having Jurisdiction.
Proprietary reference material of JRH Engineering. Free for personal and professional use with attribution. Commercial redistribution prohibited without written permission.