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Sherman, TX Accessory Structures: ADU Rules (2026)

Significant Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified October 2026

ADU rules in Sherman, TX, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Minimum lot size: 12,000 square feet
Eligible zoning districts: R-A, R-E, R-12 or R-6
Units per lot: One accessory dwelling
Rear and interior side setback: At least five (5) feet
Separation from main building: At least 5 feet
Permit: Building permit and city inspection required

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Texas under recent ADU streamlining laws. The Sherman, TX rules below cover local size, height, and setback requirements.

Summary

In the City of Sherman, Texas, § 14.04.002(c)(5) allows an accessory dwelling only on a lot of at least 12,000 square feet zoned R-A, R-E, R-12 or R-6, with one accessory dwelling per lot. The unit is treated as an accessory building, so it needs a permit and must meet the siting setbacks.

(2) Accessory buildings attached to the primary building are considered an extension of the primary building and shall be subject to the regulations that apply to the primary building including, but not limited to, building setbacks. (3) Accessory buildings may be permitted within the allowable building area of any lot defined by the required front, side, and rear building lines. ... (5) An accessory building that serves as an accessory dwelling may not be located on a lot less than 12,000 square feet in area and shall be zoned R-A, R-E, R-12 or R-6 One accessory dwelling is allowed per lot. ... (9) The accessory building footprint shall be included in the calculation of the building area of the lot.

View official code

Full Breakdown

An accessory dwelling in the City of Sherman, Texas is defined in § 14.08.001 as a secondary dwelling unit established in conjunction with and clearly subordinate in size, location and use to a primary dwelling unit, whether part of the same structure or a detached unit on the same lot. The same definition states that an accessory dwelling is considered an accessory building, which pulls it into all of § 14.04.002.

Eligibility. Subsection (c)(5) bars an accessory dwelling from any lot of less than 12,000 square feet. The lot must also be zoned R-A, R-E, R-12 or R-6. One accessory dwelling is allowed per lot.

Siting. The unit must stay out of the front yard and out of the required side yard, and it must be separated from the main building by at least 5 feet. It needs a rear and interior side yard setback of at least five (5) feet. Beside a side street the minimum is fifteen (15) feet, except for garages or carports, and nothing can sit in a drainage or utility easement. An accessory building attached to the primary building is an extension of it and follows the regulations for the primary building, including building setbacks. Accessory buildings of 500 square feet or greater must be located in the building area, and the footprint of the accessory dwelling is included in the building area calculation for the lot.

Permits and use. Subsection (f) requires a building permit and city inspection. Under § 14.04.002(c)(4) and (c)(6), no accessory building can be rented or leased or used for commercial purposes. The section was last amended by Ordinance 6934 adopted 5/4/2026.

Violations & Fines

Building an accessory dwelling without a permit draws the administration fee set in appendix C plus the permit fees. Violating Chapter 14 is a class C misdemeanor under § 14.09.003, with a fine of not more than $2,000 and each day a separate offense, and the city can also seek a civil penalty of up to $1,000 per day.

Frequently Asked Questions

What lot size do I need for a garage apartment in the City of Sherman, Texas?

Subsection (c)(5) of § 14.04.002 says an accessory building that serves as an accessory dwelling may not be located on a lot less than 12,000 square feet in area. The lot also has to be zoned R-A, R-E, R-12 or R-6, and the code allows one accessory dwelling per lot.

Is an accessory dwelling in Sherman treated as a separate house?

No. Section 14.08.001 states that an accessory dwelling is considered an accessory building. It is therefore bound by the accessory building standards, including the five foot rear and interior side setbacks, the bar on front yard placement, and the building permit and inspection requirement in § 14.04.002(f).

Can I attach the accessory dwelling to my house in Sherman?

The definition covers a unit that is part of the same structure as the primary dwelling or a detached unit on the same lot. An accessory building attached to the primary building is treated as an extension of the primary building and follows the regulations for the primary building, including building setbacks.

Can an accessory dwelling be rented to a tenant in Sherman?

The code says no accessory building shall be rented or leased, and since an accessory dwelling is considered an accessory building, the ban reaches it. Subsection (c)(6) also forbids commercial use of an accessory building. No exception for accessory dwellings is printed in § 14.04.002.

Sources & Official References

[1]Sherman Code of Ordinances § 14.04.002 (eCode360)

Other rules in Sherman

Parking Rules: Overnight ParkingSome Restrictions Shed & Carport RulesSome Restrictions Parking Rules: RV & Boat ParkingSignificant Restrictions ADU Rental RestrictionsHeavy Restrictions Noise Ordinances: Vehicle NoiseSome Restrictions Parking Rules: Loading ZonesSome Restrictions Parking Rules: Commercial & Oversized VehiclesSignificant Restrictions Parking Rules: Driveway RulesSome Restrictions

All Sherman rules

How Sherman compares: Easiest Cities to Build an ADU·Texas rules heatmap·Compare Sherman to another location·View the Texas accessory structures overview

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