ADU Pass
Mockingbird Finance
Also known as Mockingbird Station, SMU area, University Park, Highland Park, Lower Greenville, M Streets, Park Cities, Mockingbird Lane
ADU Pass helps homeowners in Mockingbird Finance — a USPS locale inside Dallas, Dallas County, Texas — navigate the permit paperwork for building an accessory dwelling unit. This locale covers 1 ZIP code.
Map
Locale-specific ADU details
Site (parcel physics)
Slope:
Soil:
Lot profile:
Geo-hazards:
Recent ADU permit activity
Utility capacity (upgrade likelihood)
Housing stock age:
Electric service drop:
Sewer lateral:
Water pressure:
Gas availability: available — Natural gas service is fully available from Atmos Energy. Dallas has no Berkeley-style all-electric mandate, so a new ADU may include gas heat / hot water / range. Many new-construction projects in this corridor are still installing gas lines because the existing primary is gas-served.
Locale property values
Locale value runs roughly 2.3 times the Dallas citywide median ($295,300) because the Dallas-side 75206 and 75205 blocks are a mature high-desirability corridor. Property-tax effective rate is the same Dallas County composite rate (City of Dallas + DCAD + DISD + hospital + community college).
Locale market rent
| Sq ft | Rent |
|---|---|
| 400 | $1,550/mo |
| 600 | $1,875/mo |
| 800 | $2,175/mo |
Locale overlays (3)
- historic-district — M-Streets (Greenland Hills) Conservation District CD-2 covers the Mercedes / Matalee / Morningside / McCommas / Monticello blocks immediately south of Mockingbird Ln in ZIP 75206. Parcels in CD-2 require a Certificate of Appropriateness from the Dallas Landmark Commission for any exterior-visible new construction, including a detached ADU. · +45d · +10% cost
CD-2 design guidelines focus on preserving 1920s-1940s Craftsman / Tudor / Spanish Colonial Revival character. ADU exteriors must use compatible massing, materials, and rooflines. Review is by the Landmark Commission, typically a 30-60 day process. - airport-noise-zone — Dallas Love Field AICUZ (Air Installations Compatible Use Zones) touches the western edge of this area. Parcels closer to Love Field (western 75205/75235 border) sit within 65-DNL and 70-DNL contours requiring sound-attenuation construction.
Most of the Mockingbird Finance service area is east of Love Field's 65-DNL contour and does not trigger noise mitigation; parcels west of Inwood Rd in 75235-adjacent 75205 should verify before submittal. - other — University / SMU campus edge: parcels immediately adjacent to SMU (bordering Bishop Blvd / Mockingbird / Airline) sometimes have Planned Development overlays tied to the university's master plan; individual parcel zoning should be confirmed via the Dallas GIS map.
The PD overlays generally affect the campus itself and commercial edges, not the single-family residential blocks eligible for ADUs under Sec. 51A-4.510.
Inherited from the city
These sections come from the city page. Click through to the Dallas ADU research for details.
- ADU legality
- legal history
- size range
- permitting process & fees
- permit forms
- contacts
- utilities
- incentives
- viability
- resale value impact
- construction timeline
- pre-approved plans
- financing
- insurance impact
- service complexity
Dallas — city ADU rules and incentives
ADU legality: unclear
Texas leaves ADU regulation to local municipalities under home-rule or Dillon-rule authority. Dallas permits ADUs subject to local conditions per its zoning ordinance.
City cost envelope
$117,300 all-in for a 525 sqft ADU (permit + build). Midpoint scenario.
Permit fee bundle: $2,905 (2026-04).
City viability (selected uses)
Dallas County — county ADU rules and overlays
County regulatory overlays
Dallas County's county-level overlays apply only inside its small unincorporated footprint (under 10% of county land, primarily southeastern Dallas County). The two material overlays at county scope are FEMA-mapped Special Flood Hazard Areas administered by Dallas County Public Works under the county's floodplain ordinance, and the countywide Trinity Common Vision Program governing floodplain management along the Trinity River corridor. Inside incorporated cities — where the vast majority of Dallas County residents and ADU-candidate parcels sit — overlay administration is a city function (e.g., the City of Dallas administers its own Escarpment Zone at Dallas Development Code Art. V and its own Floodplain regulations at Div. 51A-5.100). There is no countywide WUI / wildland-fire hazard overlay of the kind seen in California or Washington; North Texas's fire-hazard regime is ESD-by-ESD rather than a county-administered WUI zone.
- Dallas County Floodplain Management (FEMA NFIP participation) — A new ADU in a Zone AE parcel must be elevated to or above the Base Flood Elevation per the county ordinance and is generally not permitted as a basement or ground-floor sleeping space.
- Trinity Common Vision Program — Structures including ADUs proposed within the Common Vision corridor face stricter review than FEMA NFIP alone and may require a No-Rise Certificate from a Texas-licensed engineer.
- On-Site Sewage Facility (OSSF) jurisdiction — An ADU counts as an additional dwelling for OSSF sizing purposes, which can trigger system expansion on undersized lots and may be infeasible on very small unincorporated parcels.
County permitting (unincorporated parcels)
Dallas County regulates construction in unincorporated areas through the Department of Unincorporated Area Services (DUAS), in partnership with the Dallas County Fire Marshal's Office and Public Works. Because the county has no zoning authority (see countyOrdinance), DUAS does not restrict whether an ADU may be built — it regulates only subdivision/plat compliance, residential building-code inspection, on-site sewage (OSSF) compliance, floodplain compliance, 911 addressing, and nuisance abatement. A detached secondary dwelling on an unincorporated parcel is permitted as an ordinary residential structure through DUAS's building-permit pathway; there is no separate 'ADU permit' because there is no county use category for accessory dwellings. Unincorporated Dallas County comprises under 10% of county land area, primarily in the southeastern corner of the county. Most ADU activity in Dallas County occurs in incorporated cities (notably the City of Dallas ADU Overlay at Dallas Development Code Sec. 51A-4.510), which are governed by city-level permitting, not this section.
Texas state — ADU law and programs
State ADU law
Texas has NOT enacted a statewide ADU preemption or ADU-by-right statute. Local governments (municipalities and counties) retain full authority over ADU zoning, setbacks, parking, size limits, owner-occupancy, and permitting. Two recent housing-reform bills in the 89th Legislature (2025) touch density and zoning procedure but do NOT preempt ADU-specific local rules: SB 15 (Bettencourt, signed 2025-06-20, effective 2025-09-01) caps minimum single-family lot sizes in cities over 150,000 in counties over 300,000, and HB 24 (signed 2025-06-20, effective 2025-09-01) raises the protest petition threshold for zoning changes. A dedicated ADU-preemption bill — SB 673 (Hughes, 2025) — passed the Texas Senate on 2025-04-10 and was reported favorably by the House Land & Resource Management Committee on 2025-05-08, but died on the General State Calendar when the 89th Regular Session adjourned on 2025-06-02. In the absence of a state ADU statute, homeowners must consult the ordinance of the municipality (or the county's subdivision rules for unincorporated areas) where the lot sits.
- Texas SB 15 (89R, 2025) — Relating to size and density requirements for residential lots in certain municipalities; authorizing a fee — Prohibits municipalities of population greater than 150,000 located in counties of population greater than 300,000 from imposing minimum lot sizes greater than a specified threshold (3,000 sqft for certain residentially zoned subdivisions; lower for new subdivisions) and limits their authority over setbacks, parking, permeable-surface, and height on those lots. Not ADU-specific, but functionally expands the footprint of small-lot single-family housing in Austin, Dallas, Fort Worth, Houston, San Antonio, and other qualifying cities. Signed 2025-06-20; effective 2025-09-01.
- Texas HB 24 (89R, 2025) — Relating to procedures for changes to a zoning regulation or district boundary — Raises the protest-petition threshold for neighboring property owners who wish to trigger a supermajority city-council vote on a rezoning from 20% to 60%, and constrains the ability of a small minority to block citywide zoning updates. Not ADU-specific; affects the procedural posture of any city-wide ADU-enabling rezoning. Signed 2025-06-20; effective 2025-09-01.
State financing programs
Texas does not operate an ADU-specific statewide loan, grant, or forgivable-loan program comparable to California's CalHFA ADU Grant. The Texas Department of Housing and Community Affairs (TDHCA) administers the state's general housing finance programs — My First Texas Home, My Choice Texas Home, Mortgage Credit Certificates, multifamily Housing Tax Credits, the Homeowner Assistance Fund, and Housing Trust Fund awards. None target ADU construction directly, but several can apply to an ADU as part of a primary-residence purchase or refinance when program criteria are met. ADU-specific financing in Texas is primarily local: the City of Austin's ADU Loan Program (administered through Neighborhood Housing and Community Development) and a handful of smaller pilot programs are the most visible, but these sit at the city tier, not the state tier.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Code
- 75219
Post Office
- 4740 W Mockingbird Ln Ste C, 75209