Killeen | Guest Houses and Duplexes
Killeen Guest Houses and Duplexes: What Replaces an ADU, and R-2 Two-Family Rules
An accessory dwelling unit, or ADU, is a second, smaller home on the same lot as a house. Killeen's zoning code, Chapter 31, has no ADU rule. Two large-lot districts allow a guest house that may not be rented, and the R-2 district allows a duplex, which is one building with two homes. This page covers both, the City's 2026 talks about ADUs and tiny homes, and the North Killeen program that waives fees. The Killeen overview gives the short version.
Killeen second units and duplexes in six facts
- The R-1 use list allows one-family dwellings and accessory buildings, and it names no second home. Source: Killeen Code, Sec. 31-186
- A-R1 and SR-2 allow one detached guest house per lot of up to 25 percent of the main home, and its rental or lease is prohibited. Source: Killeen Code, Secs. 31-172, 31-185.2
- R-2 allows a two-family dwelling on a lot of at least 7,000 square feet and 60 feet wide. Source: Killeen Code, Secs. 31-231, 31-233
- A duplex needs two off-street parking spaces for each home. Source: Killeen Code, Sec. 31-489
- A new two-family structure must include at least four of the 15 architectural elements in the design code. Source: Killeen Code, Sec. 31-904
- The FY 2027 building permit fee for a new single-family home, duplex or townhouse is $0.20 per square foot, with a $200 minimum. Source: City of Killeen FY 2027 Fee Schedule
What an R-1 Lot Allows
Sec. 31-186 lists what a building or premises in R-1 "shall be used only for." The first item is "One-family dwellings, including site-built and modular construction." The list goes on through churches, schools, parks and similar uses, then "Accessory buildings and uses, incident to the uses in this section and located on the same lot." No item names a second home, a garage apartment or an ADU. SR-1 and SF-2 point back to the R-1 list, so the same answer applies there.
Two other items in the R-1 list touch on living space. First, Sec. 31-186(13)(b) allows a private garage "with or without storeroom and/or utility room" as an accessory building, at least 25 feet from the front lot line, 5 feet from an interior side lot line and 10 feet from the rear lot line. It adds that "A garage or servants' quarters constructed as an integral part of the main building shall be subject to the regulations affecting the main building." Sec. 31-2 defines servants' quarters as living space "for servants employed on the premises and not rented or otherwise used as a separate domicile." So servants' quarters cannot serve as a rental unit.
Second, Sec. 31-186(17) allows "Short term rentals in accordance with" Article VII, which sets a permit for renting a home for 29 nights or fewer. The FY 2027 Fee Schedule lists the short term rental permit and inspection fee at $200 per unit and the renewal at $100 per year.
The code also limits who may share a home. Sec. 31-2 defines a family as people living together as one household "in which not more than three (3) adults are unrelated by blood, marriage, adoption, or guardianship."
Guest Houses in A-R1 and SR-2
Two districts list a guest house as a "Permitted Accessory Use": A-R1, the agricultural single-family district with one-acre lots (Sec. 31-172(b)), and SR-2, the suburban district with 15,000 square foot lots (Sec. 31-185.2(b)). The rules are the same in both:
- "One guest home per lot shall be permitted."
- "The guest house shall be a detached accessory use to a principal residence." Detached means it stands apart from the house.
- Its area may not exceed "twenty five (25) percent of the floor area of the principal residence (exclusive of garages)." For a 2,400 square foot house, that is 600 square feet, by VanPlex arithmetic.
- "One additional off-street parking space shall be required."
- "The rental or lease of a guest house shall be prohibited."
The last rule keeps a guest house as space for family or visitors. SR-1, the other suburban district, allows only the uses in Sec. 31-186 items (1) to (13)(b), and the guest house rule is absent there.
Any accessory building in a required rear yard must meet Sec. 31-474: no more than 20 feet tall, together no more than 25 percent of the rear yard area, and at least 5 feet from the main building, the rear lot line and the interior side lot lines. Eaves and roof extensions of sheds and accessory buildings may reach up to one foot into those setbacks. A building permit for an accessory building costs $80 under the FY 2027 schedule, plus the $10 tech fee.
The 2026 Talks on ADUs and Tiny Homes
On March 24, 2026 the City Council asked for an agenda item on "allowing tiny homes and accessory dwelling units (ADUs) in appropriate locations." Staff presented it on April 7, 2026 (item DS-26-030). The staff presentation made these points:
- The zoning ordinance "currently allows site-built or modular tiny homes on a permanent foundation by-right in residential districts," as the main home on a lot.
- A tiny home on wheels is built on a trailer chassis, and staff recommended rules to secure it to a permanent foundation and make it meet Appendix Q of the 2024 International Residential Code.
- "A common practice is to limit an ADU to a maximum square footage of 50% of the primary residence."
- Staff recommended an ordinance that would bring the North Killeen Revitalization Program into Chapter 31 and create an overlay "to allow Tiny Homes, Tiny Homes on Wheels (THOWS), and Accessory Dwelling Units (ADUs) by-right" inside the program boundary.
That is a staff recommendation. City Council records on Legistar through September 24, 2026 show no ordinance adopted on ADUs or tiny homes, and the codified Chapter 31 has no ADU section. In September 2026 the Council discussed other zoning changes, on data centers and short term rentals (item DS-26-088). Check with Development Services for any ADU ordinance adopted after this page was written.
Duplexes in R-2
Sec. 31-231 says a building in R-2 may be used for "Any use permitted in district 'R-1'" and for "Two-family dwellings." Sec. 31-2 defines a two-family dwelling as "a building designed for or occupied by two (2) families." For side yards, Sec. 31-473(c) treats a two-family dwelling "as one (1) building occupying one (1) lot," so both homes sit on one lot. The rules:
| R-2 rule | Requirement | Code |
|---|---|---|
| Lot area | 7,000 sq ft for a building of two homes | Sec. 31-233(b)(1) |
| Lot width | 60 ft at the front building line, and 60 ft on average | Sec. 31-233(b)(2) |
| Lot depth | 110 ft average; a corner lot at least 80 ft wide may be 80 ft deep | Sec. 31-233(b)(3) |
| Front yard | Same as R-1: 20 ft, with no parking in the required front yard | Secs. 31-233, 31-188 |
| Side yards | 7 ft each side; 15 ft beside a side street | Sec. 31-233(a)(2) |
| Rear yard | Same as R-1: 25 ft, measured from the centerline of the easement | Secs. 31-233, 31-188 |
| Height | Same as R-1: 35 ft or 2.5 stories | Secs. 31-232, 31-187 |
| Parking | 2 spaces per home | Sec. 31-489 |
Source: Killeen Code of Ordinances, Article IV, Divisions 4 and 7, and Sec. 31-489, Supplement 38 Update 1.
Older lots have a way in. Sec. 31-233(b)(4) lets a duplex go on a lot under 7,000 square feet that "existed and/or was included on a filed plat" before the zoning ordinance began, "provided the property owner cannot replat adjacent abutting land to meet these new lot restrictions and yard regulations are complied with."
Duplexes are allowed in more than R-2. R-3F allows "All uses allowed in section 31-231" (Sec. 31-255.1), and R-3A allows "Any use permitted in the R-1 or R-2 districts" (Sec. 31-256.1). A lot used for a house or duplex still follows the R-1 or R-2 lot rules in R-3 (Sec. 31-248(c)).
Getting R-2 zoning means a rezoning under Sec. 31-39, with a $500 application fee in FY 2027. Council records show the City starting such changes itself, such as Case Z26-03, which moved six lots on West Jasper Drive from B-3 to R-2 on March 24, 2026. The zoning districts page explains the steps.
Design Rules for Houses and Duplexes
Article VI, Division 1 applies to "all new residential single-family and two-family developments, including single family homes, patio homes, garden homes, townhomes, and duplexes." Additions to existing homes, accessory buildings under 200 square feet and manufactured homes in an R-MP park are exempt (Sec. 31-901).
| Building | Elements required | Entry or porch option |
|---|---|---|
| Single-family house | At least 5 of 15 elements | Covered entry of 40 sq ft, or covered porch of 80 sq ft |
| Two-family building (duplex) | At least 4 of 15 elements | Covered entry of 20 sq ft per home, or covered porch of 60 sq ft per home |
Source: Killeen Code of Ordinances, Sec. 31-904, Supplement 38 Update 1.
The 15 elements in Sec. 31-904 include enhanced windows, two or more decorative features such as columns or coach lights, two roof types, a side or rear entry garage, a garage wall recessed 5 feet, three front wall planes offset 12 inches, a covered entry or porch, an enclosed front patio, enhanced front doors, an eyebrow roof, windows or hardware on garage doors, two 8-foot garage doors instead of one 16-foot door, and a ribbon driveway where there is no garage. A covered porch counts as two elements. An applicant submits "An architectural elements checklist" with each permit.
Two more rules apply. Sec. 31-902 says "Two-family homes of the same elevation shall not be placed within two (2) lots on the same side of the street, or directly across the street from one another," and mirrored elevations count as the same. Sec. 31-903 says a garage door facing the street may take up no more than 50 percent of the front elevation, or the walls beside it may not stick out past the rest of the front.
Permits, Fees and North Killeen
The FY 2027 Fee Schedule, in effect from October 1, 2026, lists "New and Additions: Single Family, Duplex, and Townhouse" at $0.20 per square foot with a $200 minimum, plus plan review at $0.05 per square foot when two or more permit types are requested at the same time, and a $10 tech fee. The schedule says this fee "includes permits for structure, electrical, mechanical, plumbing, and required inspections." Fences, accessory structures, lawn irrigation and pools need their own permits. Parkland fees per home and water and sewer impact fees are covered on the plats, permits and fees page.
The North Killeen Revitalization Program, amended by the City Council on January 7, 2025, offers incentives in the older north part of the city. For new construction or rehabilitation that spends at least $2,000, once the City approves an incentive application, the City may waive "All building permit related fees (including plans review and inspections)," plat application fees, Zoning Board of Adjustment fees, and parkland dedication and development fees. The Executive Director of Development Services may reduce or eliminate off-street parking there "if it is deemed that doing so will advance the City's revitalization efforts." Under Sec. 26-10(b), a building permit for "a single-family or two-family dwelling and related accessory structures" in the area needs no plat when the lot boundaries have not changed and the City needs no right-of-way.
Best For
- ✓ An R-2 lot of 7,000 sq ft and 60 feet wide, where a duplex is allowed by right with four parking spaces.
- ✓ An A-R1 or SR-2 owner who wants a guest house for family, up to a quarter of the house size.
- ✓ A North Killeen lot where permit and parkland fees can be waived.
Usually Fails When
- ✕ The plan rents a guest house or a second unit on an R-1 lot.
- ✕ The duplex design meets fewer than four of the 15 architectural elements.
- ✕ The lot cannot fit four parking spaces outside the 20-foot front yard.
What To Verify Before Spending Money
- → The district of the lot, and whether R-2 zoning is in place or needs a rezoning.
- → Whether the City has adopted an ADU or tiny home overlay since April 2026.
- → Whether the lot is inside the North Killeen Revitalization Area and eligible for waivers.
Where to Go Next
Related on VanPlex: the Killeen overview, ADUs in Texas, and building codes from duplex to fourplex.
Frequently Asked Questions
Can I build an ADU in my backyard in Killeen?
What is a guest house under Killeen zoning?
Can I rent out a guest house in Killeen?
What size lot do I need for a duplex in Killeen?
Which Killeen districts allow a duplex?
How many parking spaces does a Killeen duplex need?
What design rules apply to a new duplex in Killeen?
How much is a building permit for a new duplex in Killeen?
Can an accessory building in Killeen be two stories?
Are there fee waivers for building a duplex in North Killeen?
Official sources (checked October 2026)
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