Usually this means splitting one lot into two, which is a platting question before it is a building question. Whether it works comes down to the minimum lot size on your block, how much street frontage each new lot would get, and what access it can legally take.
If you want each home on its own lot, you are creating a second lot, and that takes a plat or a replat. The lot has to clear the minimum size on both halves, and each half needs legal access.
Start with the alley. If the property abuts an alley that the City or a homeowners association maintains, the new lots must take access from it unless the Director finds the alley unusable (section 42-188), and corner lots follow a separate rule. Without a usable alley, inside the city, a lot 44 feet wide or more can take its own driveway from the street. Between 33 and 44 feet, one driveway up to 12 feet wide is allowed only on property of 15,000 square feet or less (section 42-188); otherwise the lots share access through a flag staff, a shared driveway or an access easement. Under 33 feet the lots share access too, with one exception for older narrow lots: property platted before September 27, 2023 that is too narrow to split into two 33 foot lots can still give each half one driveway up to 12 feet wide, if it has no usable side or rear access, its garage sits at least 20 feet back, it is more than 1,400 feet of walking distance from a school entrance, and it is outside a Complete Community (section 42-188.5). Those are city rules, and the ETJ does not offer shared driveways at all.
Inside the city a plat can include lots smaller than 3,500 square feet in two ways. One is to provide compensating open space (section 42-182). The other is the standard in section 42-184, which allows lots down to an average of 1,400 square feet when more than 60 percent of each small lot stays uncovered by buildings (75 percent for a replat of a corner lot), each has at least 150 square feet of permeable area, and the whole plat is capped at 27 homes per acre, or 35 per acre when every lot takes access from the rear or side through an alley, flag staff, shared driveway or access easement. Section 42-184 applies only inside the city.
Under section 42-187, lots narrower than 44 feet that take access by flag staff share that staff, and the plat must carry a note saying the access is shared. Both lots count as flag lots, and the note stays on the recorded plat for every future buyer to read.
Every read queries the City of Houston's own GIS layers rather than a generic parcel database, and it separates what it confirmed from what it could not. Where a layer does not answer, the report says so instead of filling the gap with a default. A confident wrong answer about whether your lot can be split is worse than no answer, because you would act on it.
Private deed restrictions are recorded with the county. We do not read them, and a title report is how you confirm them.