Which Austin HOME or ADU Path Fits Your Property?

The words “ADU,” “HOME” and “small lot” are sometimes used as if they describe the same approval. They do not. Choosing the route early helps the survey, concept, permit documents and builder quote describe one project.

Begin with the homes that exist and the homes you want

Draw every current and proposed dwelling. State whether each is detached, attached or inside an existing structure. Mark any building that would be removed and whether a lot division is part of the idea.

Austin’s ADU guidance describes a separate dwelling on the same property as a single-family house. The unit has its own living space and includes a full bathroom plus a sink or dishwasher outside the bathroom. The City’s HOME amendments also create paths for some two-unit and three-unit projects and for one home on a qualifying small lot.

Do not start with a sales label such as “casita” or “tiny home.” Start with the proposed use, dwelling count and physical arrangement.

Use the ADU path when it matches the project

Austin’s Additional Dwelling Units guidance remains a public starting point. It outlines a path that includes checking public and private rules, obtaining a unique address, submitting plans, completing review, activating permits, building, passing inspections and receiving final occupancy approval.

That sequence does not prove that an ADU fits one property. It tells the owner which tasks belong in the project. The feasibility guide helps connect those tasks to the parcel, trees, drainage, access and utilities.

Understand HOME Phase 1

Austin says HOME Phase 1 allows up to three housing units on qualifying SF-1, SF-2 and SF-3 property. The units can use arrangements permitted by the applicable standards.

For two-unit and three-unit residential uses, the City currently lists a maximum building coverage of 40% and maximum impervious cover of 45%. Building coverage is the share of the lot occupied by buildings. Impervious cover also includes roofs, paving and other surfaces that do not absorb rain.

These percentages do not replace the rest of the analysis. The design still has to address setbacks, height, trees, drainage, utilities, technical code and any property-specific controls. “Up to three units” should never be turned into “three units are approved here.”

The City’s application data through July 6, 2026 reports 829 HOME applications reviewed, 657 approved and 1,309 new units approved. Those figures show that the pathway is being used. They are not approval odds for a new application, because properties, designs and review issues differ.

Understand HOME Phase 2

HOME Phase 2 created a small-lot single-family route for lots from 1,800 square feet to less than 5,750 square feet. It is a path for one home on the small lot, not a statement that every small lot can take an ADU.

An existing qualifying lot may follow a building-permit route. Creating a new lot can involve subdivision, legal, access, drainage and utility work before the house is ready for building review. If the project depends on dividing land, price those tasks separately from the dwelling.

Treat the address as a design task

Austin requires a unique address or building number for every new dwelling before the residential permit application. The HOME page also states that each dwelling in a two-unit or three-unit use needs a unique address.

Assign responsibility for the address request. Use the approved address consistently on plans, utility requests, emergency-access records and later project documents. Delaying the task can create mismatched paperwork and utility assumptions.

Test the housing path against the site

Once the route is selected, put it on a base plan. Show:

• property boundaries and existing buildings;
• the proposed dwelling or dwellings;
• roofs, paving and other hard surfaces;
• easements and setbacks;
• protected trees and likely root areas;
• drainage, flood and creek conditions;
• resident, emergency and construction access; and
• water, wastewater and electric routes.

Austin’s rules can make a use possible while the physical site still forces a smaller or different design. The opposite can also happen: a yard can look open while the current rules, easements or services make the first concept unsuitable.

Keep private restrictions in a separate column

City permission and private restrictions are different questions. Gather the deed, recorded covenants and relevant association documents. Seek legal advice when their meaning or enforceability matters.

Do not use an HOA statement as a substitute for the City’s classification. Do not use a City permit as proof that every private obligation has been resolved. Record the two answers separately.

Put the selected path in every quote

Every proposal should state:

• the current and proposed number of dwellings;
• whether each unit is detached, attached or internal;
• the Austin path and dated source being assumed;
• the planned floor area and site position;
• the address and utility assumptions;
• design, permit and specialist responsibilities; and
• any standards still waiting for confirmation.

If two bidders assume different housing paths, their totals are not comparable. Use the cost guide to align the whole project and the builder comparison guide to find missing work.

Use current City review timing carefully

Starting July 1, 2026, Austin Residential Plan Review lists 10 business days for new construction and additions. The clock has stated starting conditions, and other review groups, corrections, applicant responses and utility work can extend the elapsed time.

Treat the figure as one review target, not a promise for design, permits or the complete build. Put every dependency on the project timeline.