FIELD NOTES / ARCHITECTURE & PLACE
City of Austin Land Development Code: how to read what a lot allows before you buy or build
The City of Austin Land Development Code decides what a lot allows before any house is drawn, and its rules are public before you make an offer. The code caps impervious cover at 40% on SF-1 lots and 45% on SF-2 and SF-3 lots and regulates every tree 19 inches or more in diameter, and the City bills a monthly drainage charge computed from each parcel's hard surfaces at $0.00593 per square foot in fiscal 2026. This guide walks through cover and zoning, slope and drainage, trees, easements and floodplain, water, and the records that show how a house, or a future house, sits on its land.
By David Eimer · Austin Journal · 11 minute read · Published
The numbers
- Maximum impervious cover, SF-2 and SF-3 lots
- 45%As of City of Austin residential standards briefing, October 26, 2023
40% in SF-1; building cover 35% in SF-1 and 40% in SF-2 and SF-3; 35-foot height limit. The April 2024 HOME Phase 2 review sheet lists the same caps.
Source: City of Austin ↗
- Regulated tree thresholds on residential property
- 19 inches protected · 24 inches heritageAs of City Arborist rules, checked September 26, 2026
Diameter measured 4.5 feet above the ground; heritage status applies to listed species, including all oaks, pecan, cedar elm and bald cypress.
- Drainage charge base rate
- $0.00593 per sq ft of impervious cover per monthAs of Fiscal 2026
Multiplied by an adjustment factor of (1.5425 × percent impervious cover) + 0.1933.
- Smallest lot for one home in SF-1, SF-2 and SF-3
- 1,800 sq ftAs of HOME Phase 2, adopted May 16, 2024
The standard residential minimum stays 5,750 sq ft; up to three units are allowed on a standard lot under HOME Phase 1, adopted December 7, 2023.
- Outdoor watering, Conservation Stage
- 1 day a week automatic · 2 days hose-end or dripAs of In effect since September 2025
Midnight to 10 a.m. or 7 p.m. to midnight, on days assigned by address; hand watering and tree bubblers any time.
Source: Austin Water ↗
- Median sale price and months of inventory, Austin metro
- $412,000 · 5.1 monthsAs of August 2026
Homes, not land; Unlock MLS's release does not break out lot sales. City of Austin $560,000 and 4.6 months.
Source: Unlock MLS ↗
City of Austin Land Development Code: what does the lot decide before the house does?
The City of Austin Land Development Code sets the limits a building has to live inside, whether the lot is vacant or the yard under an existing house. The code's zoning chapter fixes how much of a lot can be paved or roofed, its environmental chapter regulates trees over 19 inches and creek setbacks, the lot's own slope and drainage decide where water goes in a Central Texas storm, and easements and floodplain lines rule some ground out entirely. A porch or a wall of glass is the visible result of those decisions, so the visit should start where the building meets the ground.
Land for sale in Austin is listed through the same MLS as houses, so see current listings for what is on the market; the figures below are for houses, not raw land, because Unlock MLS's monthly release does not break out land sales. For August 2026 it reports a $412,000 median sale price across the Austin metro, $560,000 in the City of Austin and $489,000 in Travis County, with 5.1 months of inventory metro-wide and 4.6 in the city. Those medians mix lot sizes and neighborhoods and say nothing about any single parcel; the September 2026 market post explains what they do and do not cover.
What follows is the order a working agent would use: cover and zoning first, because they cap what can be built; then water, trees, easements and floodplain, because they decide where; then the visit itself. The property research desk lists the public tools each step uses.
Sources: Unlock MLS ↗ · City of Austin Development Services ↗
How much of an Austin lot can be covered? Impervious cover, building cover and zoning
Impervious cover is the first number to look up for any Austin lot, because it caps roofs, driveways and patios together. The City's Watershed Protection Department defines it as “any surface that prevents the infiltration of water into the ground,” and its drainage charge counts “Rooftops, Patios, Driveways, paved and unpaved, Parking lots, paved and unpaved, Other surfaces that do not absorb rainfall.” For existing single-family lots the limit is set by zoning: the City's October 2023 briefing on residential standards lists a maximum of 40% impervious cover and 35% building cover in SF-1, and 45% impervious cover and 40% building cover in SF-2 and SF-3, with a 35-foot height limit in each.
Site development standards for a single home on an Austin single-family lot
| Standard | SF-1 lot | SF-2 and SF-3 lot | Small lot, one unit (HOME Phase 2) |
|---|---|---|---|
| Minimum lot size | 10,000 sq ft | 5,750 sq ft | At least 1,800 sq ft, under 5,750 sq ft |
| Minimum lot width | 60 ft | 50 ft | 20 to 30 ft (30 ft with an individual driveway) |
| Front setback | 25 ft | 25 ft | 15 ft (5 ft on a flag lot) |
| Side setback | 5 ft | 5 ft | 5 ft |
| Rear setback | 10 ft | 10 ft | 5 ft |
| Impervious cover, maximum | 40% | 45% | 45% |
| Building cover, maximum | 35% | 40% | Not applied |
| Height, maximum | 35 ft | 35 ft | 35 ft |
| Floor-area ratio inside the Residential Design and Compatibility boundary | Greater of 2,300 sq ft or 0.4 | Greater of 2,300 sq ft or 0.4 | Greater of 1,450 sq ft or 0.55 |
The HOME amendments changed what can sit inside those caps without raising them. HOME Phase 1, adopted December 7, 2023, allows up to three housing units on an SF-1, SF-2 or SF-3 lot; HOME Phase 2, adopted May 16, 2024, created a “small lot single-family residential use” for one unit on lots “of at least 1,800 square feet but less than 5,750 square feet,” the standard residential minimum. The City's April 2024 staff review sheet for Phase 2 kept the 45% impervious cover maximum for SF-2 and SF-3, raised SF-1 small lots from 40% to 45%, capped front-yard impervious cover at 50% except on flag lots, and carried a floor-area ratio of 0.4 inside the Residential Design and Compatibility boundary.
Two cautions. Zoning is only one of two impervious cover systems: the Watershed Protection Department's analysis notes that outside the Urban watersheds, development other than existing single-family lots is governed by “the lower (i.e., more protective)” of the zoning and watershed limits, and that a stated maximum “may not be attainable” because of trees, waterways and steep slopes. And the number that matters for a lot you are buying is what is already built: the City's Property Profile map carries an “Impervious Cover 2023” layer, and its drainage charge lookup shows the square footage the City bills. The zoning and deed restrictions guide covers the district lookup and the private covenants that can be stricter than the code.
Sources: City of Austin Watershed Protection ↗ · City of Austin ↗ · City of Austin Development Services ↗
Where does the water go? Slope, drainage and the Austin drainage charge
Drainage on an Austin lot is a private matter until it reaches the street, and the City bills every parcel for its share of the runoff. The Watershed Protection Department calculates the monthly drainage charge as impervious cover in square feet, times a base rate of $0.00593 per square foot for fiscal 2026, times an adjustment factor of (1.5425 × the percent of the lot that is impervious) + 0.1933. The City's own example is an $8.04 annual increase for a home with 3,100 square feet of impervious cover on a 37% covered lot under the 2025-26 rate change; the table shows what the formula produces for a few parcel shapes.
What the City of Austin's drainage charge formula produces for four parcel shapes
| Impervious cover | Lot size | Share of lot covered | Adjustment factor | Monthly charge |
|---|---|---|---|---|
| 2,000 sq ft | 5,750 sq ft | 34.8% | 0.730 | $8.66 |
| 3,100 sq ft | 8,400 sq ft | 36.9% | 0.763 | $14.02 |
| 4,500 sq ft | 10,000 sq ft | 45.0% | 0.887 | $23.68 |
| 6,000 sq ft | 20,000 sq ft | 30.0% | 0.656 | $23.34 |
The formula rewards a lot that keeps more ground open, and it is a clue to how the City thinks about runoff. Its local flooding program notes that “Storm drain systems may be undersized in neighborhoods that were built before drainage regulations took effect in the early 1980s,” and that annexed neighborhoods “may also have inadequate drainage infrastructure,” so a 1960s lot in a low spot can flood from the street even when its own yard drains well. Property Profile's layers include contours, a slope layer for grades over 15 percent, the Erosion Hazard Zone review buffer and public and private drainage pipes, inlets and ponds, which together show where water is supposed to go.
On the visit, the useful check is after rain. A buyer's inspector must report as Deficient “drainage around the foundation that is not performing” and deficient grade levels, gutters and downspouts, but the TREC standards say the inspector is not required to “determine area hydrology or the presence of underground water” or the performance of underground drainage. The seller's answers cover the rest: TREC's Form 55-1 asks whether the seller is aware of “Improper Drainage,” “Landfill, Settling, Soil Movement, Fault Lines,” and “Water Damage Not Due to a Flood Event.” Where those three sources disagree with what the yard looks like, the yard is usually right.
Sources: City of Austin Watershed Protection ↗ · City of Austin ↗ · Texas Real Estate Commission ↗
Which trees on an Austin lot are protected, and what does that do to a site plan?
Trees on an Austin lot are regulated by trunk size, and the thresholds decide how much of the ground can be built on. The City Arborist's rules: a Protected tree has “a diameter of 19 inches or more, at a point measured 4.5 feet above the ground,” and every species qualifies; a Heritage tree is 24 inches or more and one of a listed set of species, including all oaks, pecan, bald cypress, cedar elm, American elm, Texas ash, bigtooth maple, Texas madrone and two walnuts; at 30 inches and larger, proposed variances go through a public process.
How the City of Austin classifies trees on residential property
| Trunk diameter at 4.5 feet | Classification | What it means for the lot |
|---|---|---|
| Under 19 inches | Not regulated on residential property | No Tree Ordinance Review Application to remove or work near it; other permits may still apply |
| 19 inches and larger | Protected tree, all species | Permit required to remove, to prune 25% or more of the canopy, or to disturb the critical root zone |
| 24 inches and larger, listed species | Heritage tree: Texas ash, bald cypress, American elm, cedar elm, Texas madrone, bigtooth maple, all oaks, pecan, Arizona walnut, Eastern black walnut | Removal prohibited except as provided in City Code § 25-8-641; a variance is required for removal or impacts beyond code requirements |
| 30 inches and larger heritage trees | Heritage tree, largest tier | Proposed variances go through a public process |
The trunk is only part of the footprint. The City's residential tree page explains that a Tree Ordinance Review Application is needed to remove a regulated tree, to prune 25% or more of its canopy, or to “start an activity that may impact a tree or cause a disturbance to the critical root zone.” Inside that zone, the quarter closest to the trunk allows no impacts, the inner half allows no cut or fill greater than 4 inches, and half of the full zone must be preserved without impact. On a 50-foot-wide SF-3 lot, one heritage oak near the center can decide where a driveway, addition or pool cannot go before any drawing is made. The tree guide for buyers with renovation plans walks through measuring and the permit steps.
Measure before you fall for the canopy. The City's method is a tape around the trunk at 4.5 feet, divided by 3.14; for a multi-stemmed tree, take the largest stem and add half of each additional stem. The City's own example is a cedar elm with 18-inch and 16-inch stems, which counts as 26 inches and is therefore a heritage tree.
What easements, floodplain and setbacks limit where a house can sit?
Easements and floodplain lines on an Austin lot remove ground from the buildable area before zoning setbacks are applied. Drainage easements, the Watershed Protection Department explains, “allow us to access and use a portion of private property for the purposes of managing stormwater runoff and reducing flood risk,” and “Permanent structures are not allowed in drainage easements. This includes buildings, sheds, fences, pools, etc.” Owners are asked not to plant trees or intensive landscaping in them and typically maintain the surface: mowing, keeping the area clear of debris and ensuring nothing blocks the flow of water.
Find them in the plat and deed records and on Property Profile's Easement Polygons layer, then read the seller's disclosure. Form 55-1 asks about “Unplatted Easements” in Section 4, about conservation easements and a private road the seller must maintain in Section 9, and in Section 6 whether the property is wholly or partly in a 100-year floodplain, 500-year floodplain, floodway, flood pool or reservoir. FloodPro, the City's map tool, is where to “find out if your Austin property is in a floodplain” and to look up elevation certificates; the flood map guide explains what each zone means for insurance and for building.
Then the setbacks. Under the standards the City's HOME Phase 2 review sheet lists as existing for a standard single-family lot, a house sits at least 25 feet from the front line, 15 feet from a side street, 5 feet from an interior side line and 10 feet from the rear; the small-lot use reduces the front to 15 feet and the rear to 5 feet. Subtract the setbacks, the easements, the floodplain, the critical root zones and the impervious cover cap from the lot's recorded size on TCAD, and what is left is the ground a house can actually use.
Sources: City of Austin Watershed Protection ↗ · City of Austin ↗ · Texas Real Estate Commission ↗ · Travis Central Appraisal District ↗
How much water will an Austin yard need, and what does the City pay to reduce it?
An Austin yard is watered on a schedule, so the landscape you buy should be one that can live on it. Under the Conservation Stage restrictions Austin returned to in September 2025, automatic irrigation systems may run one day a week and hose-end sprinklers or drip irrigation two days a week, only between midnight and 10 a.m. or 7 p.m. and midnight, on days assigned by address; hand watering and tree bubblers are allowed at any time. Austin Water says watering once a week instead of two or three times could save an average household “7,000 to 14,000 gallons every month.”
The plant choice sets the demand. Austin Water's WaterWise guide notes that turf “typically needs 1 inch of water weekly in summer” while “mature native beds may need only ½ to ¾ inch every other week,” and that converting 500 square feet of turf “could save up to 930 gallons per month.” The City pays for that conversion and for the hardware around it.
Austin Water residential rebates for the yard
| Rebate | Amount |
|---|---|
| WaterWise Landscape (turfgrass to native and adapted plant beds) | Up to $1,750 |
| WaterWise Rainscape (features that keep rainwater on the land) | Up to $500 per property |
| Rainwater harvesting | Up to $5,000 |
| Irrigation upgrade | Up to $1,000 |
| Compost, mulch and core aeration | Up to $120 |
| Pressure regulating valve | Up to $150 |
| Watering timer | 50% of the before-tax price, up to $40, for up to two timers |
For a buyer, the practical reading is the irrigation system on the disclosure. Form 55-1 lists an “Automatic Lawn Sprinkler System” among the items the seller marks present or not, and TREC's inspection form treats landscape irrigation as an optional system, inspected only if the buyer asks for it. A lot that is mostly turf on an automatic system will be watered one day a week; a lot with mature native beds and shade from regulated trees asks less of the schedule and of the water bill.
Sources: Austin Water ↗ · City of Austin Watershed Protection and Austin Water ↗ · Texas Real Estate Commission ↗
How do you read a home's relationship to its land on the visit?
Reading how an Austin house sits on its land starts at the threshold, before the floor plan. Stand where the building meets the ground: a porch, a small court or a covered step tells you how the house invites people in and whether that space is usable in July at four in the afternoon. Then look for the ordinary view, the window at the kitchen sink and the one you would see first each morning, and ask what changes when the cedar elms drop their leaves.
Visit at more than one time of day if you can, and stand in the outdoor spaces you expect to use. Ask how the owners use them through the year, and keep their account separate from what you can verify: the slope on the contour layer, the drainage charge on the utility bill, the tree diameters at 4.5 feet, the easement on the plat, the disclosure's answers about drainage and soil movement. An appealing landscape is not evidence that any of those has been resolved, and the buyer's guide to what listing photos cannot show covers the same discipline indoors.
TCAD's property search gives the lot's recorded size and the improvements on it, searchable by owner name, address or account number; the City's Property Profile gives the layers above; FloodPro gives the water. If you want them read together for one parcel, with the cover cap, the trees and the easements drawn against the lot before you decide what could be built or kept, bring the address to David and the site can be worked through on paper before the second visit.
Sources: Travis Central Appraisal District ↗ · City of Austin Development Services ↗ · City of Austin Watershed Protection ↗
Common questions
How much of a lot can you build on in Austin?
On a single-family lot the City of Austin caps impervious cover, meaning roofs, driveways, patios and any surface that does not absorb rain, at 40% in SF-1 zoning and 45% in SF-2 and SF-3, with building cover limited to 35% and 40% respectively and a 35-foot height limit. Inside the Residential Design and Compatibility boundary, floor area is also capped at the greater of 2,300 square feet or 0.4 times the lot. Trees over 19 inches, easements, floodplain and setbacks can reduce the usable area further.
What is the minimum lot size in Austin?
The standard residential minimum is 5,750 square feet in SF-2 and SF-3 zoning and 10,000 square feet in SF-1, per the City's residential standards briefing. Since HOME Phase 2 was adopted on May 16, 2024, a small lot single-family residential use allows one home on a lot of at least 1,800 square feet but less than 5,750 square feet in SF-1, SF-2 and SF-3, usually through a subdivision or residential infill application.
Can I remove a tree on my property in Austin?
Trees under 19 inches in diameter, measured 4.5 feet above the ground, are not regulated on residential property. At 19 inches and larger a tree is Protected and a Tree Ordinance Review Application is required to remove it, prune 25% or more of its canopy, or disturb its critical root zone. At 24 inches and larger, oaks, pecans, cedar and American elms, bald cypress, Texas ash, bigtooth maple, Texas madrone and two walnut species are Heritage trees, and removal is prohibited except as provided in City Code § 25-8-641.
How is the Austin drainage charge calculated?
The City of Austin bills a monthly drainage charge equal to a parcel's impervious cover in square feet, times a base rate of $0.00593 per square foot for fiscal 2026, times an adjustment factor of (1.5425 × the percent of the lot that is impervious) + 0.1933. A lot with 3,100 square feet of impervious cover covering 37% of its area is the City's own example. Owners can check the square footage the City uses on its Find My Drainage Charge map and ask for a review through Austin Energy's customer care line.
What should I check before buying land for sale in Austin?
Five public records, in this order: the parcel's zoning district and impervious cover cap (40% in SF-1, 45% in SF-2 and SF-3), the City's Property Profile layers for easements, floodplain, slope and existing impervious cover, the trunk size of every tree near the building area (19 inches and up is regulated, 24 inches and up may be heritage), the plat and deed for easements, and FloodPro for the floodplain. Lots and acreage are listed through the same MLS as houses, and Unlock MLS does not publish separate land statistics, so price a lot against what the code lets you build on it.
Can you build in a drainage easement in Austin?
No permanent structures. The Watershed Protection Department states that buildings, sheds, fences and pools are not allowed in drainage easements, and asks owners not to plant trees or intensive landscaping that could block the flow of water. Some easement documents permit limited improvements, and an owner can request a license agreement where they do not. Easements appear in the plat and deed records and on the City's Property Profile map, and the seller's disclosure asks about unplatted easements.
Take this to your next conversation
- Open Property Profile for the parcel and note zoning, the 2023 impervious cover layer, easement polygons, floodplain and the slope layer before the first visit.
- Measure every trunk near the likely building area at 4.5 feet: anything at 19 inches or more shapes the site plan, and 24-inch oaks, elms and pecans are heritage trees.
- Walk the lot after rain and compare what you see with the inspector's grading-and-drainage findings and the seller's answers on drainage and soil movement in Form 55-1.
Sources and review date
Sources checked . Planning suggestions are editorial guidance; current property facts and requirements need an address-specific check.
- Unlock MLS: August 2026 Central Texas Housing Report, released September 15, 2026 ↗
- City of Austin Watershed Protection: Analysis of proposed impervious cover entitlements, November 29, 2017 (PDF) ↗
- City of Austin Watershed Protection: Drainage charge ↗
- City of Austin: Changes to residential uses and standards (including HOME amendments), joint Planning Commission and City Council briefing, October 26, 2023 (PDF) ↗
- City of Austin: Ordinance amendment review sheet C20-2023-024, HOME Phase 2, April 23, 2024 (PDF) ↗
- City of Austin Development Services: HOME Amendments ↗
- City of Austin Development Services: Property Profile overview ↗
- City of Austin: Property Profile layers, June 2026 (PDF) ↗
- City of Austin Watershed Protection: Local flooding projects ↗
- City of Austin Watershed Protection: Drainage easements ↗
- Texas Real Estate Commission: TREC Rules, 22 TAC §§ 535.227 and 535.228, Standards of Practice for inspectors ↗
- Texas Real Estate Commission: Seller's Disclosure Notice, Form 55-1 (PDF) ↗
- Texas Real Estate Commission: Property Inspection Report, Form REI 7-6 (PDF) ↗
- City of Austin Development Services: City Arborist, tree reviews and permitting ↗
- City of Austin Development Services: Trees on residential property ↗
- City of Austin Watershed Protection: View floodplain maps and storm drain infrastructure (FloodPro) ↗
- Austin Water: Find your watering day (current water restrictions) ↗
- Austin Water: Austin returns to Conservation Stage watering restrictions ↗
- Austin Water: WaterWise Landscaping rebate guide ↗
- City of Austin Watershed Protection and Austin Water: Rebates, free stuff and grants ↗
- Travis Central Appraisal District: Property Search ↗