As of October 2026, an Ann Arbor lot zoned R1 holds the same rights it held before City Council adopted the Comprehensive Land Use Plan 2050. Council approved that plan 11-0 on March 16, 2026, by Resolution 26-0367, after the Planning Commission adopted it on February 18. The plan describes neighborhoods with duplexes and triplexes as primary uses. The zoning code that decides what you can build on a lot today still treats R1 as single-family.
A buyer comparing Ann Arbor with other Southeast Michigan markets may hear "the city upzoned" and assume a single-family house now comes with room for more units. In practice, any future upside on an R1 lot depends on a code rewrite that hasn't started yet, follows a set order, and has a multi-year estimate attached.
The plan says it isn't law
The clearest source on this is the plan itself. In its section on what a comprehensive plan can and cannot do, the adopted Ann Arbor Comprehensive Plan says it "is not a law, and its adoption does not change any laws, regulations, or requirements" that apply to physical development.
The plan's Residential future land use category does point toward change. It calls for low-rise buildings of about three stories, duplexes and triplexes permitted as primary uses, and new residential districts with adjusted dimensional standards, such as maximum building footprints and setback and lot-size changes, to make room for additional housing types. Those are instructions to the people who will write the next zoning code. They don't give any rights to the owner of a particular parcel.
The plan also doesn't convert every R1 lot into one future category. Existing residential districts are divided between Residential and Transition areas based on factors that include transit proximity, closeness to hubs, and historic districts. Two R1 houses on different streets could end up under different rules once the new map is drawn.
The sequence as of October 12, 2026
The steps that turn the plan into enforceable zoning are now on public record, and the dates are specific.
| Date | Step | What it changed for an R1 lot |
|---|---|---|
| February 18, 2026 | Planning Commission adopts the plan | Nothing in the code |
| March 16, 2026 | City Council adopts the plan 11-0 | Nothing in the code |
| April 14, 2026 | Planning Commission work session on implementation; Hub districts go first | Puts residential rules later in the queue |
| August 11, 2026 | Proposals due for the code rewrite contract | Nothing in the code |
| October 5, 2026 | Council approves a $786,499 agreement with Stantec | Starts the work, doesn't change the rules |
| November 2026 | Anticipated start of the rewrite | Drafting begins |
Council's October 5 approval of the Stantec agreement, recorded as R-26-392, covers both the Unified Development Code rewrite and a review of the city's development review process. The city's request for proposals estimated 24 to 36 months for the code rewrite from a November 2026 start, and four to six months for the process-review report. Counted from November 2026, that estimate ends somewhere between late 2028 and late 2029. A new code and zoning map would still need public review and adoption votes after that.
The scope is broad. The RFP calls for new Hub, Transition, and Residential districts that would replace most or all of the existing residential, mixed-use, and non-residential districts, with the PL Public Land district as the notable exception. The Residential district is to allow "no less than triplexes" along with neighborhood-oriented commercial uses. On parking, the city plans to keep its existing policy of no minimums and to consider maximums, so this is not a new change.
Neighborhood rules come after the hubs
The order matters more than the overall estimate. MLive reported that at the April 14 work session, planning commissioners chose to start with high-density Hub districts. New zoning for transition and low-rise residential areas could follow after that, and the first Hub step alone was expected to take several months of zoning work. Lisa Disch, City Council's liaison to the Planning Commission, told MLive the goal was to "go to the most bang for the buck and get something on the map that will give us meaningful density."
The future land use map shows nine potential hubs. They include an expanded downtown, the Briarwood Mall area around State Street and Eisenhower Parkway, and locations on Plymouth Road, Washtenaw Avenue, Stadium Boulevard, and Maple Road. The Ann Arbor Observer also lists South University among the nine. City planners told MLive that about half of the roughly 1,600 properties in those areas already have TC1 transit corridor zoning or D1 or D2 downtown zoning.
So the first phase works mostly where high-density zoning already exists or sits right next door. Interior R1 blocks come later, under standards that haven't been drafted.
Where density is going up now
Ann Arbor is adding housing in 2026, but under zoning the city adopted years before the new plan. According to the city, the TC1 transit corridor district dates to 2021, with earlier rezonings along South State and East and West Eisenhower and along West Stadium and North Maple.
Two current projects show what that looks like:
- 2424 E. Stadium Blvd. Council approved a development agreement on October 5, 2026, for 307 apartments from Stadium Investors 1 LLC, a Beztak affiliate, next to Trader Joe's. The Planning Commission had approved the site plan in July, MLive reported.
- Arbor South, at 2845 S. State and nearby Eisenhower parcels. MLive reported in February 2026 that Council approved its development agreement and brownfield plan on an 8-2 vote. The city's project page describes a phased, 15-building project with 229 affordable and 839 market-rate apartments. MLive's count was 14 buildings, a difference that likely reflects different versions of the plan.
Neither project relies on the 2050 plan's new districts, because those districts don't exist yet. In 2026, Ann Arbor's added density sits along corridors that were rezoned in the early 2020s. It hasn't reached single-family blocks.
What an R1 lot allows today
The rules that apply now are in the current Unified Development Code, the eleventh edition, effective August 10, 2025. It describes R1A through R1E as single-family districts meant to provide "an environment of detached single-family dwellings." Two-family dwellings belong to the separate R2A and R2B districts.
The added unit the code does allow on an R1 lot is an accessory dwelling unit, permitted when the lot's main use is one single-family house. The ADU can be up to 600 square feet on lots under 7,200 square feet, or up to 800 square feet on larger lots. In either case it can't be larger than the ground-floor area of the main house. The city's 2025 and 2026 code amendments dealt with parking, height exceptions, stormwater review, and other procedural items. They didn't change the ADU standard or allow two-family homes in R1.
For a buyer, that means the only entitlement you can verify on an R1 parcel today is one house plus one ADU within those size limits. Anything beyond that depends on a code that hasn't been written.
The market gives buyers time to look closely
The current market is relevant because it affects whether a buyer feels pressure to pay for upside before the rules exist. The most recent area report from the Ann Arbor Area Chapter, covering August 2026 and current as of September 9, shows a looser market across Washtenaw County. These are county figures, not City of Ann Arbor figures.
| Washtenaw County single-family, August 2026 | Value | Change from August 2025 |
|---|---|---|
| Median sale price | $475,000 | +2.2% |
| Average sale price | $532,634 | −6.5% |
| Closed sales | 239 | −4.8% |
| Days on market until sale | 30 | +7.1% |
| Homes for sale | 739 | +21.5% |
| Months supply | 3.3 | +22.2% |
| Percent of list price received | 99.4% | −0.2% |
The same report shows single-family pending sales at 144 in August 2026, compared with 251 a year earlier. One month isn't a trend, and that figure should be checked against the September report before anyone reads much into it. Still, more inventory, more months of supply, and homes selling slightly below list all point toward buyers having more choice than they did a year ago.
That is the context for any talk of "triplex potential." The plan is real, the contract is signed, and the city's own estimate puts the rewrite in late 2028 at the earliest. In the meantime, buyers in August 2026 faced more options across the county and more time to decide. No study has yet measured whether the adopted plan has changed home prices in the city. Predictions made before adoption differed, and they remain predictions.
Questions to answer before you price in zoning upside
These are the questions that show what you are actually buying on a given Ann Arbor parcel:
- What is the parcel's current zoning district under the August 2025 UDC?
- Which future land use category does the adopted plan assign to that location: Residential, Transition, or Hub?
- Is the parcel inside a historic district, which the plan lists as a factor in how areas are categorized?
- Is it in or near one of the nine Hub areas, where rezoning work begins first?
- Does the lot meet the 7,200-square-foot threshold that separates the 600- and 800-square-foot ADU limits?
- Does the asking price reflect today's single-family-plus-ADU rights, or a future district whose standards haven't been drafted?
FAQ
Can I build a duplex on an R1 lot in Ann Arbor right now?
Not under the current code. The UDC designates R1 for detached single-family homes and puts two-family dwellings in the R2 districts. An ADU is the added unit currently allowed on an R1 lot.
When will the triplex rules take effect?
There is no adopted date. The rewrite contract was approved October 5, 2026. The RFP estimated 24 to 36 months of work starting in November 2026, with Hub districts handled first and residential rules after them.
Does the new plan change parking requirements for my lot?
The rewrite is set to keep Ann Arbor's existing policy of no parking minimums and will consider maximums. The plan didn't create that policy.
If you're buying or selling in Ann Arbor while the new code is being written, Five Star Luxury Realty can help you separate a property's current entitlements from the plan's future intentions and price it on what the code allows today. Start with a free home valuation built on what your lot is actually zoned for.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
