Yes: Grand Rapids allows one ADU by right on every single- and two-family lot under Zoning Ordinance Sec. 5.9.03, with no owner-occupancy or parking requirement since Ordinance 2024-20 (April 23, 2024). A June 2026 amendment raised the size cap to 1,000 sq ft of gross floor area (the unit can never be larger than the main house) and stopped counting ADUs against the lot's accessory-structure limits. A detached unit may be 25 ft tall and must sit at least 3 ft from side and rear lot lines and 6 ft from the house; an attached unit follows the zone district's setbacks and height. The approval is a standard residential building permit through the Development Center (FY2027 fee about $750 at $100,000 of construction value, plus trade and water/sewer permits), and a deed restriction against selling the ADU separately must be recorded first. ADUs may not be rented for terms under 30 days.
Zoning & Size Requirements [1][2][3][4][5][6][7][8]
Yes — Grand Rapids allows ADUs. A detached ADU can typically be up to 1,000 sq ft under current Michigan and Grand Rapids zoning rules.
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| Allowed Zones | Permitted accessory use (by right) on all single- and two-family residential lots citywide, in every residential zone district and neighborhood classification (TN, MCN, MON); attached, interior, or detached (Sec. 5.9.03(B); Aug 2026 city FAQ). Not permitted with multi-family, mixed-use or commercial buildings; that change was deferred to the ZoneGR ordinance rewrite (June 2, 2026 briefing) |
| Max Size (Detached) | 1,000 sq ft gross floor area maximum, and the ADU may never be larger than the primary house (Sec. 5.9.03 as amended June 2026; replaced the 850 sq ft / 40%-of-house cap). Gross floor area is measured from the exterior faces of the structure. Minimum greenspace (LDR 40-60%, MDR 30-50% depending on neighborhood classification) counts all buildings, pavement, decks and patios and can limit the footprint further |
| Max Size (Attached) | Same cap: 1,000 sq ft and never larger than the primary structure (June 2026 amendment). An attached ADU is built to the primary-structure setbacks and the zone district height limit (Sec. 5.9.03(E)(1); Sec. 5.5.07). It must have its own kitchen and bathroom separate from the main unit (Aug 2026 city FAQ Q4) |
| Max Size (JADU) | Not applicable: Sec. 5.9.03 has no junior-ADU category and Michigan has no statewide JADU rule. A unit carved out inside the house is simply an attached ADU under the same 1,000 sq ft cap, with one-hour fire separation and separate air handling, meters and electrical panels (Aug 2026 city FAQ Q8) |
| Max Height | Detached ADU: 25 ft maximum (Sec. 5.9.03(G); Aug 2026 city FAQ Q6). Attached or interior ADU: the zone district's building height limit for the house (Sec. 5.5.07). The older '20 ft unless primary-structure setbacks are met' rule no longer appears in the current section text or the city's 2026 FAQ |
| Max Units | One ADU per lot (Sec. 5.9.03(A)). Must have a separate kitchen and bathroom. The former two-bedroom cap (Sec. 5.9.03(H)) was recommended for removal in the June 2026 amendment package and the city's August 2026 FAQ lists no bedroom limit; confirm with Planning (616-456-4100). A deed restriction barring separate sale must be recorded before the building permit issues (Sec. 5.9.03(K)) |
Setback Requirements [1][2][3][4][5][6][7][8]
Grand Rapids requires a rear setback of about 3 ft for a detached ADU, and no additional parking is required. Owner-occupancy is not required — you can rent it out without living on the property.
| Rear Setback | Detached ADU: accessory-structure setback of 3 ft from the rear lot line (Sec. 5.9.03(E)(2); June 2, 2026 city briefing). Attached ADU: the primary-structure rear setback of its zone district (25 ft in the Traditional Neighborhood classification). An Administrative Departure ($260) can allow a detached unit as close as 1 ft where site constraints justify it |
| Side Setback | 3 ft from side lot lines for a detached ADU (accessory-structure standard); also at least 6 ft from the house and 3 ft from any other accessory structure. Walls closer than 5 ft to a lot line trigger Michigan Residential Code fire-rating requirements. Attached ADUs use the house's side setbacks (April 2025 city FAQ Q5; accessory-structure FAQ) |
| Front Setback | A detached ADU may not be located forward of the house (no front-yard placement). An attached ADU follows the zone district's front setback for the primary structure (Sec. 5.9.03(E)(1); April 2025 city FAQ Q5). Corner-lot and alley setback relief was deferred to the ZoneGR rewrite |
| Parking Required | No parking is required for an ADU: the ADU parking requirement was eliminated by the April 23, 2024 housing policy amendments (Ord. No. 2024-20), and the current Sec. 5.9.03 text contains no parking standard |
| Owner Occupancy | Not required: the owner-occupancy rule was removed by Ord. No. 2024-20 (April 23, 2024). If the owner does not live in the ADU, the unit must be registered and certified as a rental under Chapter 140 of the City Code (Sec. 5.9.03(I)) |
| Min Lot Size | No ADU-specific minimum: an ADU may be built on any lot that meets the minimum lot area for its zone district (Sec. 5.9.03(C)), and ADUs are excluded from maximum residential density (Sec. 5.9.03(D)). Greenspace percentages, not lot area, are the usual constraint on small lots |
Permit Process & Fees [9][10][11][12][13]
An ADU permit in Grand Rapids goes through a standard permit review. Review time: not published. ADUs are a permitted use under Sec. 5.9.03, so review is the standard residential building-permit plan check with no hearing; ask the Development Center (616-456-4100) for the current turnaround. Permit fees: FY2027 residential chart (from July 1, 2026): $54 application + $6.80 per $1,000 of construction value above the first $1,000 + $25 zoning permit, so $752.20 at $100,000, $1,092.20 at $150,000 and $1,432.20 at $200,000; trade permits and water/sewer connection fees are extra.
| Approval Process | Standard residential building permit through the Development Center (1120 Monroe Ave NW, 3rd floor) via the Citizen Access portal; the applicant must be the owner or a licensed contractor, and a licensed residential contractor must pull permits and build (Aug 2026 city FAQ Q8). Submit a property survey, site plan and elevation drawings with materials and dimensions; zoning review (a $25 zoning permit) rides on the building permit, so no Planning Commission hearing is needed. Record the deed restriction (free template from planning@grcity.us) before issuance; historic-district properties also need a Certificate of Appropriateness |
| Review Timeline | Not published. ADUs are a permitted use under Sec. 5.9.03, so review is the standard residential building-permit plan check with no hearing; ask the Development Center (616-456-4100) for the current turnaround. |
| Permit Fees | FY2027 residential chart (from July 1, 2026): $54 application + $6.80 per $1,000 of construction value above the first $1,000 + $25 zoning permit, so $752.20 at $100,000, $1,092.20 at $150,000 and $1,432.20 at $200,000; trade permits and water/sewer connection fees are extra. |
| Impact Fees | None: the FY2027 Planning, Design and Development Fee Schedule lists no impact or capacity fee. Budget instead for water/sewer connection and inspection permits (a detached ADU needs its own sewer connection and, preferably, its own water connection) and a larger meter if the plumber sizes one (Aug 2026 city FAQ Q9) |
| Plan Check | Reviewed with the building permit against the Michigan Residential Code and Sec. 5.9.03: greenspace and setbacks, architectural compatibility with the house (Sec. 5.9.03(J)), one-hour fire separation, separate air handling, separate utility meters and electrical panels. The FY2027 chart shows no separate plan-review line for 1-2 family projects (plan review is otherwise 10% of the permit fee, $50 minimum) |
| Pre-Approved Plans | None for ADUs. The city's Permit-Ready Plans Program covers 3 duplex and 2 quadplex designs (single-family plans under revision); 'Publish Permit Ready ADU Plans' is a Tier 3 Task Force item with no scheduled date in the June 2, 2026 staff update |
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Construction Costs [14][15]
Building an ADU in Grand Rapids typically costs $90,000-$200,000 ($150-$250 per sq ft); a garage conversion runs $50,000-$110,000.
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| Average Build Cost | $90,000-$200,000 |
| Cost per Sq Ft | $150-$250 |
| Garage Conversion | $50,000-$110,000 |
| Prefab ADU (Installed) | $80,000-$160,000 |
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Rental Income Potential [16][17][18]
A 2-bedroom ADU in Grand Rapids rents for around $1,530-$1,650/mo, an estimated 5-11% annual return.
| Avg Rent (1 Bedroom) | $1,280-$1,470/mo |
| Avg Rent (2 Bedroom) | $1,530-$1,650/mo |
| Short-Term Rental | No: Sec. 5.9.03(I) bars renting an ADU for fewer than 30 days or using it as a short-term rental (Airbnb/Vrbo). Any leased ADU must be registered and certified through Code Compliance under Chapter 140. |
| Est. Annual ROI | 5-11% annual return |
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Recent Law Changes
What's Changed Recently
- June 2026: Sec. 5.9.03 amended on the Planning Commission's recommendation. ADU size cap raised to 1,000 sq ft (never larger than the main house), replacing the 850 sq ft / 40%-of-house rule; ADUs no longer count toward the lot's accessory-structure number or floor-area limits (Sec. 5.2.08); the two-bedroom cap was slated for removal. Home-occupation, setback and multi-family ADU changes were deferred to the ZoneGR rewrite
- June 2, 2026: Planning staff briefed the City Commission's Committee of the Whole on the amendments and the Task Force work plan: ADU guides and a fillable deed-restriction template after the ordinance update (summer 2026), a marketing campaign with the Realtors association (fall 2026), and further zoning changes in the ZoneGR rewrite (summer 2027)
- January 13, 2026: ADU Task Force (convened February 2025) delivered 20 themed recommendations to the City Commission, tiered by impact and effort
- ZoneGR comprehensive zoning ordinance rewrite: initial draft code summer-fall 2026, public review fall 2026-spring 2027, adoption targeted spring-summer 2027; ADU placement standards, corner-lot and alley setbacks, home occupations and ADUs with multi-family buildings are on its list
- April 23, 2024 (Ord. No. 2024-20, Sec. 14): ADUs became a permitted use with no Planning Commission approval, allowed with one- and two-family homes, owner-occupancy requirement removed, parking requirement eliminated, height and setback standards modified
Tips for Building an ADU in Grand Rapids
- Size math since June 2026: the cap is 1,000 sq ft of gross floor area measured from the exterior faces, but the ADU can never be larger than the main house, so a 900 sq ft bungalow still limits you to under 900 sq ft
- Check greenspace before you design: LDR lots must keep 40% (TN), 50% (MCN) or 60% (MON) of the lot green and MDR lots 30/40/50%, and every building, driveway, sidewalk, patio and deck counts against it
- An existing detached garage no longer blocks an ADU: since June 2026 the ADU is exempt from the one-attached-plus-one-detached accessory-structure count and from the accessory-structure floor-area table, and Sec. 5.9.03(F)(1) lets an accessory structure's floor area double for a second-floor ADU over a garage
- Tight lot? The city's Administrative Departure ($260 in FY2027) can let a detached accessory structure sit 1 ft from a side or rear line instead of 3 ft where site constraints justify it; an attached ADU still needs the house's full setbacks
- Record the deed restriction before you apply for the permit: Planning (planning@grcity.us) provides a free template, and the ADU cannot be sold separately from the house
- If you plan to rent it, budget for rental registration and certification under Chapter 140 and plan on 30-day-minimum leases; short-term rental of an ADU is prohibited
- Fee reality check: at $150,000 of construction value the FY2027 building permit is $1,092.20 (application $54 + $6.80 per $1,000 + $25 zoning); electrical, mechanical and plumbing permits and water/sewer connection permits are on top, and only city crews may tap a live water main
- Cost basis: build and conversion ranges are national ADU cost guides (HomeGuide, Angi, mid-2026) applied to West Michigan labor rates, not Grand Rapids quotes; rents anchor on HUD's FY2026 Fair Market Rents for Kent County ($1,278 one-bedroom, $1,531 two-bedroom) with listing-site averages as the upper bound
- Cost basis (2026-09-20 re-verification): short term allowed: No: Sec. 5.9.03(I) bars renting an ADU for fewer than 30 days or using it as a short-term rental (Airbnb/Vrbo). Any leased ADU must be registered and certified through Code Compliance under Chapter 140. The Task Force's short-term-rental idea was not part of the June 2026 amendments
ADU Builders in Grand Rapids
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Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Residential FAQs: Accessory Dwelling Units — City of Grand Rapids Planning Department (August 2026) Planning Department — Accessed 2026-09-20
- Grand Rapids Zoning Ordinance Sec. 5.9.03 Accessory Dwelling Units (as amended by Ord. No. 2024-20) — city-posted section text Municipal Code — Accessed 2026-09-20
- ADU Program & Recommended Zoning Code Amendments — City Commission Committee of the Whole briefing, June 2, 2026 city_website — Accessed 2026-09-20
- City Housing Policy Amendments (ADU text amendments adopted April 23, 2024) — City of Grand Rapids Planning Department Planning Department — Accessed 2026-09-20
- Grand Rapids Code of Ordinances, Chapter 61 Zoning Ordinance, Article 9 Use Regulations (Municode) Municipal Code — Accessed 2026-09-20
- FAQs: Accessory Dwelling Units — City of Grand Rapids Development Center (April 2025) Planning Department — Accessed 2026-09-20
- ADU Task Force Recommendations, January 2026 — City of Grand Rapids city_website — Accessed 2026-09-20
- Zoning FAQs: Accessory Structure Placement — City of Grand Rapids Development Center Planning Department — Accessed 2026-09-20
- FY 2027 Planning, Design and Development Fee Schedule (effective July 1, 2026) — City of Grand Rapids fee_schedule — Accessed 2026-09-20
- Building Permit Fee Estimator — Grand Rapids Development Center building_dept — Accessed 2026-09-20
- Residential Building Permits — Grand Rapids Development Center building_dept — Accessed 2026-09-20
- Permit-Ready Plans Program — City of Grand Rapids Planning Department Planning Department — Accessed 2026-09-20
- Residential FAQs: Accessory Dwelling Units — City of Grand Rapids Planning Department (August 2026) Planning Department — Accessed 2026-09-20
- How Much Does It Cost to Build an ADU? — HomeGuide industry — Accessed 2026-07-10
- How Much Does an ADU Cost to Build? — Angi industry — Accessed 2026-07-10
- FY 2026 Fair Market Rents — Grand Rapids-Wyoming, MI HUD Metro FMR Area (Kent County) Government Data — Accessed 2026-09-20
- Average Rent in Grand Rapids, MI — RentCafe Market Data — Accessed 2026-07-10
- Average Rent in Grand Rapids, MI — Zumper Market Data — Accessed 2026-07-10
Frequently Asked Questions
Can I build an ADU in Grand Rapids?
Yes. ADUs are allowed in Permitted accessory use (by right) on all single- and two-family residential lots citywide, in every residential zone district and neighborhood classification (TN, MCN, MON); attached, interior, or detached (Sec. 5.9.03(B); Aug 2026 city FAQ). Not permitted with multi-family, mixed-use or commercial buildings; that change was deferred to the ZoneGR ordinance rewrite (June 2, 2026 briefing) in Grand Rapids. The maximum size for a detached ADU is 1,000 sq ft gross floor area maximum, and the ADU may never be larger than the primary house (Sec. 5.9.03 as amended June 2026; replaced the 850 sq ft / 40%-of-house cap). Gross floor area is measured from the exterior faces of the structure. Minimum greenspace (LDR 40-60%, MDR 30-50% depending on neighborhood classification) counts all buildings, pavement, decks and patios and can limit the footprint further. Owner-occupancy is not required, so you can rent out the ADU.
How much does an ADU cost in Grand Rapids?
ADU construction in Grand Rapids typically costs $90,000-$200,000. Garage conversions run $50,000-$110,000, and prefab ADUs cost $80,000-$160,000.
How much can I rent an ADU for in Grand Rapids?
Average ADU rents in Grand Rapids are $1,280-$1,470/mo for a 1-bedroom and $1,530-$1,650/mo for a 2-bedroom unit.
Do I need parking for an ADU in Grand Rapids?
No parking is required for an ADU: the ADU parking requirement was eliminated by the April 23, 2024 housing policy amendments (Ord. No. 2024-20), and the current Sec. 5.9.03 text contains no parking standard. Check with Grand Rapids planning department for the latest Michigan ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in Grand Rapids?
Grand Rapids does not publish a standard ADU review timeline. ADUs are a permitted use under Sec. 5.9.03, so review is the standard residential building-permit plan check with no hearing; ask the Development Center (616-456-4100) for the current turnaround. Permit fees: FY2027 residential chart (from July 1, 2026): $54 application + $6.80 per $1,000 of construction value above the first $1,000 + $25 zoning permit, so $752.20 at $100,000, $1,092.20 at $150,000 and $1,432.20 at $200,000; trade permits and water/sewer connection fees are extra.
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