# Sign Regulations in Mercer Island, Washington

Sign permit rules, size and height limits, setbacks, and ordinance citations for Mercer Island, Washington, compiled by PermitPal from the jurisdiction's published municipal code.

- **Jurisdiction:** Mercer Island, Washington (WA)
- **Canonical page:** https://permitpal.io/sign-regulations/washington/mercer-island
- **Data last verified:** 2025-07-03
- **Source:** [municode municipal code](https://library.municode.com/wa/mercer_island/codes/city_code?nodeId=CICOOR_TIT19UNLADECO)

## At a glance

Mercer Island, Washington regulates 13 sign types across 6 zoning districts. Freestanding Ground Signs in the Single-Family (R-8.4, R-9.6, R-12, R-15) zoning district are capped at 42 inches tall and 18 square feet (non-single-family dwelling uses), with a Minimum 10 ft from public right-of-way; 35 ft from abutting properties (applies primarily to public schools). setback (Sec. MICC 19.12.080(B)(3),(10)). Most commercial signs in Mercer Island require a permit.

## Sign rules by zoning district (6 zones)

| Zoning District | Sign Types Regulated | Max Height | Max Area | Permit Required |
| --- | --- | --- | --- | --- |
| Single-Family (R-8.4, R-9.6, R-12, R-15) | 3 | 42 inches | 18 square feet (non-single-family dwelling uses) | — |
| Multiple-Family (MF-2L, MF-2, MF-3) | 2 | 42 inches (within 10 ft from the property line facing a street); up to 6 ft if more than 10 ft from line | 25 square feet per individual business or building; 40 square feet for joint tenant directory sign at entrance | — |
| Business (B), Planned Business (PBZ), Commercial Offices (C-O) | 5 | A-Frame: 60 inches | 25 square feet per individual business; 40 square feet for joint tenant directory sign | — |
| Public Institution (PI) | 3 | 42 inches | 18 square feet | — |
| Open Space (OS) | 2 | 10 ft | 15 sq ft display area (or 22 sq ft if >100 acres open space) | — |
| Town Center (TC) | 5 | A-frame: 60 in | 25 square feet per business; 40 sq ft for joint tenant sign at entry | — |

## Zone-by-zone sign requirements (sample of 3 of 6 zones)

### Single-Family (R-8.4, R-9.6, R-12, R-15)

| Sign Type | Max Height | Max Area | Max Width | Setback | Signs Allowed | Location | Permit Required | Ordinance Citation |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Wall Sign | — | 12 square feet (non-single-family dwelling uses); 72 square inches (licensed practitioners or service operators) | — | — | One wall sign per public street frontage per non-single-family-dwelling use / One unlighted window or wall sign for practitioners/service operators | On the public street frontage for the use. For licensed practitioners/service operators in residential zones, in window or wall for identification only. | — | MICC 19.12.080(B)(3),(4),(10),(11) |
| Freestanding Ground Sign | 42 inches | 18 square feet (non-single-family dwelling uses) | — | Minimum 10 ft from public right-of-way; 35 ft from abutting properties (applies primarily to public schools). | One per public street frontage per non-single-family-dwelling use | On public street frontage. Must be set back a minimum of 10 feet from public right-of-way and 35 feet from abutting properties (for public school). | — | MICC 19.12.080(B)(3),(10) |
| Electronic Readerboard (Option for Public Schools) | 42 inches (if ground sign) | 12 square feet (if wall sign) or 18 square feet (if ground sign, cannot exceed as per general rule) | — | Same as freestanding sign if on a ground sign: 10 ft from ROW, 35 ft from abutting prop. | Maximum one electronic readerboard per public school | On permitted wall or ground sign, typically on public school campus; subject to setback rules for ground sign. | — | MICC 19.12.080(B)(10-11) |

### Business (B), Planned Business (PBZ), Commercial Offices (C-O)

| Sign Type | Max Height | Max Area | Max Width | Setback | Signs Allowed | Location | Permit Required | Ordinance Citation |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Wall Sign | — | 25 square feet per individual business; 40 square feet for joint tenant directory sign | — | Cannot project above parapet/roofline/etc. | One wall sign per business per street frontage; joint tenant sign at main entrance allowed | One per street frontage, on each business store frontage; each business may have additional for entry facing driveway/parking lot if that is primary public entry. | — | MICC 19.12.080(B)(2); PBZ: MICC 19.04.010(D)(4); Town Center MICC 19.11.140(B)(2) |
| Freestanding Ground Sign | 42 inches if within 10 ft of property line; up to 6 ft otherwise | 25 square feet (in front/side yard setbacks); 40 sq ft if joint tenant sign and not in setback (max 6 sq ft per business) | — | 42" max height within 10 ft of property line; up to 6 ft max if setback more than 10 ft. | One ground sign per street frontage | On public street frontage for business/complex. | — | MICC 19.12.080(B)(1); PBZ: 19.04.010(D)(4); Town Center: 19.11.140(B)(1) |
| Projecting Sign | — | 6 square feet | — | Must clear sidewalk by at least 8 ft. | Not specifically limited but combinations with wall and ground sign counts apply. | On facade along retail/street frontages | — | MICC 19.12.080(B)(9)(b); Town Center: 19.11.140(B)(3) |
| Window Sign | — | 25% of window area (Town Center/PBZ only) | — | — | Not specified, within area limits | On retail ground level window area | — | MICC 19.12.080(B)(9)(c); 19.11.140(B)(4) TC |
| Temporary Commercial Sign (A-Frame, Banner, Streamer) (Option for B, PBZ, TC) | A-Frame: 60 inches | A-Frame: up to 24 square feet (both sides counted); Banner: 10 sq ft per 10 ft of business facade (max 48 sq ft) | — | A-frame must be placed to allow pedestrian passage; on public ROW only with permission. | A-frame: 1 per business; Banner: 1 per building face per business | A frame: within 100 ft of the business and on private property or public ROW with conditions. Banner: attached to building; Streamers: attached to building. | — | MICC 19.06.020(C) |

### Town Center (TC)

| Sign Type | Max Height | Max Area | Max Width | Setback | Signs Allowed | Location | Permit Required | Ordinance Citation |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Wall Sign (Town Center) | — | 25 square feet per business; 40 sq ft for joint tenant sign at entry | — | Prohibited above parapet/eave/roofline. | One wall sign per storefront/street frontage; joint entry sign allowed | On building facade for business facing street or main entry. | — | MICC 19.11.140(B)(2) |
| Freestanding Ground Sign (Town Center) | 42 inches if within 10 ft property line; 6 ft if set back >10 ft | 25 sq ft (individual); 50 sq ft joint complex sign (6 sq ft per business, more allowed if >5 businesses) | — | If within 10 ft, 42 in max; if more than 10 ft, 6 ft max. | One per street frontage | On street frontage | — | MICC 19.11.140(B)(1) |
| Projecting Sign (Town Center) | — | 6 sq ft | Projects no more than 4 ft from building; at least 8 ft sidewalk clearance | 8 ft min sidewalk clearance | — | On building facade along public way | — | MICC 19.11.140(B)(3) |
| Window Sign (Town Center) | — | 25% of window area | — | — | — | On windows facing public way | — | MICC 19.11.140(B)(4) |
| Temporary Commercial Signs (Town Center) (A-Frame, Banner, Streamer) | A-frame: 60 in | A-Frame: 24 sq ft (2 sides combined); Banner: up to 10 sq ft per 10 ft of building face, max 48 sq ft | — | A-frame must permit pedestrian passage. | A-frame: 1 per business; Banner: 1 per face; Streamer: limited times/uses | A-Frame: within 100 ft of business on private property or public ROW; Banner: building facade; Streamer: attached to building | — | MICC 19.06.020(C) |

## Prohibited signs in Mercer Island

- Any signs, except as permitted by this Code, or other city or state regulation, are prohibited in all zones (MICC 19.06.010.F).
- Electric fences, barbed wire fences, or similar fences that could pose a safety risk are not allowed (MICC 19.02.050.F).
- Signs shall not obstruct vehicular or pedestrian traffic (MICC 19.06.020.A.3).
- Signs attached to utility poles, traffic signs, street signs, or trees are specifically forbidden (MICC 19.06.020.A.6.c).
- Window or exterior displays of goods or services which depict, simulate, or are intended for use in connection with specified sexual activities are prohibited (MICC 19.04.050.B.27.d, MICC 19.06.110.A.3.b.iv).
- Animated, moving, flashing, blinking, reflecting, revolving, or other similar signs or signs that incorporate these elements are prohibited (MICC 19.11.140.B.8.b, MICC 19.12.080.B.9.h).
- Pennants or inflated signs, balloons and figures are prohibited, except as specifically allowed by section (MICC 19.11.140.B.8.c, MICC 19.12.080.B.9.d).
- Signs attached to or painted on vehicles parked and visible from the public right-of-way are prohibited if their primary purpose is as a stationary sign (MICC 19.11.140.B.8.d, MICC 19.12.080.B.9.j).
- Off-premises signs (signs related to a building, business, tenant or establishment not located on the same premises as the sign) are prohibited (MICC 19.12.080.B.9.i).
- Signs mounted on the roof are prohibited (MICC 19.11.140.B.8.a, MICC 19.12.080.B.9.a).
- Internally lit signs are prohibited outside of the PBZ (Planned Business Zone) (MICC 19.12.080.B.9.e).
- Neon signs are prohibited outside of the PBZ (MICC 19.12.080.B.9.f).
- Projecting signs are prohibited in all zones other than PBZ (MICC 19.12.080.B.9.b).

## Signs exempt from permit in Mercer Island

- Official traffic signs or signals, public notices, and governmental flags are excluded from the definition of 'sign' (MICC 19.16.010).
- Any sign that is not visible from outside the property or from any public right-of-way is generally not regulated (implied by context, not cited directly).
- Temporary, noncommercial signs such as those expressing public/community events, religious, political, ideological, or other philosophical messages are allowed in all zones, subject to general temporary sign rules (MICC 19.06.020.B.1).
- Temporary commercial signs in the form of real estate signs and garage sale signs are allowed in all zones, subject to specified conditions (MICC 19.06.020.B.2).
- Temporary commercial signs in the form of banners, A-frame sandwich boards and streamers are allowed in TC, B, and PBZ zones under specific restrictions (MICC 19.06.020.C).
- These sign ordinances do not apply to: fences required by state law to enclose public utilities; chain link fences enclosing school grounds or public playgrounds; screens used for safety measures in public recreation areas such as ballfields (except as otherwise provided) (MICC 19.02.050.G).

## Sign plan & submission notes

- When multiple signs for individual businesses are contemplated for a major construction project in the Town Center, a master sign plan stipulating the location and size of future signs will be required (MICC 19.11.140.B.2.g, MICC 19.11.140.B.12).
- Within zones outside the Town Center, when multiple signs for individual businesses in one building or multiple buildings in a complex are contemplated, a master signage plan stipulating the location and size of allowed signs shall be required (MICC 19.12.080.B.2.e).
- For Planned Business Zone (PBZ), a site plan (PBZ site plan) must be filed and approved by the design commission, and major new construction requires conformance with this site plan (MICC 19.04.010.G.1, H.2.a).

## Full detail

This page publishes an overview of every zoning district plus a sample of 3 districts in full. Complete zone-by-zone requirements for all 6 zoning districts in Mercer Island — every sign type, every field — are available with a free PermitPal account: https://app.permitpal.io/?address=Mercer+Island+WA&override=true&utm_source=landing&utm_medium=city-page&utm_campaign=city-mercer-island

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