Earlier editions: 2026-09
Title 18 — SIGNS AND DISPLAY ADVERTISING
Sonoma Municipal Code Ch. 18.60 Appendices
Sonoma Municipal Code · 2026-10 edition · updated 2026-10-05 · Sonoma
Cite as: Sonoma Municipal Code Chapter 18.60 · Text as of 2026-10-05
18.60.010 Appendix A – Design guidelines for signs.¶
General Purpose.The purpose of architectural review of signs is to ensure that their design and placement will be compatible with the buildings on, or near to which, they are located, and will further the unique and pleasant atmosphere of Sonoma through a variety of attractive signs. The applicant should be aware of Sonoma’s character before designing a sign and should design it with the style of the building and the ambience of the town in mind. A sign should be architecturally a part of the design of the building that it is identifying rather than a feature independent of and in conflict with the design of the building.
The following guidelines should assist the designer in determining what would be appropriate and what would not be appropriate. These guidelines have been categorized into various elements of signage, including size, material, color, letter style, lighting, placement, and logos, symbols or pictures. These elements, however, must fit together to create the sign, which in turn must be considered on the basis of its total appearance.
Note: These design guidelines are general, and should be used only as a guide in designing a sign. They are based on the existing buildings in town, but may not cover every situation.
Size.Although the maximum size of the sign is controlled by this title, the size of the sign shall be considered in relation to the building mass involved and the other elements mentioned herein, especially the sign’s placement. A flat wall sign can be considerably larger than other types of signs as flat signs are not generally obtrusive. Projecting signs normally encroach into the right-of-way and need less size to be noticeable. Detached, freestanding signs are the most obvious type of sign, and therefore also need considerably less size than a wall sign, nor are they dependent on a building structure for placement, but can be placed to the best advantage on the site.
Larger signs are justified in areas where business is primarily dependent upon vehicular traffic while smaller signs can be sufficient for pedestrian traffic areas. A sign out of proportion in size with others in the area is not to be encouraged, even though possibly within the maximum of this title. Any sign permitted to exceed the maximum sign size as established by this title by reason of any additional size permitted must be determined to be unobtrusive, necessary and not out of proportion to other signs in the area.
Materials.Materials should be considered in relation to the building involved as well as to the town in general. Sign materials chosen should be geared to the architecture and materials of the building for which the sign is being designed.
Adobe-Spanish Style Buildings: For “adobe” and “Spanish style” buildings, where stucco, cement block, slumpstone and so forth are the main components, natural wood with painted or carved lettering is the most appropriate sign material, as it was the signing material used with this type of construction in historical times.
Brick and Stone Buildings: A brick or stucco building of the early 20th century style is most adaptable to a painted wooden sign or even exposed neon tubing on plastic. A permit for a neon sign will be granted only in exceptional cases (when the design of the sign is especially pleasing and appropriate with the building).
Wooden or “Old West” Buildings: Wooden Victorian style buildings echoing the late 19th, early 20th century and Old West period are generally most compatible with painted or natural wood signs. At times, some alternate material might be made to resemble wood or can have a similar effect. For example, plastic may be made to resemble natural or painted wood in color, but the total effect is rarely that of the copied material. Great care should be taken in designing plastic signs with interior illumination because such signs may be incongruous with historic architecture. When plastic is to be used, careful attention should be given to all of the other elements of design.
A number of the 19th and 20th century buildings have made excellent use of painted signs on the windows. Again, great care should be taken when using this signing method as, when used improperly, it can present a cluttered appearance to the window. When used properly, this signing method can be very appropriate and emphasize the period of the building.
Color.The color(s) of a sign should be harmonious and complementary to the colors of the building on or near which it is to be located. Fewer colors will generally produce the most attractive sign. The colors should also be reasonably compatible with the general character of Sonoma (psychedelic or phosphorescent colors really do not belong in Sonoma). In some cases, the color of the sign can make a rather incompatible material more compatible with the building.
Letter Style.The letter style to be used on a sign should also be based on the architectural style of the building. Simple block letters are generally most compatible with the Mexican style buildings.
More intricate lettering is generally appropriate for the wooden Victorian style. There are numerous styles of lettering that could be used including Old English, Stencil, Cloister, and Quill Script. Block lettering would also be appropriate for the Victorian and early to middle 20th century buildings. For those buildings more recently constructed and having no particular architectural style, simpler letter styles are probably the most desirable.
Lighting.It must be recognized that illuminated signing is a development of the 20th century. However, it is recognized that illuminated signs have some advantage over some nonilluminated signs in identifying businesses at night. Generally, illuminated signs are inappropriate except for businesses which normally operate in the evening hours.
For those cases where illumination is determined essential by the design review and historic preservation commission, it shall be as subtle as possible. Whenever a sign is to abut a residential area, the illumination times and location of the sign will be carefully considered.
Exterior Illumination: Illumination from concealed lights is the most appropriate means of illumination for most signs. It is also the most preferable method of illumination for maintaining the historical integrity of the sign and the building. Such flood lights should not be excessive in brilliance and must be shielded. Flood lights must be concealed in some manner (landscaping or a building feature is often used).
Interior Illumination: Interior illumination is generally most appropriate for smaller signs or signs a distance away from the Plaza area. Within the Plaza area large interior illuminated signs are not complementary to the character of most of the shops, though smaller signs might be designed with careful attention to the other elements so that they would be harmonious with the area. The less white or light-colored surface there is on a sign, the less glaring an illuminated sign will be. Darker colors will tone down the lighting of a sign considerably. Illumination levels shall be kept to the minimum necessary to provide legibility at normal sight distances. No interiorly illuminated sign is allowed in any residential zoning district.
Placement.Proper placement of the sign basically depends on the movement of the possible customer traffic within the area and the type of business involved. If the business is on an arterial street, the sign will have to be obvious to fast moving vehicular traffic. Projecting or detached signs or more obvious wall signs are therefore appropriate. If the business is in, or on the fringes of, a heavily traveled pedestrian area, small projecting signs or flat wall signs are adequate to identify the business to the slower traffic, which is probably giving their entire attention to the stores they are passing. Detached permanent signs are, in most cases, unnecessary and unattractive in pedestrian-oriented areas.
It has been found that small sidewalk signs placed during business hours may add interest and direct foot traffic to shops; however, specific guidelines have been established to prevent an excessive number of signs. Second story or multiple suites will be encouraged to share sidewalk sign space to eliminate congestion. Where a sidewalk sign already exists, there will be, as a general rule, 18 feet between it and any adjacent sidewalk sign; however, each case will be studied individually. A judiciously placed projecting sign may offer better identification than a sidewalk sign in some locations. Placement of a sidewalk sign shall be as approved by the design review and historic preservation commission.
The placement of signs should also take into consideration the architectural style of the building. For Spanish style buildings, flat wall signs, very small projecting signs, and low profile detached signs are in keeping with the historic feeling and aesthetic appearance of the building. Flat wall signs and smaller projecting signs, as well as painted window signs, are most appropriate for wooden Victorian style buildings. Larger freestanding signs generally tend to fail to carry the historical continuity of Sonoma, and should be considered carefully before being proposed.
Architectural treatment of the supporting mechanism of the signs can make them more compatible with the building involved and with the rest of the town. This can be accomplished by mounting the sign in a planter, covering the post with various building materials, or using materials for the entire sign which have been suggested earlier as being complementary to the building involved.
Roof signs are regulated stringently by this title. Placement of a sign on a roof interrupts the architectural lines of a building, oftentimes making the building appear cluttered. Roof signs should be used only when the silhouette of the sign is not in conflict with the silhouette of the rooflines of the building.
The placement of any new sign or replacement of an existing sign shall not obstruct the visibility of an existing sign whenever it can be avoided.
Logos, Symbols, and Pictures.For certain types of businesses, a logo or symbol is an integral part of identification, such as the various oil company logos, the mortar and pestle symbol for drug stores, and the cocktail glass for an on-sale liquor establishment. For such businesses, it will normally be appropriate for such symbols to be included in identification signs. Such symbols should be in proper scale considering the overall size of the sign, and should be only supplementary to the total identification information of the sign. Other businesses may wish to use a symbol or picture as a means of identifying the nature of the business. This might be done in a subtle manner according to the guidelines suggested for colors and materials. It is suggested that only one logo or symbol be used for a single business, and that, in general, the size of the logo, symbol or picture be kept small. (Ord. 01-2015 § 1, 2015; Ord. 06-2013 § 3, 2013; Ord. 03-2011 § 1, 2011; Ord. 2000-9 § 1, 2000).
18.60.030 Appendix B – City of Sonoma lighting application standards.¶
| Watts per square foot generally required for measure in bold | |||||
|---|---|---|---|---|---|
| Application | Maximum Footcandles (3' above ground level) | Tungsten-Halogen | Mercury Units | Metal-Halide | High-Pressure Sodium |
| Watts per square foot generally required for measure in bold | |||||
|---|---|---|---|---|---|
| Application | Maximum Footcandles (3' above ground level) | Tungsten-Halogen | Mercury Units | Metal-Halide | High-Pressure Sodium |
| Automobile Sales | |||||
| Front row | 50 | 10.0 | 4.5 | 2.9 | 2.0 |
| Remainder | 10 | 1.5-1.8 | 0.68-.81 | 0.44-.52 | 0.3-.36 |
| Billboards/ Signs | |||||
| Good contrast | 20-50 | 4.3-10.0 | 1.94-4.5 | 1.25-2.9 | 0.86-2.0 |
| Poor contrast | 50-100 | 10.0-20 | 4.5-9 | 2.9-5.8 | 2.0-4 |
| Buildings | |||||
| Light surfaces | 15 | 1.2/3.3 | .54/1.5 | .35/.96 | .24/.66 |
| Medium surfaces | 10-20 | 2.2-4.3 | 1-1.94 | .64-1.25 | .44-.86 |
| Dark surfaces | 50 | 10 | 4.5 | 2.9 | 2 |
| Parking Lots | |||||
| Attendant parking | 2 | 0.38 | 0.17 | 0.11 | 0.075 |
| Industrial lots | 1 | 0.13-.15 | 0.06-.07 | 0.037-.044 | 0.026-.03 |
| Self-parking lots | 1 | same | " | " | " |
| Protective/ |
|||||
| Gates and entries | 5 | 1.2 | 0.54 | 0.35 | 0.24 |
| Building surrounds | 1 | 0.15-.19 | 0.07-.09 | .044-.055 | 0.03-.04 |
| Roadways | |||||
| Along buildings | 1 | 0.24 | 0.11 | 0.07 | 0.05 |
| Open areas | .5 | 0.08-.1 | 0.036-.045 | 0.023-.029 | 0.02 |
| Service Stations | |||||
| Front and canopy areas | 20-50 | 4.3 | 1.94 | 1.25 | 0.86 |
| Rear areas | 5-10 | 1.2 | 0.54 | 0.35 | 0.24 |
| Shopping Centers | |||||
| Neighborhood | 5 | 0.65 | 0.29 | 0.19 | 0.13 |
| General commercial | 5 | same | " | " | " |
| Heavy traffic | 10 | 1.5-1.8 | 0.68-.81 | 0.44-.52 | 0.3-.36 |
| Parking areas | 5 | 0.65 | 0.29 | 0.19 | 0.13 |
| Buildings-front | 5 | 0.24 | 0.11 | 0.07 | 0.05 |
| Storage Yards | |||||
| Active | 20 | 3.6-4.3 | 1.6-1.94 | 1.04-1.25 | 0.72-.86 |
| Inactive | 1 | 0.15-.19 | 0.07-.09 | 0.044-.055 | 0.03-.04 |
(Ord. 01-2015 § 1, 2015; Ord. 2000-9 § 1, 2000).
18.60.050 Appendix C – Applicable Business and Professions Code sections.¶
Repealed by Ord. 01-2015. (Ord. 2000-9 § 1, 2000).
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