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Project Title: |
Development Plan for a Kensington Design Review and Variance for a Residential Addition |
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County File(s): |
CDDP25-03032 |
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Applicant: Owner: |
Greg VanMechelen | VanMechelen Architects Ken and Julie Kurtzman |
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Zoning: |
R-6 Single-Family Residential District (R-6), Kensington Combining District (-K), Tree Obstruction of Views Combining District (-TOV) |
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General Plan: |
Residential Medium Density (RM) |
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Site Address/Location |
210 Amherst Avenue, Kensington / APN: 570-050-004 |
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California Environmental Quality Act (CEQA) Status: |
Categorical Exemption, CEQA Guidelines Section 15301(e)-Additions to existing structures. |
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Project Planner: |
Diana Lecca, Project Planner - phone: (925) 655-2869 and email: diana.lecca@dcd.cccounty.us |
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Staff Recommendation: |
Approve (See section II for full recommendation) |
I. PROJECT SUMMARY
The applicant requests approval of a Kensington Design Review Development plan to allow a 398 square-foot addition to the existing residence as well as an 88-square-foot deck addition. The project results in a gross floor area (GFA) of 3,131 square feet, where 2,500 square feet is the GFA threshold necessitating public hearing. The project scope also includes a Variance for rear setback of 5-foot 10-inches (where 15 feet is the minimum).
II. RECOMMENDATION
The Department of Conservation and Development, Community Development Division (CDD) staff recommends that the Zoning Administrator:
1. OPEN the public hearing for the Development Plan, Variance and Kensington Design Review (County File #CDDP25-03032), ACCEPT public testimony, and CLOSE the public hearing.
2. DETERMINE that the proposed project is exempt from the California Environmental Quality Act (CEQA), under CEQA Guidelines Section 15301(e);
3. APPROVE the Development Plan, Variance and Kensington Design Review (County File #CDDP25-03032), based on the attached Findings and Conditions of Approval;
4. DIRECT staff to file a Notice of Exemption with the County Clerk.
III. GENERAL INFORMATION
A. General Plan - The subject property is located within a Residential Medium Density (RM) General Plan Land Use designation.
B. Zoning District - The subject property is located within the R-6 Single-Family Residential District (R-6), Kensington Combining District (-K), and Tree Obstruction of Views Combining District (-TOV).
C. California Environmental Quality Act (CEQA) - The proposed project is exempt under CEQA Guidelines Section 15301(e) - existing facilities including additions to existing structures provided that the addition will not result in an increase of more than 50 or 2,500 square feet. The proposed project will add approximately 400 square feet to the residence. Therefore, the project is exempt under CEQA Guidelines Section 15301(e) which exempts additions to existing structures.
D. Lot Creation: The subject property was created as lot number 4 under the Berkeley Highlands Subdivision , Block C on April 13, 1912.
E. Previous Applications: No previous planning entitlements. Current application is accompanied by an Accessory Dwelling Unit application (CDSU25-00152) which shall be processed upon approval of County File CDDP25-03032
IV. SITE/AREA DESCRIPTION
The project site is a 4,995-squre-foot parcel located on the western side of Amherst Avenue in the unincorporated area of Kensington. The parcel is a regular rectangular shaped lot, not unlike several along Amherst Avenue. The site includes a two-story single-family residence with a garage and a wood deck. The property features a distinctive downward-sloping topography, starting at 562 feet above mean sea level at the front of the property (along Amherst Avenue), descending to 548 feet above mean sea level, at the rear of the property. The steep, winding terrain is found to be common throughout the Kensington hills. Due to the hillside grade, the residence configuration starts with a street-level entry. This slope allows the home to cascade naturally with the land, resulting in a dual-level layout where the lower level transitions into the terraced backyard garden. The subject property is surrounded entirely by other residences.
Surrounding properties are predominantly rectangular, typically at 50 feet in width with a few exceptions, and approximately 100 feet to 115 feet in depth, with a few reaching 130 and 140 feet in depth. All properties in the immediate vicinity share the same zoning as the subject property of R-6, -TOV and -K. The vast majority of the properties in the area share the General Plan designation of Residential Medium Density (RM) General Plan. The Kensington Police Department, located southwest of the subject property, is the only outlier with a Public and-Semi Public (PS) General Plan designation.
V. PROJECT DESCRIPTION
The applicant requests approval of a Kensington Design Review Development Plan to allow a 398-square-foot addition to the rear of an existing single-family residence. The project results in a gross floor area (GFA) of 3,131 square feet, where 2,500 square feet is the GFA threshold necessitating a public hearing. The proposed addition is located primarily on the lower level of the single-family residence, converting 145 square feet of non-habitable space into habitable space, and adding 150 square feet of new area. The second portion of the addition is a 103 square-foot kitchen expansion located on the second (and main level) and it faces the front of the residence, although remains screened by the existing garage. The application also includes a Variance request for a 5-foot 10-inches rear yard (where 15 feet is the minimum) for the lower portion of the addition, this area will be utilized for a proposed Accessory Dwelling Unit (ADU). The overall project also includes a deck expansion of 88 square feet facing the rear of the property.
VI. AGENCY COMMENTS
A. Kensington Municipal Advisory Council (KMAC): On December 10, 2025, the KMAC held a meeting to discuss the project. The KMAC voted unanimously to approve CDDP25-03032.
B. Health Services Department: Environmental Health: In a comment letter dated December 1, 2025, Environmental Health staff provided comments and additional requirements if the project were to be serviced by a supply well. Given that the project is served by a sanitary district, the comments are not applicable.
C. East Bay Municipal District: In a comment letter dated December 11, 2025, the water district requested that the applicant contact them and request a service estimate.
No comments were received from the following agencies: Conservation and Development Building Inspection Division, Kensington Fire Protection District, Stege Sanitary District, and Contra Costa Mosquito & Vector Control District.
VII. STAFF ANALYSIS AND DISCUSSION
A. Consistency with General Plan: The subject property is located within the Residential Medium Density (RM) General Plan Land Use designation. The RM designation allows for a residential density between 7-17 units per net acre. Primary uses in the RM are predominately single-family residential development which typically includes a detached single-family unit on lots approximately 2,500 to 6,000 square feet. The parcel has a residential density of 0.8 units to 2.0 units; therefore, given that the project will be for a residential addition and an Accessory Dwelling Unit, the project conforms to the residential density of the RM designation. The project includes an addition which increases living area within the existing single-family residence by 398 square feet. The proposed addition does not change the established residential use of the site, its residential density, or lot size. Thus, the residential project is clearly consistent with the intent and purpose of the RM designation.
Specific Area Policies:
The project is also subject to the Kensington Policies # 1 through 14 of the General Plan Stronger Communities Element. Collectively, these policies promote for emergency preparedness, provide for reasonable review of new residential development with protection for existing residences in the Kensington community, and encourage development of diverse housing stock, public services and infrastructure, and open space. The relevant policies applicable to the proposed minor residential addition include Kensington Policies #3 through #5, which require the proposed project to be evaluated for view impacts, design compatibility, privacy, and solar access. As discussed below, the project is consistent with all applicable Kensington Policies within the County General Plan
Kensington Policy 3. Ensure new development provides reasonable protection for existing residences regarding views, design compatibility (including building mass, height, and mechanical devices), adequate parking, privacy, and access to sunlight.
1. Views: The construction of the residential addition of approximately 400 square feet will not impact any surrounding views as defined in Chapter 84-74 - Kensington Combining District (-K), Section 84-74.404(r). Although there is a change in height (approximately 9 inches), this is due to the lower existing downslope grade at the west of the property. The overall residence sits at 23 feet 3inches, which is below the 35-foot height maximum. The parcel is located on the northwest portion of Amherst Avenue and is located on a downslope (lower elevation towards Arlington Avenue). Given that the larger addition is on a lower level, and thus hidden by the topography and vegetation, and the second portion of the addition is towards the inner deck, the project would not result in adverse effects on views enjoyed from surrounding properties. The surrounding topography, and the location of the project relative to living space within adjacent residences, ensures that the project minimizes view impacts.
2. Design Compatibility; Bulk: The existing residence is built on a lot with a negative slope away from the street frontage. A portion of the new development is within the existing building envelope, while the other portion of the addition is at a lower elevation, away from the public view and utilizes part of the existing non-habitable space. The perceived bulk is not significantly altered as the addition aims to remain primarily within the existing footprint, only expanding where needed at the lower level.
3. Design Compatibility; Size: The new total gross floor area of the residence will be 3,131 square feet. Although the new total exceeds the 2,500-square-foot gross floor area maximum for the subject property, thus resulting in a public hearing; the size is not excessive as there are other residence along Amherst Avenue that exceed 2,500 square feet, with residences even exceeding 4,000 square feet along the same street. Additionally, the original gross floor area already exceeded the threshold. As a result, any common and typical addition would exceed the Kensington gross floor area threshold. Therefore, the proposed project remains compatible with the surrounding area.
4. Design Compatibility; Height: The proposed additions do not exceed the 35-foot heigh maximum. The overall height of the residence with the proposed addition reaches between 23 feet 3 inches and 23 feet 6 inches due to slope variation. Additionally, neither addition nor the new deck exceed the two and on-half story building height limit.
5. Adequate Parking: The R-6 Zoning District standards require two off-street parking spaces unless the parcel was created prior to September 9, 1971, in which case a single parking space would be required. The current property has a two-car garage already in existence. The proposed addition does not alter the current parking situation, nor does it adjust the garage. Therefore, the project maintains adequate parking expected for the neighborhood.
6. Privacy: The project proposes a lower-level conversion and addition located at the rear of the residence, and a separate addition facing the internal deck but screened behind the existing garage, which faces the street. The proposal results in a 398-square-foot addition to the southwestern side of the existing single-family residence on the subject parcel. The project would have negligible privacy impacts for neighbors to the north and south because living space within the existing homes on these neighboring parcels are situated uphill and east of the project. The neighboring properties to the west at 207 and 209 Arlington Avenue are located downhill from the site yet screened with various trees, and other vegetation, and the proposed addition and deck would not impact their privacy. Despite the request for a smaller rear yard, where required by the zoning district, the lower-level addition would remain out of view. The second story addition may be seen from the north facing windows of 212 Amherst; however, this is not a new configuration, given that the existing deck is already in place in the same location. Therefore, as proposed, the project minimizes privacy impacts upon surrounding neighbors.
7. Access to Light: The project will not have any impact on the natural light currently enjoyed by residences in the neighborhood as the orientation of the additions remain towards the rear and at a lower elevation, or remain facing the interior deck. Additionally, due to the position of the sun, the project would not cast shadows onto any surrounding properties.
In cumulative consideration of the above, the project provides reasonable protection to existing residences regarding views, design compatibility, parking, privacy and solar access.
Kensington Policy 4. When reviewing new development proposals, ensure views of scenic natural features (e.g., San Francisco Bay, distant mountains) and the developed environment (e.g., bridges, San Francisco skyline) are substantially preserved.
Generally, protected views in Kensington consist of western facing downslope views towards the San Francisco Bay and adjacent city skylines and distant mountains. Westerly (downslope) views from the project site are presently obscured by numerous mature trees existing on nearby parcels, and by those residences facing Arlington Avenue, substantially limiting the project’s potential to affect protected views in this direction. The addition or deck would not alter the views, given that the additions are primarily hidden from the public view, as they are on the lower level of the residence and facing the interior of the structure. Due to these established conditions, the project would not expectedly obscure existing views from adjacent homes to any significant degree
Kensington Policy 5. For new developments, encourage building scale, massing, architectural style, and materials to provide harmonious scale transitions and blend with the surrounding existing residential neighborhood.
The project does not have a significant impact in scale, massing and architectural style. The larger portion of the addition remains away from public view as it is located in the lower level and towards the rear of the home. This portion of the addition is then hidden with the small 88-square-foot addition of a rear deck. The second portion of the addition is facing the existing interior deck, and it is in part hidden by the garage. Overall, the project is keeping with the existing building massing and architectural style. The proposed additions are to match the existing residence and maintain the same aesthetic as the neighboring properties. Thus, the project is considered harmonious with the surrounding residential neighborhood in terms of building scale and design.
B. Consistency with Zoning: The subject property is located within the R-6 Single-Family Residential District (R-6), the Kensington Combining District (-K), and the Tree Obstruction of Views Combining District (-TOV).
Chapter 84-4 - R-6 Single-Family Residential District: Generally speaking, the intent of the R-6 Zoning District is to provide for orderly development of the single-family residential uses, accessory structures and the uses normally auxiliary to them. The proposed project is for the development of a 398-square-foot residential addition, and 88-square-foot deck addition. All components of the project are related to the single-family residence and are, therefore, uses permitted within the R-6 zoning district. The project also significantly complies with the height and setback requirements, and the parcel receives sliding scale, thus allowing a 5-foot side yard on both sides with an allowed aggregate side yard of 10 feet, which are both maintained. Therefore, the project is consistent with the R-6 Single-Family Residential District and remains consistent with the intended use.
The scope also includes a Variance request to allow a 5-foot 10-inch rear yard, where 15 feet is the minimum. In its current configuration, the subject residence already encroaches onto the rear yard (sitting at approximately 12 feet 4 inches); its footprint also covers most of the viable developable area. While the proposed addition does not fully comply with all the R-6 Standards, the request is justified due to the physical characteristics of the site. Due to the location of the residence, almost any type of expansion would trigger a variance request. The proposed additions utilize portions of the area facing the inner deck, and portions of the lower level and unconditioned space below to minimize the impacts on neighboring properties. Strict application of the R-6 district standards would unnecessarily restrict reasonable development of the parcel given its limits in terms of area and the slope. Additionally, despite the encroachment onto the rear yard, the proposed rear addition continues meeting the intent and purpose of the zoning district and meets the intent of the Kensington Combining District (as discussed in the section below). As a result, the variance request for the proposed rear addition does not compromise the intent of the regulation and does not create adverse impact to surrounding properties.
Chapter 84-74: Kensington Combining District: Section 84-74.802 of the County Code sets the gross floor area threshold standard for projects within the Kensington Combining District (-K). Projects that exceed the specific lot threshold require a Development Plan application and a public hearing. For a lot size of approximately 5,000 square feet, the gross floor area threshold standard is 2,500 square feet. The gross floor area for this project is proposed to be 3,131 square feet plus a 200-square-foot deck. The size of the residence is not excessive for the area as there are other residences in the vicinity that exceed 2,500 square feet; in fact the residences in the area range between 1,200 square feet to 4,200 square feet within the same street. The project will also not impose any limitations with respect to views, privacy and parking constraints on the adjacent lots.
The Kensington Combining District includes seven criteria for approval of the Development Plan. As detailed below, the project satisfies all seven criteria.
1. Recognizing the rights of property owners to improve the value and enjoyment of their property.
Finding: The project is to construct a 150-square-foot addition, and a 145-square-foot lower-level conversion (for a proposed accessory Dwelling Unit) and a 103-square-foot addition on the upper (main level), for a total of a 398-square-foot addition to the existing residence. The scope also includes 88-square-foot deck addition. All elements are typical requests for residential properties. Although the new gross floor area exceeds the gross floor area threshold for the subject parcel, the additions are not significant where they would decrease the value of the property or the neighborhood. The project will not be excessively larger or taller than other dwellings in the neighborhood and is designed to not deprive surrounding properties of views, privacy, natural light or parking. The additions and new deck will increase the value of the property as it allows the property owner more space to enjoy their lot and accommodate ordinary addition requests for residential uses.
2. Recognizing the rights of property owners of vacant lots to establish a residence that is compatible with the neighborhood in terms of bulk, scale, and design.
Finding: The subject parcel is not a vacant lot. Therefore, this criterion does not apply.
3. Minimizing impacts upon surrounding neighbors.
Finding: The project involves a residential addition that is mainly in conformance with all applicable development standards for the R-6 District. Seeking only a Variance request to the rear side. Section 84-74.204(b) of the Kensington Combining District Ordinance specifies that the ordinance is intended to promote the community’s values of preservation of views, light and solar access, privacy, parking, residential noise levels. The project is consistent with these values as discussed below:
- Views: The project would not result in adverse effects on views enjoyed from surrounding properties. The majority of the addition is located towards the rear of the residence and on the lower level (lower topography), while the other portion of the addition is facing the front while remaining behind the garage. Neither the lower addition nor the upper level addition affect the neighboring views given their location.
- Privacy: The project proposes a lower-level conversion and addition located at the rear of the lower level of the residence, and a separate addition facing the internal middle deck, and screened behind the existing garage. The overall proposal results in a 398-square-foot addition to the southwestern side of the existing single-family residence on the subject parcel. The project would have negligible privacy impacts for neighbors to the north and south given that the living space within the existing homes on these neighboring parcels are situated uphill and east of the project. The neighboring properties to the west at 207 and 209 Arlington Avenue are located downhill from the site yet screened with various trees and vegetation, and the proposed addition and deck would not impact their privacy. Despite the request for a smaller rear yard where required by the zoning district, the lower-level addition would remain out of view. The second story addition may be seen from the north facing windows of 212 Amherst; however, this is not a new configuration, given that the existing deck is already in place in the same location. Therefore, the project minimizes privacy impacts upon surrounding neighbors.
- Light and Solar Access: The potential for residential construction to limit light and solar access on neighboring properties are predominantly influenced by siting (i.e. setbacks), size, and height. The project does not alter the existing siting, nor does it significantly alter the size or height of the established building envelope. The project is adding livable space to the lower level of the residence and does not disrupt adjacent properties. The second story addition remains relatively hidden and towards the interior portion of the main level of the residence. The deck addition will also be facing the rear and does not interfere with light or solar access. Therefore, the project would have no impact on surrounding properties in terms of light and solar access.
4. Protecting the value and enjoyment of the neighbors' property.
Finding: As previously mentioned, the addition would not significantly block any views in the project neighborhood or decrease privacy or access to sunlight. Therefore, in the absence of significant impacts on neighboring parcels, the addition would preserve the value and enjoyment of the neighbors’ property.
5. Maintaining the community’s property values.
Finding: The project involves an addition to an existing single-family residence in an established residential neighborhood. The proposal does not involve an incompatible land use that would conflict with the surrounding residential community in a manner that may negatively affect property values. Additionally, the project does not substantially affect scenic views, privacy, or solar access for neighboring parcels to any significant degree. Therefore, the project maintains the community’s property values.
6. Maximizing the use of existing interior space.
Finding: The existing single-family residence consists of a main (second) floor at street level having approximately 1,614 square feet of living area, and a 699-square-foot lower (first) floor. The project is converting a portion of the existing usable unconditioned space on the lower level and doing an addition to this area for a proposed accessory dwelling unit. The other portion of the addition is located on the second floor (the main floor) and it remains within the building envelope. The project will provide additional living space and a new unit without significantly expanding the established building envelope, and the lower addition utilizes both the existing thereby maximizing the utility of first floor living areas.
7. Promoting the general welfare, public health, and safety.
Finding: The residential addition does not change the land use on the subject parcel and as described above, would have minimal impact on neighboring properties. The project’s compliance with applicable zoning standards and the requirement to obtain building permits will ensure that the addition does not present a hazard to public health and safety for the occupants or community at large. Thus, the project promotes the general welfare, public health, and safety of the Kensington community.
Chapter 816-2 - Tree Obstruction of Views: The -TOV Combining District furthers the Kensington Combining District’s goals, as its intent is to provide a method for property owners to gain restoration of views and sunlight lost due to tree growth by another property owner. The proposed development does not include any alteration, addition or removal of any trees. Therefore, the -TOV ordinance does not apply to the proposed project.
C. Appropriateness of Use: The project site is a lot with an existing residence within an established single-family residential neighborhood. The proposed addition will be consistent with the established use of the property as well as the guidelines of the Kensington area with respect to compatibility of the neighborhood. The proposed project will conform to the height and side yard restrictions of the R-6 zoning district, and despite the encroachment of the rear yard, the request is not one unusual for the area due to the restricting conditions of the lot size and topography. No portion of the project will infringe upon the existing views, natural light, privacy and parking of properties in the area. The proposed residence exceeds the maximum allowed gross floor area for the lot size however the bulk is not excessive for the area and development of the vacant lot will preserve property values of the surrounding area. Thus, the project is appropriate for the Kensington area and the R-6, -TOV, and -K zoning districts.
VIII. CONCLUSION
As proposed, the applicant requests approval of a Development Plan for a Kensington Design Review and Variance for the construction of a residential addition which would exceed the Gross Floor Area threshold. The proposed development is consistent with the Residential Medium Density (RM) General Plan land use designation, the specific policies of the Kensington area and complies with the intent and purpose of the Single-Family Residential (R-6), Kensington (-K) Combining District, and the Tree Obstruction of Views (-TOV) Combining Districts. Therefore, staff recommends that the Zoning Administrator approve County File #CDDP25-03032 based on the attached conditions of approval.
Attachments:
A. Findings and Conditions of Approval
B. Maps - Parcel Maps, Aerial Map, Zoning Map, General Plan Map
C. Agency Comments
D. Project Plans