At the February 27, 2017 Sparks City Council meeting, Councilman Lawson asked the City Manager to look at shipping containers as an alternate means of construction. Councilman Lawson subsequently clarified to city staff that his question more specifically concerns possible limitations in the Sparks Municipal Code (SMC) that would limit or preclude construction of small residential units, including so called “tiny houses”, regardless of the building materials used.

Shipping containers are also known as metal cargo containers, steel cargo containers, shipping containers, freight containers, Conex boxes or sea vans. A shipping container is an industrial, standardized, re-usable portable vessel that was specifically manufactured for use in the packing, shipping, or transportation of goods and designed to be mounted on a rail car, truck or a ship. Employing used shipping containers as a building material for residential and commercial structures is relatively new to northern Nevada. A commercial project using shipping containers and known as The Eddy is currently under construction on Sierra Street in downtown Reno on a site adjacent to the Riverside Artists Lofts.

Also, relatively new to the region is interest in small residential units, including tiny houses. While there is no official definition of a tiny home, a distinction is often made between tiny (less than 400 square feet) and small (400-1,000 square feet) houses. However, for purposes of this staff report, the term “small residential units” is used to refer to both tiny and small houses. Growing concern about housing affordability in the Truckee Meadows has fueled interest in such homes as they potentially offer a lower cost and more ecologically friendly housing option. Small residential units are also being used as accessory dwelling units for aging relatives, adult children or house guests. A project in this vein is currently under construction on Ryland Street in Reno. It is comprised of 10 detached homes ranging in size from 650-684 square feet on a parcel .45 acres in size and branded as “Tiny Ten”; the website for the project indicates the homes are priced in the “low 200’s”.

Neither the use of shipping containers as a building material nor small residential units are specifically contemplated in the current SMC. Code amendments may be necessary if the City Council wishes to facilitate these types of projects. Building code changes may need to address mechanical, structural, and energy sections of the building code. Zoning code amendments may potentially include revised standards for the lot size, residential densities, building setbacks from property lines, landscaping, parking and architectural design.

City staff conducted an initial review of the SMC to identify possible impediments to utilizing shipping containers as a construction material and potential restrictions on construction of small residential units. The remainder of this staff report summarizes preliminary findings from the review.  Please note that the SMC provides for the possibility of permitting, on a case-by-case basis, deviations from the requirements of the zoning code through the Minor and Major Deviation processes. The Minor Deviation, which cannot be used for signs, allows for a deviation of up to 10 percent and can be approved administratively. The Major Deviation, which cannot be used for signs or parking requirements, allows for a deviation of up to 50 percent, and requires a public hearing by and approval of the Planning Commission.

USE OF SHIPPING CONTAINERS AS A BUILDING MATERIAL

The City’s Building Official relies on model codes, such as the International Building Code, developed by the International Code Council (ICC) and adopted by the City Council. The ICC has not yet approved model codes for the use of shipping containers or for small residential units. The Building Official anticipates the ICC will consider small residential units and the use of shipping containers as a building material later this year and that model codes may be available as early as 2018.  Once model codes are available the City Council could more readily amend various sections (e.g., mechanical, structural, energy) of the building code to facilitate such projects.

At present, the Building Official views shipping containers as an acceptable building material for construction – subject to the applicable residential, plumbing, electrical, mechanical, structural and energy conservation codes – of single family residences. Until a model code is available, the Building Official expects that use of shipping containers to construct single family homes will need to use the “alternative materials, designs and methods” approval process provided for in the building code.  The Building Official can accept such alternatives provided he can determine they are satisfactory, comply with the intent of the code and are at least the equivalent of what is prescribed in the code.

The Building Official does not, however, believe he could currently approve the use of shipping containers to construct multi-family structures or multi-tenant commercial buildings involving the stacking of shipping containers. A primary concern is the lack of a tested and approved fire-resistive floor-ceiling assembly (i.e., methods and materials to reduce the risk of fire spreading between the floor and ceiling of stacked containers). For this reason, the Building Official cannot yet determine whether an alternative method could be used to permit the use of shipping containers to construct multi-family residential or multi-level, multi-tenant commercial structures.

MINIMUM UNIT SIZE 

Both the building and zoning codes establish minimum sizes for residential units.  The city’s adopted building code requires residences to have a room with a minimum of 120 square feet of habitable space. When a second room such as a bathroom is added, the minimum size of the addition is 70 square feet for a total minimum size of 190 square feet. The zoning code is more restrictive as it requires residential projects to have an average unit size of at least 500 square feet.  This would, though, allow a ten-unit project to have, for example, five units that are 600 square feet in size and five units that are 400 square feet in size.

MINIMUM LOT/SITE SIZE

Minimum lot size can also constrain small residential unit development since, presumably, developers will want to reduce lot size for these homes. Minimum lot size ranges from 6,000 to 40,000 square feet in the city’s seven Residential Single-Family zoning districts. Smaller lots can be developed in clusters in these districts provided the maximum density allowed in that zoning district is not exceeded and the undeveloped portion of the subdivision is deed restricted as open or common space. In the four Residential Multi-Family zoning districts, the minimum site size is 6,000 square feet but multiple dwelling units may be developed on the site subject to complying with other applicable standards.  In the four Mixed-Use zoning districts, the minimum lot size is also 6,000 square feet but the City’s zoning administrator may waive this standard if a subdivision of at least five lots is created.

SETBACKS AND BUILDING SEPARATION REQUIREMENTS

A setback is the minimum distance between the property line, street right-of-way line, or edge of sidewalk to the nearest portion of the structure on a property. Setbacks may reduce the residential density that can be achieved by restricting the ability to develop the entirety of a parcel.

Setbacks vary by zoning district, as reflected in Table 1. Generally, the various Residential Single-Family districts require the greatest setbacks.  Multi-family districts have somewhat lesser setback requirements. The Mixed-Use districts, given their emphasis on flexibility and density, permit the smallest setbacks. To provide greater design flexibility in Single-Family districts, the zoning code allows for the required front and rear setbacks to be combined subject to maintaining minimum front setbacks of 7.5 feet and rear setbacks of 15 feet.

Table 1 – SMC Setbacks by Type of Zoning District

The City Council could reduce setback standards in the zoning code. Reduced setbacks could, however, trigger higher construction costs due to the need to comply with fire-related building separation requirements in the building code.  Current code requirements for the separation of buildings are summarized in Table 2.

Table 2 – Building Code Separation Requirements

MINIMUM AND MAXIMUM DENSITIES

The city’s Residential and Mixed-Use zoning districts include maximum, and in some districts, minimum, residential unit densities that could limit a developer’s ability to undertake small residential unit projects (see Table 3). Current maximum densities, particularly in the Residential Single-Family districts, would likely prevent small residential unit developers from achieving their desired yields. Conversely, the minimum densities in certain districts (e.g., 24 units per acre in parts of the Mixed-Use Commercial District) may be higher than a small residential unit project can achieve on individual lots.

Table 3 – SMC Minimum and Maximum Densities by Zoning District

MAXIMUM LOT/SITE COVERAGE

Lot coverage standards restrict the percentage a parcel can be covered by structure(s). In the SMC, lot coverage restrictions may impair small residential unit development in the Residential Single-Family zoning districts, the Residential Multi-Family district (MF2) with the lowest maximum density, and in one Mixed-Use district (RN).

PARKING

The zoning code requires one parking space per bedroom for single family detached dwellings and duplexes. Multi-family buildings, live/work dwellings and manufactured home parks are required to have one parking space per residence. Providing parking under current zoning code requirements may limit small residential unit development since the proportion of a site needed for parking is higher for such projects than for less dense development.

LANDSCAPING

The zoning code establishes minimum areas, expressed as a percentage of a lot or site, that must be landscaped. Meeting the current standards may be more difficult to achieve on small lots or sites in certain zoning districts. In the Multi-Family districts, 20 percent of the site must be landscaped.  In the Mixed-Use districts, 10-20 percent of the site area must be landscaped.    

INITIAL CONCLUSIONS REGARDING THE MOST APPROPRIATE ZONING DISTRICTS FOR SMALL RESIDENTIAL UNIT DEVELOPMENT

Staff anticipates possible developer interest in creating (a) subdivisions of detached small residential units (similar perhaps to the Tiny Ten project in Reno); and, (b) multi-family projects comprised of smaller units (i.e., averaging less than 500 per square feet) than currently permitted by the SMC.

Single-family developments comprised of small units would currently be allowed in certain parts of the Mixed-Use district by right (i.e., without a Conditional Use Permit or other process requiring Planning Commission approval) if they can meet the development standards for the zoning district. Multi-family projects comprised of very small units would also currently be permitted by right but for the requirement that the average size of the units in a development exceed 500 square feet. The City Council could facilitate both types of projects by amending the SMC, in a targeted manner, to address the various code requirements identified in this staff report.

The Mixed-Use districts are intended to accommodate the City’s more intense and dense land use designations. The Mixed-Use district is divided into four sub-districts: RN (Residential Neighborhood), MR (Mixed Residential), MUC (Mixed-Use Commercial) and DT/VS (Downtown/Victorian Square). A map identifying the Mixed-Use District has been attached to this report as Exhibit 1.

Outside the Mixed-Use districts, City staff foresee less demand for the use of shipping containers or development of small residential units due to both regulatory and market constraints. In the City’s Planned Developments, handbooks would have to be amended to permit the use of shipping containers as primary building material due to the very specific design most of the handbooks prescribe. Many handbooks have architectural standards and typologies of permitted residential units that would effectively preclude small unit residential development.

Should the City Council direct the City Manager to initiate code amendments for this type of housing the Council may wish to consider a workshop. A workshop could afford the City Council the opportunity to more fully articulate the goals, including specific objectives such as housing affordability and home ownership, the Council intends to advance through these code amendments.

Any amendment process would include coordination with other jurisdictions involved in approving the use of shipping containers and other options for construction of small residential units, as well as obtaining input from developers and other parties currently interested in this type of project.

The City Council may choose to direct the City Manager to prepare amendments to the SMC to facilitate the use of shipping containers and other options for construction of small residential units.

The City Council may choose not to direct the City Manager to prepare amendments to the SMC to facilitate the use of shipping containers and other options for construction of small residential units.

I move to direct the City Manager to initiate amendments to the Sparks Municipal Code to facilitate the use of shipping containers and other options for construction of small residential units.