It is the intent of this chapter to provide opportunity for greater flexibility in zoning and design requirements, encourage a variety of housing types, encourage infilling of skipped-over parcels in developed areas of the city and to provide for maximum efficiency in the layout of streets, utility networks and other public improvements.
(Ord. 995 § 12 (Exh. A), 2015; Ord. 1095 § 1 (Exh. A), 2023; Ord. 1124 § 2 (Att.), 2025)
A planned residential development encourages imaginative design and the creation of permanent open space by preserving or creating environmental amenities superior to those generally found in conventional developments, and by preserving to the greatest possible extent the natural characteristics of the land, including topography, natural vegetation, waterways, and views. For single-family residential developments, the inclusion of a variety of housing types such as duplexes or townhomes may qualify for density bonuses listed below.
A. 
Density Bonus. The city may approve an increase in the dwelling unit density up to:
1. 
In the low-density district, 15 percent, rounded to the nearest whole number.
2. 
In the moderate-density district, 20 percent, rounded to the nearest whole number.
3. 
In the high-density district, 25 percent, rounded to the nearest whole number.
B. 
Subdivision Requirements. A planned residential development shall be exempt from the specific design requirements of a standard subdivision, except that when any parcel of land in a planned residential development is intended for individual ownership, sale, or public dedication, procedural and applicable state laws pertaining to the subdivision and conveyance of land and the preparation of maps shall be followed.
C. 
Relationship of Planned Residential Development Site to Adjacent Areas. The design of a planned residential development shall take into account the relationship of the site to the surrounding areas. The perimeter of the planned residential development shall be designed to minimize undesirable impact of the planned residential development on adjacent properties and, conversely, to minimize undesirable impact of adjacent land use and development characteristics on the planned residential development.
D. 
Buildings may have common walls and, therefore, be built to the property line as in townhouse construction. Wherever buildings are separated, a minimum distance of 10 feet shall be maintained between such buildings.
E. 
Landscaping. Natural landscape features which are to be preserved, such as existing trees, drainage ways, rock outcroppings, etc., may be accepted as part of the landscaping plan when such natural features contribute to the attractiveness of the proposed development.
F. 
Additional requirements are required for planned residential developments. Reference YMC § 18.10.120(G) and Chapter 18.16 YMC.
(Ord. 995 § 12 (Exh. A), 2015; Ord. 1057 § 9, 2019; Ord. 1095 § 1 (Exh. A), 2023; Ord. 1124 § 2 (Att.), 2025)
A mixed use development encourages imaginative design and the creation of open space in development by preserving or creating environmental amenities superior to those generally found in conventional developments and preserves to the greatest possible extent the natural characteristics of the land, encourages development of affordable housing, and establishes a method for utilizing potential zoned properties.
A. 
Standards.
1. 
Uses shall be allowed as indicated under Chapters 18.35, 18.36, 18.37, and 18.38 YMC, except that automobile service stations and drive-through facilities shall be prohibited.
2. 
At least 20 percent of the combined gross floor area of the buildings proposed on the site shall be devoted to residential uses, and at least 20 percent to nonresidential uses. Parking garages or portions of garages devoted to residential or nonresidential uses may be counted towards this requirement, but surface parking may not.
3. 
Land uses in mixed use sites shall be selected and designed to encourage interaction among uses. Examples include but are not limited to commercial developments which are significantly used for shopping by on-site or adjacent residents or office workers.
4. 
At least 30 percent of the commercial component must be constructed prior to completion of the residential component, providing that adequate infrastructure is constructed for the remaining commercial component.
5. 
The residential component of the mixed use development shall be composed of multifamily units.
B. 
Density Standards.
1. 
A minimum average density of 16 dwelling units per acre is required.
2. 
There is no maximum density.
C. 
Mixed Use Site Area.
1. 
Lots may contain more than one use and will be a shape, size and design appropriate to the zone and intended uses as determined by the city.
2. 
A minimum of 50 percent of the lineal street front of the ground floor of mixed use buildings along arterial or collector streets shall be devoted to commercial or office uses. Parking garages devoted in whole or part to commercial or office uses may be counted towards this requirement, but surface parking may not. Mixed use buildings along lesser classification streets shall not face this requirement.
D. 
Exemptions From Certain Provisions. A mixed use development shall be exempt from the specific design requirements of a standard subdivision, except that when any parcel of land in a mixed use development is intended for individual ownership, sale, or public dedication, procedural and applicable state laws pertaining to the subdivision and conveyance of land and the preparation of maps shall be followed.
E. 
Relationship to Adjacent Areas.
1. 
The design of the mixed use development shall take into account the relationship of the site to the surrounding areas. The perimeter of the mixed use development shall be so designed as to minimize undesirable impact of the mixed use development on adjacent properties and, conversely, to minimize undesirable impact of adjacent land use and development characteristics of the mixed use development.
2. 
Setbacks from the property line of the mixed use development area shall be comparable to or compatible with those of the existing development of adjacent properties or, if adjacent properties are undeveloped, the type of development which may reasonably be expected on such properties given the existing zoning of such properties and the land use component of the comprehensive plan.
F. 
Additional requirements are required for mixed use developments per YMC § 18.10.120(G) and Chapter 18.16 YMC.
(Ord. 995 § 12 (Exh. A), 2015; Ord. 1095 § 1 (Exh. A), 2023; Ord. 1124 § 2 (Att.), 2025)
It is the intent of this section to provide for the development of townhouses within residential neighborhoods which may be conveyed as individually owned, separately platted lots. A townhouse is a one-family dwelling unit which is part of a group of two or more such units separated by common party walls having no doors, windows or other provisions for human passage or visibility through the common walls. Each one-dwelling unit in a townhouse is attached by not more than two party walls.
A. 
Density Standards and Uses.
1. 
Density Bonus. The city may approve an increase in the dwelling unit density up to:
a. 
In the low-density district, 15 percent, rounded to the nearest whole number.
b. 
In the moderate-density district, 20 percent, rounded to the nearest whole number.
c. 
In the high-density district, 25 percent, rounded to the nearest whole number.
2. 
No more than four abutting townhouses or townhouse clusters within the townhouse project site shall have a common front building setback. Variations in the setback of front building faces shall be at least four feet.
3. 
No townhouse dwelling unit shall be located closer than 25 feet to any public right-of-way nor within 15 feet of a private drive, access road or common open parking area to the front or rear of such a dwelling unit.
4. 
Every lot containing a townhouse must provide each unit private space of at least 200 square feet, oriented to either the building front, rear and/or side, enclosed visually by fences or walls at least five feet in height or plantings to screen first level views from adjacent units. This space can include porches, patios and decks.
5. 
The minimum side yard requirement for end dwelling units in townhouse groups shall be the same as the underlying zone. For all dwelling units other than end dwelling units in subdivided townhouse developments, the common walls shall be designed with zero lot lines.
6. 
No portion of a townhouse, accessory structure or other building type in or related to one group or cluster of contiguous townhouses shall be nearer than 10 feet to any portion of a townhouse or accessory structure of another townhouse building or cluster.
7. 
When the only driveway is from the street, each pair of units must share a common curb cut.
8. 
Conversion of existing structures to a townhouse project will be permitted provided all townhouse development standards as outlined in this section can be satisfied.
(Ord. 995 § 12 (Exh. A), 2015; Ord. 1057 § 10, 2019; Ord. 1124 § 2 (Att.), 2025)
It is the intent of this section to permit the location of manufactured homes as a permanent form of dwelling unit, to provide standards for the development and use of manufactured homes, and to make a distinction between manufactured home communities and manufactured home subdivisions and their characteristics.
A. 
Manufactured housing units shall comply with the following requirements:
1. 
Homes shall be set below grade on ribbon-footings and a permanent foundation shall be constructed around the perimeter. No more than 12 inches of the perimeter foundation shall be visible or above the finish grade of the lot.
2. 
Manufactured housing shall be comparable to site-built housing in the neighborhood within the same zoning district. In general, manufactured homes shall be comprised of at least two fully enclosed parallel sections with a total width of at least 24 feet and a length of at least 36 feet.
3. 
The age of a manufactured home, as reflected on the title, shall not exceed a maximum of five years at the time of installation.
B. 
Manufactured housing communities shall comply with the following requirements:
1. 
The minimum lot size for a manufactured housing community shall not be less than three acres, nor more than 15 acres.
2. 
Yard setbacks along the perimeter of the property shall be 15 feet from the required buffer.
3. 
The minimum lot size and width shall be 4,000 square foot lot size average, a minimum 40 feet wide and 80 feet deep.
4. 
A 10-foot dense sight barrier landscape buffer and six-foot solid wood fence shall be required around the perimeter of the site. The buffer shall be placed along the perimeter property line and the six-foot solid wood fence shall be placed 10 feet inside the perimeter property line.
5. 
Each manufactured home site shall have access from an interior drive or roadway only.
6. 
Access to the manufactured housing community shall be limited to not more than one driveway from a public street or road for each 200 feet of frontage.
7. 
In addition to the parking requirements of Chapter 18.54 YMC, a minimum seven-foot parking on each side of the street or minimum seven-foot parking on one side of the street and a parking area for guests of at least one space for each five homes. Parking areas shall be located in a centralized location(s).
8. 
No manufactured housing community shall be constructed to block connecting streets shown or proposed as part of the Yelm comprehensive plan.
9. 
All interior private streets of the community shall have minimum 11-foot drive lanes.
10. 
Manufactured home communities shall connect with traffic and pedestrian ways on all abutting or connecting streets.
11. 
All streets, roads and driveways shall be paved to a standard of construction acceptable to the public works department. Interior pedestrian walkways, carports and parking areas shall be paved.
12. 
A minimum four-foot internal walkway shall connect each space with common areas, internal roads, public streets and parking areas. All walkways must be separated, raised, or protected from vehicular traffic and provide access for handicapped persons.
13. 
Accessory buildings or structures accessory to the manufactured housing community as a whole, and intended for the use of all manufactured home occupants, are permitted, provided the building area not exceed one-fourth of the common open space area.
(Ord. 995 § 12 (Exh. A), 2015; Ord. 1124 § 2 (Att.), 2025)