Chapter 18.14
MDR MEDIUM DENSITY RESIDENTIAL ZONE DISTRICT
Sections:
18.14.050 Development standards.
18.14.070 Screening and buffering requirements.
18.14.010 Intent.
The intent of the MDR medium density residential zone district is to:
A. Provide for a high standard of development for residential areas of medium density including both middle and multifamily housing;
B. Provide designated areas in which a minimum net density of ten units per acre and a maximum net density of nineteen units per acre with the potential maximum net density of twenty four units per acre if permanently affordable dwelling units are included to promote the efficient use of land;
C. Guide medium density residential development in such a manner as to encourage and plan for the availability of public services and community facilities such as utilities, police and fire protection, streets, public transit, schools, parks, and recreation;
D. Encourage development of attractive residential areas that provide a sense of community, establish a pedestrian-friendly atmosphere, and contain a variety of housing types;
E. Ensure that development without municipal utilities is at a density and in a configuration that enables cost-effective urban density infill development when municipal utilities become available.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O95-035, Added, 12/19/1995)
18.14.020 Permitted uses.
Permitted uses in the MDR medium density residential zone district are as follows:
A. Single-family detached dwellings which were legally established prior to April 15, 2021;
B. Duplexes;
C. Triplexes;
D. Quadplexes;
E. Stacked flats;
F. Townhouses;
G. Multifamily dwellings;
H. Cottage housing;
I. Co-living housing;
J. Designated manufactured homes on single lots of record, and in designated manufactured home parks, in accordance with the provisions of TMC Chapter 18.48;
K. Designated manufactured home parks;
L. Senior housing facilities, independent;
M. Parks, trails, open space areas, and recreational facilities;
N. Support facilities;
O. Planned unit developments;
P. Family child care home; child mini-day care center, subject to TMC Chapter 18.52;
Q. Adult family homes, residential care facilities;
R. Any combination of the permitted uses listed in this section may be combined on one site, in accordance with the provisions of TMC 18.14.050;
S. Attached wireless communication facilities, except that it is prohibited to attach a nonaccessory wireless communication antenna on a single-family detached or middle housing dwelling;*
T. Bed and breakfasts;
U. Agriculture uses up to thirty acres in size which were established prior to January 1, 2011, subject to TMC 18.42.070;
V. Community gardens;
W. The housing, care and keeping of animals consistent with the requirements of TMC Chapter 6.08;
X. Wildlife refuges and forest preserves;
Y. Permanent supportive housing, subject to TMC 18.42.150;
Z. Transitional housing, subject to TMC 18.42.150.
*Wireless communication facilities are subject to Federal Aviation Administration (FAA) standards and approval, and furthermore are subject to provisions for wireless communication facilities in TMC Chapter 11.20, Wireless Communication Facilities.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O2022-006, Amended, 08/01/2022; Ord. O2021-019, Amended, 01/18/2022; Ord. O2020-005, Amended, 03/16/2021; Ord. O2020-003, Amended, 09/15/2020; Ord. O2018-025, Amended, 12/18/2018; Ord. O2017-006, Amended, 07/18/2017; Ord. O2010-029, Amended, 06/07/2011; Ord. O2011-002, Amended, 03/01/2011; Ord. O2010-005, Amended, 09/07/2010; Ord. O2005-011, Amended, 07/05/2005; Ord. O2001-012, Amended, 03/19/2002; Ord. O2000-004, Amended, 07/18/2000; Ord. O97-019, Amended, 06/17/1997; Ord. O95-035, Added, 12/19/1995)
18.14.030 Accessory uses.
Accessory uses in the MDR medium density residential zone district are as follows:
A. Storage sheds, toolsheds, greenhouses;
B. Private parking garages or carports;
C. Home occupations, subject to TMC 18.42.030;
D. Noncommercial recreational structures, which could include but are not limited to swimming pools and recreational ball courts;
E. Energy systems;
F. Accessory dwelling units, in accordance with the provisions of TMC 18.42.010;
G. Co-living housing;
H. Neighborhood community center;
I. Accessory wireless communication antenna;*
J. Electric vehicle infrastructure;
K. Supportive housing facilities such as emergency housing, emergency shelters, permanent supportive housing, and transitional housing are permitted as an accessory use only as part of a permitted church use. Such supportive housing facilities shall not exceed twenty percent of the total building square footage of a church use and are subject to the requirements of TMC 18.42.150.
*Emergency communication towers and antennas and wireless communication facilities are subject to Federal Aviation Administration (FAA) standards and approval, and furthermore both uses are subject to provisions for wireless communication facilities in TMC Chapter 11.20, Wireless Communication Facilities.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O2021-019, Amended, 01/18/2022; Ord. O2018-025, Amended, 12/18/2018; Ord. O2010-029, Amended, 06/07/2011; Ord. O2011-002, Amended, 03/01/2011; Ord. O2010-015, Amended, 09/07/2010; Ord. O97-019, Amended, 06/17/1997; Ord. O96-022, Amended, 12/17/1996; Ord. O95-035, Added, 12/19/1995)
18.14.040 Conditional uses.
Conditional uses in the MDR medium density residential zone district are as follows:
A. Churches;
B. Wireless communication towers;*
C. Cemeteries;
D. Child day care center;
E. Schools;
F. Neighborhood community center as a primary use;
G. Neighborhood-oriented commercial center;
H. Private clubs and lodges;
I. Medical clinics or hospitals;
J. The following essential public facilities:
1. Emergency communications towers and antennas;*
2. Mental health facilities (including but not limited to congregate care facilities; adult residential treatment facilities; evaluation and treatment centers);
3. Inpatient facilities including substance abuse facilities (including but not limited to: intensive inpatient facilities; long-term residential drug treatment facilities; recovery house facilities);
K. Group foster homes;
L. Recreational vehicle parks;
M. Senior housing facilities, assisted;
N. Temporary expansions of schools, such as portable classrooms.
*Emergency communication towers and antennas and wireless communication facilities are subject to Federal Aviation Administration (FAA) standards and approval, and furthermore both uses are subject to provisions for wireless communication facilities in TMC Chapter 11.20, Wireless Communication Facilities.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O2020-005, Amended, 03/16/2021; Ord. O2018-025, Amended, 12/18/2018; Ord. O2017-006, Amended, 07/18/2017; Ord. O2000-004, Amended, 07/18/2000; Ord. O97-019, Amended, 06/17/1997; Ord. O96-022, Amended, 12/17/1996; Ord. O95-035, Added, 12/19/1995)
18.14.050 Development standards.
Development in the MDR medium density residential zone district must meet the following requirements:
A. Site Area. All residential developments must meet the following density requirements:
1. Minimum: ten dwelling units per acre;
2. Maximum: nineteen dwelling units per acre. The purchase of transfer of development rights in accordance with TMC Chapter 18.57 would allow a maximum density of twenty dwelling units per acre. Projects that provide two permanently affordable housing units in the MDR medium density residential zone district would be allowed an increase of one additional dwelling unit above the maximum current density of nineteen dwelling units per acre up to a maximum increase in density of five dwellings unit per acre. This would create a new maximum density of twenty-four dwelling units per acre in the MDR medium density residential zone district for projects providing permanently affordable housing units. Projects providing permanently affordable housing units by this method would have to be part of a new multifamily housing project that provides ten or more dwelling units and meet the requirements of TMC 18.42.140.
B. Density Calculation. The calculation of the density requirements in subsection A of this section is based on the portion of the site devoted to residential and associated uses (e.g., dwelling units; private community clubs; open space; stormwater detention, treatment and infiltration). The following land is excluded from density calculations:
1. Land that is required to be set aside for public use as open space, right-of-way, or land on which development is prohibited by TMC Title 16, Environment, and land that is to be used for private roads. Provided, that portion of park and open space areas that consists of stormwater facilities and that is designed for active and/or passive recreational purposes in accordance with the drainage design and erosion control manual for Tumwater shall not be excluded from density calculations;
2. Land that is intended for future phases of development created in accordance with TMC 18.14.060;
3. Land that consists of lots devoted to uses other than residential and associated uses, including but not limited to churches, schools, and support facilities (except for stormwater detention, treatment, and infiltration facilities).
C. Division of Land Not on Public Sanitary Sewer. Division of land in areas without sewer must occur in a manner that maintains long-term potential to achieve minimum required densities and efficient provision of sewer once sewer becomes available. For a proposed division of land not required to be served by the extension of public sewer at the time of approval, a conversion plan shall be submitted in accordance with TMC 18.14.060 for the entire property, and the proposed land division shall be subject to the following:
1. For land division of an existing lot of record created prior to September 15, 1998:
a. Any division creating two lots shall not be subject to the minimum density requirements of subsection A of this section, provided one of the lots created is at least five acres in size. A note must be included on the recorded land division that future land divisions shall meet minimum density requirements of subsection A of this section in each phase of development.
b. Any division creating more than two lots shall meet the minimum density requirements of subsection A of this section in each phase of development.
D. Dwelling Unit Allowance.
1. Density on individual lots in the MDR medium density residential zone district can be exceeded to meet the dwelling unit allowance as follows:
a. Allow up to two dwelling units per lot.
b. Allow up to four dwelling units per lot if at least one dwelling unit on the lot is permanently affordable housing that meets the requirements of subsection (D)(6) of this section.
2. Two accessory dwelling units are allowed on all principal lots and are subject to the same regulations as a principal unit.
3. Accessory dwelling units count towards the dwelling unit allowance.
4. The standards of subsection D of this section do not apply to lots less than one thousand square feet.
5. A sleeping unit in co-living housing is calculated as one-quarter of a dwelling unit for purposes of calculating density.
6. To qualify for additional units under the affordable housing provisions of subsection (D)(1)(b) of this section, the required number of affordable housing dwelling units shall meet the permanently affordable housing standards in TMC 18.42.170.
E. Lot coverage, maximum impervious surface: seventy percent of total area of the lot.
F. Structure height: forty feet, maximum; provided, however, that no structure shall penetrate imaginary airspace surfaces as defined by 14 C.F.R. Part 77. A map that provides detailed information on ground and imaginary airspace surface elevations is available for inspection in the community development department.
G. Yards.*
1. Front: ten feet minimum from frontage property line.
a. Driveways in front yards of any dwelling units must be a minimum of eighteen feet in length as measured along the shortest edge of the driveway starting from the front property line.
2. Side: five feet from property line, minimum; provided, that side yards may be reduced to zero where the number of lots created is equal to the unit density allowance in subsection D of this section or where a townhouse is attached to another townhouse.
3. Rear: five feet from property line, minimum.
Where any structures or portions of structures, except for single-family detached dwellings, are adjacent to the RSR residential/sensitive resource and LDR low density residential zone districts, the minimum setback shall be twenty feet.
H. Yards Exception. Any side or rear yard, not abutting on a public or private street, may be reduced to zero; provided:
1. That the yard area reduced by this procedure is added to the required setback on the opposite side of the site;
2. The opposite side yard setback is no less than ten feet after the yard area has been added as described in subsection (G)(1) of this section;
3. Where zero yard setback is used, the abutting site must be held under the same ownership at the time of initial construction or the owners of the abutting property(ies) record agreements or deed restrictions providing maintenance access and consent in writing to such zero yard setback;
4. The adjacent setback for such abutting property(ies) is not less than ten feet.
I. Park and Open Space Area. New development in this zone district shall set aside land for park and open space area as specified in TMC 17.12.210 and 18.42.130 and the citywide design guidelines.
*See Diagram 18.04.670, Yard Determination Diagram, in TMC 18.04.230, Y definitions.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O2020-005, Amended, 03/16/2021; Ord. O2020-015, Amended, 02/16/2021; Ord. O2018-007, Amended, 10/16/2018; Ord. O2016-037, Amended, 01/03/2017; Ord. O2011-002, Amended, 03/01/2011; Ord. O2008-017, Amended, 10/21/2008; Ord. O2004-009, Amended, 12/07/2004; Ord. O2000-004, Amended, 07/18/2000; Ord. O98-009, Amended, 10/20/1998; Ord. O98-001, Amended, 09/15/1998; Ord. O97-027, Amended, 03/03/1998; Ord. O97-024, Amended, 03/03/1998; Ord. O96-021, Amended, 12/02/1997; Ord. O96-022, Amended, 12/17/1996; Ord. O95-035, Added, 12/19/1995)
18.14.060 Conversion plans.
A. For any land division that is submitted in phases of development, and for any development where sewer is not available or that does not meet the minimum density requirements of TMC 18.14.050(A), the approval shall be contingent upon the following:
1. The lots created by the land division for residential and associated uses (e.g., dwelling units; private community clubs and recreation areas; stormwater detention, treatment and infiltration) shall meet the applicable requirements of TMC 18.14.050.
2. A conversion plan must be submitted for the entire property which demonstrates that the property can be subsequently subdivided to create sufficient lots to achieve the minimum densities necessary to comply with TMC 18.14.050. Such conversion plan shall depict a schematic lot layout, approximate location of utility easements, and potential street access and an internal circulation system consistent with city transportation policies. Conversion plans shall not be required to be stamped by an engineer or surveyor, and may be included as part of a drawing or plan submitted for the land division application. Simultaneous with the filing of the conversion plan, the applicant will be required to record with the county auditor, in a form acceptable to the city attorney, a document to be placed in the chain of title of the property giving constructive notice of the special density requirements relating to the property. This conversion plan will not bind future phases of development of the site to anything except the obligation to meet the overall density requirements of the entire property. Acceptance of a conversion plan by the city or county does not, by itself, constitute approval of, nor the granting of vested rights to, a future phase of development.
(Note: The purpose of the conversion plan is to ensure that the entire property can be ultimately developed at the residential densities required for this zone district, not to limit future development to a specified development scheme. Recognizing that some property subject to this requirement may not be redeveloped in the near future, the time and cost involved in preparing and obtaining approval of a conversion plan should be kept to a minimum.)
B. A permit to construct any single-family detached dwelling on a lot of record that is greater than one acre in size shall be contingent on the submission of a conversion plan which demonstrates that the remainder of the lot may be subsequently subdivided to create sufficient lots to achieve the minimum densities necessary to comply with TMC 18.14.050. Such conversion plan shall meet all of the provisions of subsection (A)(2) of this section.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O98-001, Amended, 09/15/1998; Ord. O95-035, Added, 12/19/1995)
18.14.070 Screening and buffering requirements.
Buffering should be provided between this zone district and areas in the LI light industrial zone district. Buffering should be equally shared between the abutting industrial and residential developments, unless one of the uses is already developed as of January 1, 1996. If the residential use already exists, no further buffering should be required of the residential property owner. If the industrial use already exists, the residential use will be required to install buffering measures as outlined in TMC Chapter 18.47.
(Ord. O2025-011, Amended, 12/16/2025; Ord. O97-024, Amended, 03/03/1998; Ord. O95-035, Added, 12/19/1995)