The purpose of creating the residential mixed density zone (RMD) is to meet the stated goals of the comprehensive plan by allowing increased residential density to be integrated within single-family neighborhoods within the community.
The intent in the creation of this zone is to allow a creative mixture of housing styles and types. Development of this area should focus on maintaining the aesthetic quality of the city in general and the neighborhood in particular by providing for architectural diversity, adequate landscaping and open space. (Ord. 1292 § B(part), 2007).

Permitted uses in the residential mixed density zone are as follows:

A. Lots designated for use for other than single-family dwellings may not use the provisions for lot size reduction or lot averaging listed within Title 18 of this code.
B. Only one residential structure may be constructed per parcel; provided however, that more than one residential structure per parcel may be permitted for a mixed residential condominium development that meets all other provisions of LMC Chapter 19.16 and upon city approval of a binding site plan under Chapter 18.24 of the Lynden Municipal Code.
C. The minimum lot or parcel size for detached mixed residential condominium development within the RMD zone is one acre.
D. Detached units may be either site-built single-family dwellings or new manufactured homes as defined in Section 17.01.030 of the Lynden Municipal Code.
E. Mobile homes as defined in LMC Section 17.01.030 are prohibited. (Ord. 1292 § B(part), 2007).

Accessory permitted uses in the single-family zones are as follows:
A. Private garages. No detached garage or accessory building shall exceed one thousand square feet of inside floor area or ten percent of the lot area, whichever is greater; provided however, that the floor area of the accessory building does not exceed the floor area of the primary residence or three thousand square feet, whichever is greater;
B. Carports for no more than three vehicles, but only if the lot does not have garages;
C. Lots greater than or equal to ten thousand square feet may store up to two recreational vehicles on the lot; provided however, they are not stored in the front yard;
D. Tool shed, satellite dish, outdoor patios and outdoor fireplaces;
E. Mobile storage units or shipping containers are permitted for use during construction but must be removed within thirty days of final occupancy of the primary residence. No units greater than eight feet by ten feet are permitted in residential zones, other than during construction or for a period of up to thirty consecutive days within a six-month period to facilitate the moving in or moving out of a residence. Units eight feet by ten feet or smaller may be placed on a lot for not more than six months during any two-year period and must be located in the rear yard;
F. Private swimming pools, as provided in the International Building Code adopted pursuant to Chapter 15.02 of the Lynden Municipal Code and subject to LMC Section 19.37.090;
G. Accessory dwelling unit (ADU) on the following conditions:
1. Only one ADU per detached single-family residence. ADU’s are not permitted as part of any other housing type.
2. An ADU is limited to a maximum of six hundred square feet or forty percent of the square footage of the primary residence, whichever is smaller.
3. The ADU must be attached to the primary structure and must be of the same construction type as the primary structure.
4. Only one entrance for the entire primary structure and ADU combined shall be visible from the primary street. Additionally, there must be an interior door to access the ADU from the primary structure.
5. One parking space, in addition to those required for the single-family residence, will be required for the ADU.
6. No more than one bedroom shall be located within an ADU.
7. The primary residence or the ADU must be owner-occupied. A perpetual covenant against the property, approved by the planning department must be signed by the owner and recorded which specifies this requirement. (Ord. 1292 § B(part), 2007).

Secondary permitted uses in the residential mixed density zone are as follows:
A. Hobby shops, relating to the hobbies of the occupants of the home and not operated for production and sales purposes;
B. Greenhouses operated by the occupants, provided the products will not be offered for retail sale on the premises;
C. Home occupations. See Chapter 19.57;
D. Gardening and fruit growing not for commercial sale;
E. General farming, which does not include the commercial feeding of livestock, if the zoning lot is five acres or more in size and meets the requirements outlined in Chapter 19.39 of this code;
F. Family day care centers for up to eight individuals, not including the residents of the dwelling unit;
G. Parks and playgrounds;
H. Adult family homes and residential care facilities, up to six adults, when approved by the Washington State Department of Social and Health Services (DSHS). (Ord. 1292 § B(part), 2007).

The following property uses may be permitted in single-family zones by conditional use permit when recommended by the planning commission and approved by the city council. The conditional use permit may authorize height variations for public buildings, utility sub-stations, schools and churches.
A. Public buildings and utility sub-stations;
B. Club facilities that are directly related to home development such as community swimming pools, privately owned athletic facilities and other similar improvements directly related to residential areas;
C. Day care facilities for more than eight people with the maximum number of individuals to be determined as part of the conditional use permit process;
D. Churches, provided that the lot coverage does not exceed thirty-five percent, the front yard be landscaped and all other parking and landscaping requirements are met;
E. Schools;
F. Bed and breakfast establishments. (Refer to Section 19.49.030);
G. Manufactured home parks or subdivisions subject to the development objectives of the applicable sub-area plan. (Ord. 1292 § B(part), 2007).

A. For the purpose of this section, “net land area” means the gross acreage within a parcel minus all development requirements, designated critical areas and their buffers.
B. For the purpose of this section, properties that are separated from another single-family residential zone by an arterial street are not immediately adjoining said zone. (Ord. 1292 § B(part), 2007).

The following table and text provides regulations for height, area, setback and bulk requirements:

¹ For attached single-family units, the minimum side yard setback on the external wall is ten feet to living area.

A. All setbacks are measured from the property line to the furthest projection of the structure; including eaves. It is the property owner’s responsibility to have the property lines clearly marked for inspection.
B. On any lot, the minimum distance between the garage door and the property line or access easement parallel to the garage door must be twenty-five feet.
C. An attached garage may be built as close as five feet to the side property line provided the living area setbacks total twenty feet, from the furthest projection to the property line.
D. On corner lots, the side yard setback adjacent to the street must be a minimum of fifteen feet.
E. On corner lots, the primary pedestrian entrance to the building shall be from the designated front yard. However, the primary pedestrian entrance and address may be oriented to the designated side yard if both side yard setbacks are fifteen feet from property line to living area.
F. The side yard used for a driveway shall not be less than ten feet in width.
G. To be considered a “detached” structure, the minimum distance between two structures shall be six feet measured from foundation to foundation with no projections greater than eighteen inches.
H. A detached accessory structure, or tool shed may not be built closer than five feet to the side or rear property line including property lines abutting alleys. Accessory structures on corner lots shall not be permitted closer than fifteen feet to the side property line adjacent to the abutting street. The maximum height for all accessory structures shall be twelve feet, except for detached garages as noted below.
I. The maximum height of any detached garage that is serving as the primary garage shall be eighteen feet, provided however that the setback shall be a minimum of five feet from the rear and side property lines, the roof pitch and siding shall be consistent with the primary structure on the lot, there is no living space within the building and the height of the accessory building does not exceed the height of the primary structure.
J. The maximum height of any secondary garage or shop shall be eighteen feet, provided however that the structure is set behind the rear line of the house, the roof has a minimum 4:12 pitch, there is no living space within the building and the height of the building does not exceed the height of the primary structure.
K. The height of any building is measured from the approved average grade level as defined in Section 17.01.030 to the highest point of a structure; provided that appurtenances such as television antennas and chimneys are not considered part of the height.
L. On lots greater than ten thousand square feet in size, the height of a residential structure may be increased one foot for every two feet in increased setback distance beyond the minimum setback on both side yards and the front yard, to a maximum height increase of five feet, or total height of thirty-seven feet.
M. Uncovered wood decks and raised concrete patios not over twenty-four inches above grade at any point may be permitted within eighteen feet of the rear property line and five feet of the side property line. Deck privacy screening or fencing shall not be higher than eighty-four inches above the lowest grade. (Ord. 1292 § B(part), 2007).

All residential dwelling units must meet the following design criteria unless varied by the design review board as provided under Section 19.45.035:
A. All dwellings must be placed on a permanent foundation and the space between the foundation and the bottom of the home must be enclosed by concrete or approved concrete products.
B. All dwellings shall be oriented on the lot so that the primary pedestrian entrance faces the street or access easement.
C. The primary roof line must have a minimum of a 4:12 pitch. This is not applicable to re-roofing or additions to existing structures.
D. Roofing materials shall be wood shingle or shake, composition, asphalt laminate, clay or architectural metal. Exposed fastener corrugated metal or corrugated fiberglass roofing is not permitted.
E. Eaves and gable ends must be a minimum of twelve inches. This is not applicable to re-roofing or additions to existing structures.
F. The exterior of the home must be finished with a minimum of two types of materials. Exposed fastener metal siding is prohibited on residential buildings.
G. All units other than a detached single-family residence shall be subject to review and approval by the design review board.
H. No more than fifty percent of the lineal frontage of the building elevation may be occupied by garage doors. For the purposes of this section, a set of garage doors serves one dwelling unit and means one double garage door or two single garage doors separated by less than five feet.
I. Only one set of garage doors may face the street unless the garage doors are setback from the living area a minimum of ten feet.
J. All parking requirements of LMC Section 19.51.040 must be met on site. (Ord. 1292 § B(part), 2007).

Chapter 18.14 of the Lynden Municipal Code provides minimum plat design requirements. In addition to those requirements, the following are specific design recommendations intended to improve the aesthetic design of the subdivision as a whole. The items below are not meant to be exhaustive and developers are encouraged to incorporate other creative design elements within the project.
A. It is desirous that lot sizes and lot frontage widths are included and intermixed in the design of the subdivision to provide more street interest and potential for varying house designs.
B. Curvilinear streets with connectivity are encouraged to provide a varied approach to the housing units. (Ord. 1292 § B(part), 2007).

See Chapter 19.63.
(Ord. 1292 § B(part), 2007).

A. Front yards shall be used for ornamental purposes only. No storage sheds, portable storage tents, temporary canopies or other similar structures may be located within the front yard; provided however that portable canopies or tent structures may be used during events or yard sales, but must be removed within seventy-two hours of the sale or other event.
B. No fences, growth or other obstruction over three feet in height above the curb grade shall be allowed within the clear vision triangle, as defined at LMC Section 17.01.030.
C. Front yard setbacks may not be used for the storage of boats, campers, or any recreational vehicle. (Refer to Section 19.31.020(B).) (Ord. 1292 § B(part), 2007).