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Zoning 🟧 Accessory dwelling unit (ADU) ordinances - so called mother-in-law houses

Hawkeye66

Cyburbian
Messages
809
Points
30
If there is a better term for them, I am open to using it.

Do your cities have an ordinance that allows for smaller secondary housing units on a parcel in single family zoning areas?
 

mendelman

Unfrozen Caveman Planner
Staff member
Moderator
Messages
15,937
Points
60
Accessory Dwelling Unit (ADU)

We don't currently have such as ordinance, but when I've experienced it the regulations require the ADU be significantly smaller (max) than the principal dwelling unit on the lot.
 

luckless pedestrian

Super Moderator
Staff member
Moderator
Messages
13,620
Points
56
I have one and will PM it to you!

We allow them in our single family zones. It doesn't make sense to allow them in zones that allow multi family because if a 2 family is allowed, then you don't need an ADU; however if you make an ADU not subject to area/unit requirements if you have those, then you might want to allow an ADU in all residential zones.
 

Faust_Motel

Cyburbian
Messages
1,082
Points
39
We allow them, anywhere single family is allowed. 30-50% size of the primary (but at least 900SF is always allowed per state mandate) , must be an owner-occupied property, cannot be conveyed separately. Allowed on single-family properties in zone where multifamily is allowed. I
 

luckless pedestrian

Super Moderator
Staff member
Moderator
Messages
13,620
Points
56
We allow them, anywhere single family is allowed. 30-50% size of the primary (but at least 900SF is always allowed per state mandate) , must be an owner-occupied property, cannot be conveyed separately. Allowed on single-family properties in zone where multifamily is allowed. I
cannot be conveyed separately - I hadn't thought of that, hmmmm - I don't have that in mine
 

Hawkeye66

Cyburbian
Messages
809
Points
30
In my world that conveyance would trigger subdivision review and a whole host of other requirements.

-Oh- we also generally require a shared point of access for the primary and accessory.

Could you link us to your ordinance?
 

dw914er

Cyburbian
Messages
1,632
Points
22
ADUs, following California state housing law. That said, a new state law, SB9, is on the Governor's desk that may throw a wrinkle in how we permit units, allowing more units than just the ADU.
 

luckless pedestrian

Super Moderator
Staff member
Moderator
Messages
13,620
Points
56
In my world that conveyance would trigger subdivision review and a whole host of other requirements.

-Oh- we also generally require a shared point of access for the primary and accessory.

I don't required joint/shared access as we created the ordinance to not be just for a family member but to house anyone
 

NHPlanner

A shadow of my former self
Staff member
Moderator
Messages
10,156
Points
45
Permitted by administrative approval:


To increase housing alternatives while maintaining neighborhood aesthetics and quality, attached accessory dwelling units (ADU) are permitted on any property containing an owner-occupied single-family dwelling, provided that the applicant meets the criteria set forth below:

a) A maximum of one (1) ADU per property is permitted. An ADU shall not be permitted on property where more than one primary dwelling unit (PDU) currently exists;

b) The ADU is contained within or will be an addition to an existing or proposed single family detached dwelling;

c) Exterior alterations, enlargements, or extensions of the PDU are permitted in order to accommodate the ADU. However, no such change is permitted which would alter the appearance of the PDU to look like a duplex or any other multi-family structure (i.e., the house should not look like it was designed to house more than one family). The construction of any exterior accessways which are required for access to the ADU shall be located to the side or rear of the building whenever possible. The ADU shall also be designed to remain functionally dependent on the PDU and shall not have provisions for separate utilities, garages, driveways, and other similar amenities;

d) The ADU shall contain no more than two bedrooms;

e) The ADU shall not exceed 1,000 square feet in area;

f) The ADU shall be connected internally to the PDU. Internal connection shall mean the ADU shall share at least one common wall with the PDU, or be attached by a fully-enclosed breezeway that does not exceed 20 feet in length;

g) The property owner must occupy one of the two dwelling units;

h) One parking space for the ADU shall be provided in addition to any parking for the PDU;

i) The PDU, ADU, and lot shall not be converted to a condominium or any other form of legal ownership distinct from the ownership of the single family dwelling. In order to assure compliance with this requirement, the property owners at the time the ADU is established shall be required to execute a restrictive covenant running in favor of the Town, which shall be recorded in the XXXX County Registry of Deeds and a copy provided to the Community Development Department and the Assessor prior to the issuance of a Certificate of Occupancy; and

j) Where municipal sewer service is not provided, the septic system shall meet NH Water Supply and Pollution Control Division requirements for the combined system demand for total occupancy of the premises.

Permitted by conditional use permit:


Pursuant to the authority provided in RSA 674:21, the Planning Board may grant a Conditional Use Permit for Detached Accessory Dwelling Units (ADU’s) in the R District. The following criteria must be satisfied in order for the Planning Board to grant a Conditional Use Permit for a Detached ADU:

a) A maximum of one (1) ADU per property is permitted. An ADU shall not be permitted on property where more than one primary dwelling unit (PDU) currently exists;

b) The Detached ADU shall be located only in the side or rear yard of the property;

c) The Detached ADU shall not exceed 50% of the size of the Principal Dwelling Unit (PDU) or 1,000 square feet in size, whichever is smaller;

d) Lots seeking a Detached ADU shall be comprised of at least 125% of the minimum lot area as required by Section 3.02.A, Table 1;

e) A Detached ADU shall not contain more than two bedrooms;

f) The property owner must occupy one of the two dwelling units;

g) One parking space for the ADU shall be provided in addition to any parking for the PDU;

h) The PDU, ADU, and lot shall not be converted to a condominium or any other form of legal ownership distinct from the ownership of the single family dwelling. In order to assure compliance with this requirement, the property owners at the time the ADU is established shall be required to execute a restrictive covenant running in favor of the Town, which shall be recorded in the XXXX County Registry of Deeds and a copy provided to the Community Development Department and the Assessor prior to the issuance of a Certificate of Occupancy;

i) Where municipal sewer service is not provided, the septic system shall meet NH Water Supply and Pollution Control Division requirements for the combined system demand for total occupancy of the premises.
 

SlaveToTheGrind

Cyburbian
Messages
1,790
Points
32
State is mandating all cities adopt an ADU ordinance by November 1 if already not in their code. State code is using the term Internal Accessory Dwelling Unit.

In a previous city, we used the term Second Kitchen for a non-rental family only unit or MIL unit. Different building codes applied so the distinction was made.
 

the_girl

Member
Messages
57
Points
4
If there is a better term for them, I am open to using it.

Do your cities have an ordinance that allows for smaller secondary housing units on a parcel in single family zoning areas?
we just updated our ord and created the program in such a way that if you use our PreApproved plans they are issued over the counter
 

michaelskis

Cyburbian
Messages
21,216
Points
61
If there is a better term for them, I am open to using it.

Do your cities have an ordinance that allows for smaller secondary housing units on a parcel in single family zoning areas?
We allow Accessory Dwelling Units in all our residential zoning district by right subject to the conditioned square footage cannot exceed 30% of the conditioned square footage of the principal dwelling. The need to meet all the other requirements such as setbacks, height, lot coverage and such. They are also required to have one additional parking space.
 

arcplans

As Featured in "High Times"
Messages
6,791
Points
36
ADUs bro.. and I have an ordinance too.. but conforms to California state law. I also have completed a cool little handout that explains it.
I have one and will PM it to you!

We allow them in our single family zones. It doesn't make sense to allow them in zones that allow multi family because if a 2 family is allowed, then you don't need an ADU; however if you make an ADU not subject to area/unit requirements if you have those, then you might want to allow an ADU in all residential zones.
You should try to make that argument to California legislators :rofl:. They allow them in multi-family dwellings, including the conversion of parking and other spaces, and also in non-conforming units..sooooo ya, we don't plan anymore.
 

michaelskis

Cyburbian
Messages
21,216
Points
61
Why do you hate public transit????
Auto Unions Baby!

But in all seriousness, we had issues with inadequate regulations in the past (before I got here) and the street cross sections where not designed to accommodate on-street parking. Thus people parked there anyways and there were two situations were the fire truck and ambulance could not get down the street in time. We are a suburban community and we have a long way to go towards the establishment of urbanism and public transit, but with the new plans and regulations in place, it gives us a lot more options.
 

dw914er

Cyburbian
Messages
1,632
Points
22
ADUs bro.. and I have an ordinance too.. but conforms to California state law. I also have completed a cool little handout that explains it.

You should try to make that argument to California legislators :rofl:. They allow them in multi-family dwellings, including the conversion of parking and other spaces, and also in non-conforming units..sooooo ya, we don't plan anymore.

California's Multi-family ADU provisions are awful in terms of how its written and its land use implications.
 

rae.rae

Member
Messages
23
Points
2
I have one and will PM it to you!

We allow them in our single family zones. It doesn't make sense to allow them in zones that allow multi family because if a 2 family is allowed, then you don't need an ADU; however if you make an ADU not subject to area/unit requirements if you have those, then you might want to allow an ADU in all residential zones.
Could you PM it to me, too? We're in the middle of a code update and are planning to ask Council to allow ADUs, and I'd love to see what your city allows.

Will DM a link
Hi, would you be able to send me the link, too?
 
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