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Regulation 🙅‍♀️ Duplexes in older residential districts

Wisconsinplanner

Cyburbian
Messages
30
Points
2
My city will be amending our zoning ordinance to provide for stricter standards for infill development in our older residential districts. Currently these districts allow two family residential by right, with no restrictions other than lot size and area. Duplexes could be located on any lot and you could have an area that is entirely single family with uncompatible duplexes. We have been having problems with infill duplexes, such as not fitting the context of the surrounding development (e.g. side by side duplexes in area where 2 story homes are predominant, no windows on sides of the home, front doors on the side, etc.).

We are addressing some of these issues by compatibility requirements (for both single-family and two-family). Based on other ordinances, we are also considering requiring duplexes to be built on corner lots and each unit entrance to be located on each of the streets. This will limit the number of duplexes that could be built and give the appearance of single family homes from each of the streets. Does anyone else require stricter standards for duplexes, and if so, what?

Thanks for your input.
 

mgk920

Cyburbian
Messages
4,201
Points
26
Wisconsinplanner said:
My city will be amending our zoning ordinance to provide for stricter standards for infill development in our older residential districts. Currently these districts allow two family residential by right, with no restrictions other than lot size and area. Duplexes could be located on any lot and you could have an area that is entirely single family with uncompatible duplexes. We have been having problems with infill duplexes, such as not fitting the context of the surrounding development (e.g. side by side duplexes in area where 2 story homes are predominant, no windows on sides of the home, front doors on the side, etc.).

We are addressing some of these issues by compatibility requirements (for both single-family and two-family). Based on other ordinances, we are also considering requiring duplexes to be built on corner lots and each unit entrance to be located on each of the streets. This will limit the number of duplexes that could be built and give the appearance of single family homes from each of the streets. Does anyone else require stricter standards for duplexes, and if so, what?

Thanks for your input.

If you look at an historical map of Kenosha (and pretty much every other Midwest city), you will notice that these duplex-zoned residential areas coincide almost exactly with the limits of their respective urban development in 1945. These areas were developed as single-family and hastily converted to duplex to address a severe housing shortage caused by military personnel returning en-masse from WWII and needing places to live. Many of the existing single family houses were then quickly split into duplexes (ie, those with addresses like '530' and '530 1/2' or '530A'). That worked at that time, but in the decades since many became run down as they were sold and continued to be rented out by absentee landlords.

Over the 1990s, the City of Appleton aggressivly 'downzoned' the one-family used houses (including vacant lots?) in those 1945-era duplexed areas back to single-family, the impetus was from the single-family homeowners due to the higher street improvement assessment rates charged for properties used for 'commercial' purposes (defining 'commercial' here to include 2F and higher residential zones).

As for more specifics, I would contact the city offices.

Mike (not in city government, but following it closely)
 

Chet

Cyburbian Emeritus
Messages
10,589
Points
34
Muskego WI required all duplexes to have Plan Commission artchitectural approval. They also adopted a few design guides for their older neighborhoods, like this one .

PM me if you want more detail.
 

Gedunker

Moderating
Staff member
Moderator
Messages
11,909
Points
48
First, duplexes can be a positive thing, particularly if you can combine some first-time homeownership opportunities with them. In New England, I think they call it OOMF (Owner-Occupied Multi-Family) and it is quite common with the ubiquitous triple-deckers. (These were designed and built as multi-family one-over-one-over-one.) Owner occupancy removes one of the objections of multi-family -- the dreaded (and mostly rightly so) absentee landlord.

Our BZA has gotten tougher on the aesthetics sense. No more slabs -- full basement or crawl space minimally. Also, large windows on the public facades with a height:width ratio of at least 2.5:1. We prefer one-over-one double-hung sash as opposed to pseudo-colonial 9/9 with sandwich muntins. Where porches are prevalent, porches are required. Setback from front lot line equal to those in the vicinity. But, we discourage trying to disguise them as single-family.

Good luck with the code re-write.
 

Wisconsinplanner

Cyburbian
Messages
30
Points
2
Gedunker said:
First, duplexes can be a positive thing, particularly if you can combine some first-time homeownership opportunities with them. In New England, I think they call it OOMF (Owner-Occupied Multi-Family) and it is quite common with the ubiquitous triple-deckers. (These were designed and built as multi-family one-over-one-over-one.) Owner occupancy removes one of the objections of multi-family -- the dreaded (and mostly rightly so) absentee landlord.

Our BZA has gotten tougher on the aesthetics sense. No more slabs -- full basement or crawl space minimally. Also, large windows on the public facades with a height:width ratio of at least 2.5:1. We prefer one-over-one double-hung sash as opposed to pseudo-colonial 9/9 with sandwich muntins. Where porches are prevalent, porches are required. Setback from front lot line equal to those in the vicinity. But, we discourage trying to disguise them as single-family.

Good luck with the code re-write.

Owner occupancy is one of the problems that we historically have had with duplexes; therefore, the negative stigma that goes along with them. Most of the duplexes that are built here are strictly rental units that are built one after another by developers. Once one is done, they look for the next property that they can build another one. It would be difficult to require that all duplexes be owner-occupied, unless the City controlled the properties, so there still is the potential for absentee landlords.

We are building in some TND and compatibility principles into the older residential districts such as requiring windows on all sides of the home (including higher standards for street facing facades), requiring covered porches or stoops, requiring detached garages when this is the prevailing construction on surrounding properties, as well as matching adjacent setbacks (or reduced setbacks when an entire block is redeveloped or developed). These will cover both single-family and duplexes. New single-family homes and duplexes are also required to be compatible with surrounding development on three of five items. Compatibility options go into orientation on a lot, the visual size of the front facade, raised porches, building materials and roof slope and orientation.

Requiring a conditional use permit, such as suggested by Chet, is an option that we could explore. Requiring them to be upper/ lower flats, as historically constructed could be another option.
 
Messages
19
Points
1
side by side duplexes in area where 2 story homes are predominant
While the other contextual factors you mentioned are fair, I'd like to unpack this one in particular, because it seems not entirely on point. While two-story areas make two-flat/one-over-one forms feasible, at least in my fair city, side-by-side duplexes were still built in areas where the surrounding single family stock was two story as well. This likely had to do with the fact that it's easier to build a vertical fire wall than a fire-rated horizontal assembly as a vertical assembly can be made from basic masonry with little concern for penetrations (Home Depot parts will do), while the horizontal assembly in a two-flat will have numerous membrane penetrants in it that make firestopping much more of a chore, and wasn't easy to get right before Type X firecode drywall became a commodity.

Nowadays, there are other advantages to the side-by-side form as well: it provides improved visitability over a two-flat, even when built two-story, and with appropriate firewall construction, it can be used as a two-party building, where each half sits on its own lot and is independently owned, vs. requiring the use of condominium or tenancy structures. (One can view this as a trivial townhouse building, even.) The primary tradeoff is in lot width: as a result, side-by-side duplexes are more likely to be found in areas developed with more "squarish" platting patterns compared to their two-flat counterparts, which can fit onto narrow tract-house lots.
 
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