There have been 96 housing units — the equivalent of a good-sized subdivision — built or started on small parcels during the last four years located in an area what could best be described as the City of Manteca circa 1970.

They run the gamut from auxiliary dwelling units — ADUs also referred to as granny flats — and replacing older homes on larger lots with duplexes or small apartment complexes to a cluster of 20 half-plex units.

That in addition to several replacement homes that eliminated older, smaller, and structurally questionable houses.

There are even more projects approved — or in the review process — on larger parcels that are surrounded by existing development that could add another 149 apartments and townhouses.

The latest is a plan to replace a house on a large parcel at 429 Sutter Street across from St. Anthony’s Catholic School with a  6-unit apartment complex known as Sarene Place.

And if you toss in the empty fields immediately west, to the northwest and the north and northeast from Kaiser Hospital, there are another 607 apartment units and half-plexes that have been approved.

While the Kaiser area projects that are primarily along the future extension of Center Street may not meet the definition of infill projects for some given it is wide open space, the fact that is in area that has been developed for more than 35 years means it piggybacks to a degree on existing infrastructure in the older city via simple extension projects.

The infill trend has been gaining momentum as housing prices, the cost of development, and rents have steadily increased.

It also helps that the City of Manteca has enacted an infill incentive program that reduces impact fees for residential and commercial development within a defined area of the central city and nearby neighborhoods.

And now that the city is moving toward increasing allowed height limits in commercial mixed use, business industrial park, and commercial neighborhood  zones from 45 to 75 feet as well as going from 45 to 55 feet to allow four stories in R-3 high density zone designed for apartments, the trend toward more development within the established core of the city is expected to accelerate.

“We are certainly pleased that infill development is picking up,” noted Community Development Department Deputy Director Lea Simvoulakis. “ Vacant infill sites are often blighted, creating a nuisances in the community, while contributing very little property tax revenue.  Developing these infill sites removes a potential eyesore and blighted property and also improves value to the City and community by providing housing and/or commercial use.”

Fueling the trend besides growth is the fact vacant land and parcels that are under-utilized with existing housing pencil out in the changing market to be viable projects.

Infill housing is also closer to shopping, restaurants, services, often schools, and public transportation than newer tract developments.

Much of the central district consists of what planners call “walkable” neighborhoods.

The new homes — free-standing, duplexes, and apartment units — command higher rent and selling prices but they are still below the average cost by 10 to 20 percent of projects in newer section of the city.

The driving force behind that is the fact the basic infrastructure is already in place — sewer, water and storm main  lines, streets, and even phone, cable, electric, and natural gas service.

Not having to extend trunk lines and such to serve a new housing unit thanks to the infrastructure backbone being in place helps reduce construction costs upfront.

At the same time adding additional housing units (ADUs) on existing lots that is feasible in much of central Manteca as well as on many lots developed after 2000 south of the120 Bypass can be done at a lower cost in terms of impact fees.

Impact fees can add tens of thousands of dollars to the cost of building a house.

There are several impact fees that are not collected in Manteca on auxiliary dwelling units 750 square feet or less in a bid to encourage more ADUs.  

That helps ADU projects pencil out.

And if the ADU is 500 square feet or less the builder is also exempted from paying school impact fees to further reduce development costs.

There have been 58 ADUs built or started in the last four years. That includes six apiece in 2020 and 2021, 27 in 2022, and 19 so far this year

The ADU is allowed to have a maximum square footage of 850 square feet in a studio-style layout, a maximum of 1,000 square feet for a one bedroom dwelling or 1,200 square feet  for a handicapped accessible home.

They cannot be higher than 16 feet.

No additional off-street parking will be required for an ADU. They also must have an independent exterior entrance.

There was a time when so-called “granny flats” — small secondary dwelling units accessed from paved alleys or behind existing homes — provided Manteca with a supply of affordable housing.

They lost popularity as tract development took over and many cities made then virtually impossible to build.

The current state movement that requires allowing garages conversions done to code, ADUs being built whether they are free-standing or added to and existing house, and allowing the conversion of single family homes into multiple family residences are all aimed at squeezing the most out of existing developed areas to help address California’s chronic housing shortage.

ADUs must be allowed in all zoning districts where residential uses are permitted. Local discretion for location of ADUs may be based only on the adequacy of water and sewer services, traffic circulation, and public safety considerations.

The dwelling units may be rented separately from the primary residence but may not be sold or otherwise conveyed separately from the primary residence.

 To contact Dennis Wyatt, email dwyatt@mantecabulletin.com