Granny Units in Auburn, California

said on May 7th, 2012 filed under: Real Estate Nuts and Bolts, Water Wells, Septic Systems, Sewers, Electric Power

Put Granny in a pumpkin shell

And there you keep her, very well

Here, in bullet form, are the main rules for building a “granny” unit (or house, or flat) in Auburn, California, in fact, throughout Placer County, California.

Officially these units are known as  “secondary dwellings” and the rules are found in Placer County bulletin 17.56.200

The maximum floor area of the granny is based on the size of the lot:

less than 1 acre

  • 640 square feet

1 acre to 2.29 acres

  • 840 square feet

2.3 to 4.59 acres

  • 1,000 square feet

4.6 acres or more

  • 1,200 square feet

You can see that the maximum size for a granny is 1,200 square feet.  Period.  You can  put a granny unit  on a parcel smaller than 1 acre, but it must be attached to the primary unit or integrated within a detached accessory building, typically a garage.

The granny may be attached to garage as long as the granny has its own separate entrance.

You can add an additional 25% to the granny as a covered porch open on at least two sides.

The granny must be architecturally compatible with the primary residence.

Most grannies require two off-street parking spaces.

Either the primary property or the granny must be occupied by the owner of the property.  (Yeah, and how does anyone enforce this after the property has changed hands?  Deed restrictions, I guess, but probably not noticed unless a neighbor complains because both dwellings have been rented to “undesirables.”)

What is the main obstacle to adding a granny to an existing residence?  Poop.  That’s right, I said poop, or more specifically, getting rid of poop and other sewage which includes everything that you wash or flush down your drains.

If the property is already hooked up to a sewer line, you may find the permit process pretty easy.  Just tap into the existing line . . . and, of course, pay the county some more money, up front and on-going.

If the property is on it’s own septic system (septic tank, leach field and all that) you may have real problems.  In fact, you may be denied a permit.  Most of the time, homes are built with just enough septic capacity for the necessary original permit.  Such and such size septic tank, and such and so linear feet of leach line, plus enough approved space for a “repair field.”

Repair field?  This is suitable undeveloped space large enough to install another entire leach field if the original leach field fails.

If you add a granny, you are going to have to increase the capacity of the existing septic system, or (hold your breath) install an additional new septic system with it’s own tank, leach field and repair field.  This will require new percolation and mantle tests, a new septic system design, and installation.   Thousands of dollars.  How many thousands?  If you are very lucky, $10,000 to $12,000, but you better be ready to pay more.

Here’s the main point: 

If you are buying a home with the intent of adding a cozy little nest for granny, the very first thing you need to learn is whether you will be allowed to  obtain a septic/sewer permit for the second dwelling . . .  and how much that is going to cost you.  Learn this most vital fact before you close the transaction.





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