California allows "granny flats" in backyard of any single family house: would you build one?

A town can make a rule that the newly constructed ADU can’t be rented short term. Not sure about the main house.

What I’ve read is that (before this new law) the most common reason to build an ADU was for family, either older parents, adult children who can’t afford their own house, disabled children who can’t live independently, or as extra space for the family that lives in the main house. The next most common reason is AirBnB. Most people, as you say, don’t want to be landlords.

Then again, the high rents in high cost areas can make being a landlord more attractive. If you can rent out a unit for $3000 a month, which you certainly could in my area, that’s a lot of money.

Even if the ADU is for older parents or adult children, if those people would otherwise have lived independently, the ADU frees up a housing unit for someone else.

You can rent the house to one of your kids, at market value. Or rent the ADU to the kid, at market value. That makes it seem more fair.

This is an amazing little ADU. Accessible, good-looking, has decent storage for the size, even has washer and dryer, yet it’s only 294 sq ft. Bet it wasn’t cheap though.
https://www.inspiredindependence.com/65th-street/usq4jnjiyw55pqazmxe7xx7p1hphtd

The other projects on the same site are appealing too.

My fantasy ADU would be 100% off-grid solar, with a wall of Tesla batteries. CA requires solar on all new home construction, wonder if that applies to ADUs. I visited the Solar Decathlon several years ago in Irvine and those houses are ideal prototypes for ADUs. Here is a link to some of the homes from past competitions: https://www.solardecathlon.gov/past-where-now.html
I would also put in radiant floor heat and a rain collecting cistern system. If nothing else, such a home would be a good place to live after The Big One. It would be hard to build a mini dream home and then watch someone else move in though.

@“Cardinal Fang” here are a couple of thoughts - 1) I live in an area with one of the top 10 elementary schools in the state. I don’t think there are any apartment complexes in the school district. 1 bedroom rentals that are typically 700 square feet typically go for $2500-3000/month for rent newer units. I’m pretty sure rental demand would be quite high. 2) The other angle is that we both have aging mothers that we probably will need to take care of sooner or later. Both are quite independent. Mine is 90 now and we would have to do a lot of rearranging if she stays with us.

@ProfessorPlum168 You probably want to make your ADU accessible, then, if elderly parents are in the mix. Wider doorways with no threshold, grab bars, curbless shower with a bench, opportunity for bright lights, stuff like that Lots of people make their ADUs that way anyway, on the thought that they may want to move into the ADU themselves when the time comes, and leave the main house for children or renters.

It’s a lot easier to build in accessibility than to retrofit it.

I would consider it. I have a large lot (over 2 acres) and I could see building something that one of my kids could live in. I don’t think I’d want a random tenant. I’m not sure how it would work in my area as the CC and Rs prohibit renting of guest houses. I also wonder if the law would require the Homeowners association to allow people to rent out existing guest houses.
In my area short term rentals are pretty much prohibited so if someone wanted to build a ADU it would have to be long term rental or family. I think the law requires that the owner live in one of the units but I’m not 100% sure about that.

I’m not a lawyer. It looks to me like existing law, before this new spate of ADU laws, prohibited HOAs from imposing new restrictions on homeowners renting out ADUs; if a person buys a house planning to rent out an ADU long term, it looks to me like the HOA can’t then pass a rule banning it.

The new HOA regulations are vague. They say that an HOA can’t pass rules that make it effectively impossible to build ADUs, but can impose “reasonable” rules. According to the law, “‘Reasonable restrictions’ means restrictions that do not unreasonably increase the cost to construct, effectively prohibit the construction of, or extinguish the ability to otherwise construct, [an ADU or junior ADU].” I predict lawsuits.

The new laws are friendly to cities or HOAs banning Airbnb rentals.

Red flag warnings are up so I am thinking of fires. On streets that are too narrow, street parking is not permitted on those days so that fire trucks can access during red flag days. Where the extra units cars would park then could be problematic.

Our HOA also gives veto power to adjacent neighbors additions. Not sure if this will pass muster with the new law or not.

Presumably, the ADU occupants would do the same thing everyone else does, at times when street parking is not allowed: move their cars, if they have cars that they customarily park on the street. Parking scofflaws during red flag times ought to be dealt with, and I expect they would be, pour encourager les autres.

Are there a lot of narrow roads that need to be clear for fire trucks, that are also half a mile from a transit stop? Seems like ADUs on narrow rural roads would still be required to have parking.

I have relatives who live in the Oakland hills, where the streets are narrow and parking is extremely limited. More ADU’s up there would make things even scarier.

I couldn’t install one of those prefab units. I find them undesirable. I’d probably hire an architect to design something that would look similar to the main house with similar materials.

If you’re concerned about parking scofflaws, the answer is to crack down on parking scofflaws.

So you’re saying the Oakland police should prioritize parking in the Oakland Hills over more serious crime with an underfunded and undermanned police force? Or maybe you’re suggesting vigilante justice? Of course, I’m kidding.

The older streets are narrow like those in the Hollywood hills.
Parked cars on the street prevent fire trucks from getting through. Permitting houses with no offstreet parking just makes it more likely that cars may block fire engines. There is often just a few minutes warning of a wildfire.

New subdivisions are built so that streets are wide enough for two fire engines even with parked cars.

However, grandparents living in an ADU in their kid’s / grandkids’ back yard may decide to stop driving and sell their car, due to lack of need to drive due to accessibility of their relatives. That could be beneficial for many people, especially if their driving skills have deteriorated to marginal levels with respect to safety.

Most homeowners won’t build ADUs. Of those that do, most will have adequate parking, or the ADU will be used by non-drivers such as elderly parents or disabled family members. There will be some scofflaw drivers who live in ADUs and park every day illegally. Since the same car will be illegally parked every day in the same spot, those scofflaw drivers can fairly easily be dealt with at the parking authority’s leisure, ideally by subcontracting out to someone who will tow the offenders’ cars away and charge them lots of money to get it back. This does not seem like a major problem, to me.

Yeah the average house is either on a 6000-8000 sq foot lot which isn’t big enough for much else except for a shed/doghouse, or almost all newer developments which are on postage stamp lots.

Regarding @sushiritto concern about a prefab unit not matching the house - in the Bay Area, a good number of tract houses built in the 70’s and 80’s outside of the Peninsula and older cities were for the most part built pretty cheaply and quite frankly looked cheap. It wasn’t until all the IPO money coming in in the 90s that much more expensive developments were the norm. My house (built in ‘84) I would consider to maybe be a bit better that average standard, fairly cheaply built. If I was living in another state, I’d probably pay 4-6x less for that house than in the Bay Area. So I think a pre-fab ADU probably could be found that would match what I already have.

If you have a 5000 square foot lot, which is typical, and you’re allowed 4 foot setbacks side and rear, you very likely can find 500-600 square feet on your lot. Or you can convert your garage.

We have a 7000 or 7500 square foot lot. If we were inclined, we could build a studio unit over our carport (as some have done & rented it out), or take up most of the backyard with a ADU unit. We aren’t currently inclined to do either.