Backyard Cottages & ADUs

Parent Q&A

  • Small shed in backyard, now Berkeley wants to call it habitable

    (4 replies)

    We built a shed with a deck off one corner in our yard last year under the requirements for appropriate shed size (under 120 Sq foot). We did not get it permitted because the code in Berkeley says if it is under that size and under 12 foot average height, you do not need to permit it. The shed was then painted with some windows and a large door. Now the city of Berkeley says we can't have a shed be "nonhabitable" if it has windows and a deck. They are considering it "habitable" because of this and want a building permit. There is nothing in the code that says this (if it has a deck or windows it is considered habitable) ANYWHERE. literally nothing. the shed is exactly that, something where our crap is stored, no one sleeps or stays in there, we do not rent it out, we do not spend time in it. But the city wants it permitted as a "habitable" structure because it looks nice and because there is a deck with windows. It is bogus. When we built it we asked all our adjacent neighbors if they were ok with it and everyone said yes.

    The shed will not stand up to building code, it is not built to live in! It would have to be completely remodeled for tens of thousands of dollars if we wanted to do that. Has anyone else dealt with this? We are at a loss. 

    Something is out of whack here. Windows do not make a shed habitable; many sheds have windows. Similarly, a deck does not need a permit if it is under 200 square feet and not attached to a dwelling. I assume your shed does not have any electricity or plumbing, so you need to document that for the City too. (If it does, then yes, unfortunately you needed a permit for it.) I also agree that it's likely that a neighbor called it in, so I'd be sure you are also compliant with any setback rules Berkeley has and reach out to neighbors who may be upset. Good luck!

    I'd send them a copy of their own building code and notate that there is nothing in the code about a shed having windows and deck around it, it must be permitted.  Seems unfortunate that the CoB is going to lengths like this to harass people who have tool sheds.

    Wish I were an attorney to give you a more concrete strategy, but like you said, this is bogus.

    Hi, I'm a GC in Berkeley, build outdoor structures, treehouses, some sheds, decks, etc. I don't know if I can help you right off, I've never heard of the building department (in berkeley or anywhere) come up with such requirements, ie no windows. If I may ask, how did they recome aware of the situation? If you don't know, it sounds like it could have been a neighbor complaining. I build treehouses with windows, as long as they're less than 120sf and not over 12 ft high, I don't worry about it. Very interested in knowing more.

    I am not sure who is telling you this since you didn't go through the permit process - an inspector making a spot house call? Weird, and that means yes one of your neighbors reported you. I would contact your councilmember's office for assistance, and include the code section that says under 120 sf is exempt.

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  • Pre-fab in law

    (1 reply)

    Does anyone have experience with installation of pre-fab units? We are interested in installing a unit in our yard with a studio and bathroom. Hoping someone has recommendations for a company or any other insight which would also be appreciated.

    RE: Pre-fab in law ()

    Hi, we asked a similar (ish) question on BPN several years ago, and someone responded that they had used a backyard shed (by I don't recall the company name) and hired a contractor to "upgrade" it, and liked it - you might look for that older question and replies. Would have been asking about ADU's, backyard cottages, or granny flats. 

    We've now started down that road, but are hiring a contractor to do a design/build for us (so not a fancy shed). Just at the beginning of the process, so no real insight to give. There are a couple of pretty high priced companies that specialize in the burgeoning ADU scene; we found one who charges less; the proof will be in the pudding of course once the unit is built. 

    I recall we found a company or two that specialized in the "prebuilt"; the name Summerwood comes to mind. But it was hard to figure out where we might see their models, visit an already-built structure, and determine whether savings would actually accrue by going prebuilt. We are happy to be using a design more of our choosing. At the time, googling prebuilt backyard cottages found quite a few options; fewer that worked in California 

    Best of luck in determining which way to go. You are joining LOTS of families doing the same thing in Berkeley now.  

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  • ADU / granny flat / backyard cottage in Berkeley: rent controlled?

    (3 replies)

    Hi, we're considering building a backyard cottage in Berkeley,  and are seeking information regarding if and how rent control might impact this decision. Does anyone know for sure?  We've heard all types of conflicting information, and can't get a response from the rent control board. Can anyone help?  Have you recently built and rented an ADU, and did anyone set limits on the rent you could charge?  Any recommendations for groups or organizations that can help new landlords?  Appreciate your thoughts, recommendations, and information. 

    I am working with a client on the same issue. It is my understanding that you will need to register the ADU with the rent board but it will not be under rent control regulation. You are not supposed to use it as an AirB&B or short-term rental but can charge any rent you want.

    New construction is exempt from rent control but no eviction control. You can't give the tenant 30 or 60 days notice to move without good cause, but you can raise the rent so high that they decide to move. Here is a list of "Partially Exempt" rentals:

    New construction must be COMPLETELY new, from the foundation to the roof. Do not convert a garage if you want to be able to raise the rent. In addition, you are free to charge whatever you want at the beginning of each tenancy. Rent control only applies to sitting tenants. 

    I suggest you join Berkeley Property Owners Association. You may also want to contact Michael St John for advice.

    When I looked into it in the last couple of years, ADUs in Berkeley are not rent controlled. There are a lot of requirements about who is allowed to build them and how they're built (off-street parking, set back from property lines, etc.), so definitely look into that. Also, the rent control board always seemed to respond pretty promptly to any questions we had. Have you tried calling them?

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Archived Q&A and Reviews


Have you researched or built a backyard cottage?

Jan 2014

Hi, we're considering building a backyard cottage (ADU), in Berkeley. This would be both an income-generating prospect (hopefully), and possibly a home for either the grown children, or a caretaker depending on how health goes. Have you done this recently? Which design/build (or other) company did you use? Seems like the one we hear most about is 'new avenue', but then we've also heard they were a spin-off from an original company, who we can't seem to find. Any company recommendations? I'd assume you had 3 bids, but again we're not finding multiple companies who do this.

I understand this can be a loaded question, but approx how much did you end up spending? (We're in Berkeley). Any recommendations for 'where to start' the process?

Thanks for any recommendations, advice, warnings, etc. Hopeful backyard cottage rental unit owners

I researched and built a backyard cottaage about 6 years ago. Strongly suggest first going to the planning office to learn what regulations you'll need to pay attention to. And find someone proficient in Berkeley rental law to understand that too.

After an architect took me to the cleaners (her fee almost 40% of the total project fee) I ended up getting a tuff shed garage and tricking it out on the interior. All told, $50K ish. Depends of course on your budget and what you're looking for.

The City of Berkeley was the most painful part of the entire thing - it was an endurance event of pain, waiting, obfuscation, and delays. Insane. Utterly. Loved my cottage in the end but the whole thing took years off my life. Good luck! Do your homework

First off, don't advertise that you expect to have income from the Cottage. It is easier to get approval for an 'In-Law Unit' than for a rental, or 'Secondary Unit', and sometimes neighbors can make life difficult if they think you are renting an 'In-Law'.

I have designed some ADU's and gotten them through the permitting process - others have built them. The last one cost around $135k, in 2009. It was about 400 sq. ft. Came out really nice, used by the grandma when she's in town, who is brave enough and agile enough to utilize the loft. The person who built it has moved on to bigger things, but I team up with Springwood Builders when I can.

I know this forum is not for us to talk up our businesses, but I also have some 'advice' that can be helpful to anyone who is considering this. I think the best way to start off is to go to the Planning Dept. with a sketch of the property with the approx. locations of the main house and the proposed cottage. You might be told by the planner that you can situate the cottage far back on the lot, b/c you are already getting a use permit. Careful on this, b/c it can lead to a requirement of automatic sprinklers, an expensive proposition. I could go on, but ...

I hope this helps. . Andus B

We used a company called Summerwood - highly recommend them. Great products, incredible customer service, great 'help' department. We built in Alameda and yes, planning department was the worst part of the experience. We also worked with an architect at first - he proposed us spending over $100k for about 400sf (which was $50k over budget). We purchased the 220 sf unit for about $11,000, and finished (electricity, sheetrock, lighting, painting, furnished came in around $18,000). The great thing about summerwood is you design the until - pick where the widows and door go, etc. We built what is typically a pool house but will tuck into a corner. We lived in our studio as much as the house, perhaps more. Its a great investment. good luck

Backyard Cottage/Tiny House - have you built one?

May 2012

Hi, We're considering building a 'Backyard Cottage' or 'Tiny House' in our backyard in the Berkeley flats. We're unsure how to proceed, and want to ask some locals about the pros and cons. We're thinking 400 sf or so, to use as a rental and/or when visitors come.

I understand that Berkeley is replete with such structures, and there's the one well-known one that got a lot of press last year (the UC Berkeley professor). But, have others built them recently? If you have, who did you get to do the construction, and did you buy a plan or have one firm do the design/build? What was the total cost, and what do you rent the cottage for? Would you recommend doing it? Pluses and minuses?

Thanks for any information, advice, recommendations, cautions... Hope to add small unit

Dear Hope-to-add-small-unit, I designed an In-Law Unit recently for a client in the flats of Berkeley. It is 450 square feet and cost about $130k, not including pre-construction costs. Eric Manou built it. In-Law Units are easier to permit than rentable units, which require a use permit with a public hearing, separate utilities, etc. I hope you enjoy the process.

I recently designed a small cottage in Alamo. It was 776 square feet and construction estimates came in at around $220K. You'll want to look at the zoning requirements for your lot and confirm setback distances and height limitations. You'll also want to look at parking requirements to determine if an additional parking space will be necessary. Lastly, talk to the city about permit fees for your project. The fees required for a project like this are often greater than clients expect.

I have to say that, in order to expand space potential for our tiny Albany house, we ordered up a backyard cottage from the Shed Shop in Fremont: This was probably nine years ago, but the cost came in at under $80,000, including the concrete slab foundation we put in, and the shed is still going strong. This was a one-room thing, however, with electricity and phone line. Not a mother-in-law unit. But worth looking at for extra space. spatially challenged

We went down the architect path for a small backyard cottage and it was a nightmare that cost us $7,000 in fees with nothing at the end as our $60,000 budget became an unfinished unit estimated at $110,000. Then we found Summerwood - and spent $12,000 for a 'pool cabana' that fit perfectly in the corner of our yard. It's 220 sq feet, and when you add Sheetrock, electricity, roof, lighting it was just about $20,000. We then re-did our yard and it all looked/s amazing - and was way, way better than the 400 sq foot planned structure. We could have easily added a sink, but for a toilet would have need to trench across the yard - do-able but we decided a second bathroom in the house made more sense. Happy to tell you details of our summerwood experience - amazing! No waste (all the wood is precut) - we love the windows and doors. Our house has been on a number of garden tours and people always ask about the structure. Love our cottage

Prefab backyard bungalow/cabin/in-law?

Jan 2011

Hello, We are considering the most inexpensive way to add a small 'bungalow' / cabin / in-law apartment to our Berkeley backyard. Has anyone used one of the pre- fab 'kits' for building such? Which company did you use, and how was it? How is it holding up? Other ideas for rather inexpensively adding a live-in 'apartment' to our backyard? Any recommendations/ suggestions welcome. Thank you! Need a little room

We had an estimate from an excellent contractor who specializes in prefab in law cottages. I have seen several that this contractor made and they were beautiful little homes. His price included all cabinetry and kitchen appliances. His name is Steve Vallejos and here's his email: Steve Vallejos stevevallejos [at] I can tell you more specifically if you want to call me: 529-6328. Micky

Not sure if this would meet your needs, but definitely worth checking out -- Tuff Shed. We built one several years ago to use as a workshop. Although ours is not plumbed or heated, I think you could add those things to the basic structure. Since it's on a slab, radiant heat would be ideal. We also added skylights (which are an option) and the space gets lots of natural light from them. We don't live in ours, but we know someone who does and it seems to work for him. Once you get all your permits in place, construction is super fast. Happy with Tuff Shed