Nuts & Bolts of ADUs in Los Altos – Transcript 1 – ADU Law Changes

City of Los Altos, Guido Perspicone, discusses how to plan how to build and ADU in Los Altos 2020 at the LAAHA ADU event Feb. 27, 2020
City of Los Altos' Mr. Persicone presented the new State ADU laws and conducted informative Q&A
Written by lalahpolitico

Here is a lightly edited transcript of this event…On Feb.27, 2020  the Los Altos Affordable Housing Alliance held a public event in collaboration with the City of Los Altos Planning and Building Departments and with representatives of the local construction industry. About 200 people attended the presentations and participated in Q&A.

It’s easier to build an ADU now. But still involved. Learn about the process, the parking, the costs.

Youtube channel – LosAltosPolitico – hosts a video with clean audio of the entire 1 and half hour event. Links are in the article herein.

Herein is part 1 of the lightly edited event transcript. Part 1 is the presentation by the City of Los Altos Planning Services Manager Guido Perspicone.  He discusses the main provisions of the State laws that went into effect Jan. 1, 2020 and how they change ADU regulations in Los Altos. And there is also Q&A with the audience before the intermission.

Part 2 – to be released soon – is five panelists, Part 3 – to be released thereafter – is more Q&A.

On Feb.27, 2020  the Los Altos Affordable Housing Alliance held a public event in collaboration with the City of Los Altos Planning and Building Departments and with representatives of the local construction industry. About 200 people attended the presentations and participated in Q&A. Nuts & Bolts of ADUs in Los Altos.

It’s easier to build an ADU now. But still involved. Learn about the process, the parking, the costs.

Here is part 1 of the lightly edited event transcript. Part 1 is the presentation by the City of Los Altos Planning Services Manager Guido Perspicone.  He discusses the main provisions of the State laws that went into effect Jan. 1, 2020 and how they change ADU regulations in Los Altos. And there is also Q&A with the audience before the intermission.

Part 2 is five panelists, Part 3 is more Q&A.

Speakers during Part 1 … Who is talking….

Cathy Lazarus, Event Moderator, Community Volunteer, Los Altos Affordable Housing Alliance

Guido Persicone, Planning Services Manager, City of Los Altos

Jon Biggs, City of Los Altos – City of Los Altos Development Director

Dive into the Event Video

1:23 Guido Perspicone talks about State Law changes begins

8:06   Audience Q&A begins

Transcript part 1 – Law Changes and Q&A

Cathy Lazarus – Moderator

My name is Cathy Lazarus, and I’ve been asked by the Los Altos Affordable Housing Alliance, to be the moderator for this evening’s conversations about accessory dwelling units. It’s a rapidly changing field. And I bet that five years ago, most of us never even heard of an ADU or accessory dwelling unit. But the world has changed. And we’re trying to come up with solutions to increase the supply of affordable housing in our communities, to alleviate the housing crisis. So our objective tonight is to provide lots of different ideas and perspectives about the world of accessory dwelling units, but the situation is rapidly changing. To begin, I’d like to introduce our Planning Director from the City of Los Altos, Guido Periscone, who will give us an update on the new laws that took effect on January 1, 2020. So, with that, I’ll turn the mic over to Guido and let him give us an overview.

Causes of the Housing Shortage

Guido Persicone –

We’re going to go over some of the state law changes. As you can see, I titled the presentation “Accessory dwelling unit state law changes … For now.” Because these laws have changed significantly every year for the last three years. There have been changes to state law encouraging more and more development by us.

So just a little bit of my background and my credentials, I am a certified ICT planner. I have 16 years of urban Regional Planning experience. And this is my third time rewriting an ADU ordinance. Twice with the City of East Palo Alto.  And now, here. When I’m not here, I’m coaching my son’s baseball team. And those are my two beautiful kids [in the photo]. And my lovely wife and I live in South San Jose. And I’m very fortunate to have this opportunity to be working for Los Altos.

So how did we get here? There are a myriad of reasons in terms of how we got here. But the gist of the matter is we have a significant jobs to housing imbalance. Last year, within the last 12 months, there were approximately 55,000 jobs that were created in the greater Bay Area. And there were 7000 housing units that were built. And those numbers got replicated for each of the last eight or nine years.

Just to give some perspective, Anthony  – who’s in the back of the room – gave a presentation to the Downtown Collaborative. Look at the Santa Clara county’s GDP.  –  $35B.  If the county were scaled up to an average country, that would be $616B. That’s almost as much as the GDP of the state of Colorado. So we obviously are in a huge economic powerhouse with a significant jobs to housing imbalance.

Guido Persicone

Some of the State Bills affecting Los Altos

So how is the state responding? Here are just six of the bills affecting us. These got adopted within the last legislative cycle summer-fall 2019. In total since 2016, there have been approximately 12 bills adopted just related to us here in Los Altos, and there have been approximately 34 on housing overall.

We are trying our best to respond to those and eventually bring an ordinance to City Council. So I’m gonna go quickly through some of these bills, and then summarize in terms of where we are in terms of the current regulatory landscape.

SB13:  Impact fees cannot be assessed on units that are less than 750 square feet.

: ADUs can be counted towards the state’s RHNA number – given by the state of California – to meet our affordable housing goals. If a garage is converted, replacement parking cannot be required.

AB 68 Lot coverage and lot size cannot be used in terms of writing a city ADU ordinance. An ADU application must be approved within the 60 days of a completed application. Unless it’s part of the actual structure of the house, and lot coverage,  FAR,  open space and other design standards cannot prohibit at least a minimum of an 800 square foot a detached ADU.

AB 1670 The CCRs – if you’re live within an HOA – are void if they prohibit the development of ADUs.

AB 671 : The city must create a plan within the next housing element chapter of the General Plan to incentivize and promote ADUs. The Housing Element is the city’s long-term housing policies and goals that get adopted every five years by the City Council. We are in the next cycle by December 2022. The City has to have a housing element that’s certified by the state. And within that Housing Element plan, we must show how we’re promoting and incentivizing ADUs.


If you are on a single-family property, you’re allowed by right to have a detached 800 square foot ADU, and you are allowed by right to have a 500 square foot Junior ADU (JADU) within the confines of the existing house. There are no parking requirements for the Junior ADU.  There are no parking requirements for an ADU that fits within the existing carport or garage. No parking requirements for an ADU near transit or a part of the car share vehicle program.   Agents within the body of the existing house cannot be required to have separate [inaudible]. To summarize, just the lay of the land, you’ll see that there is a detached ADU and there is Junior ADU.  One each of those is allowed on every single-family lot and on multifamily properties that are zoned for residential. [MultiFamily may be allowed more.]


What if you have already maxed out your FAR on your lot?


If you have already maxed out your FAR or your lot coverage,  you’re still allowed to have at least an 800 square foot detached ADU. Or it could be an attached ADU.

The state bills go further and say if it’s a multi-family development – and here in Los Altos were defined in multifamily is having two or more units on a lot – you are allowed to have two detached at ADUS and 25% of the area within the existing structure can be for ADUs.

We will be recommending that the city council adopt this ordinance on an etch the sketch because it’s probably going to change in six months.

[Audience laughter.] So that will be part of our recommendation side.  Questions?

AUDIENCE QUESTION 2 – ADU MAX/MIN sq. ft 800 or 1200?

Hi. Last year, I thought there was some indication from the city that max ADU square footage is twelve hundred, not 800. Can you clarify that?


So the 1200 square foot is the max allowed by state law [and by the prior city ADU ordinance]. But now there’s a minimum that a City must allow which is 800 square foot detached unit. [or 800 attached.] So that’s the difference.


How can I know if I can build an ADU larger than 800?


We would have to work with you in terms of making sure you haven’t maxed out the overall lot coverage square footage. If you have, you would be limited to 800.

AUDIENCE QUESTION 3 – IMPACT FEES for over 750 sq. ft ADU?

I have two questions, One, when might the city adopt its new ordinance?

Two, what are the $ impact fees if you build over 750 square feet in Los Altos, attached or detached?


I don’t have the exact impact fees cut I can certainly get your info and we can calculate that.  The city does have an adopted master fee schedule, which shows all of the impact fees. I don’t have those numbers off the top of my head, but I can certainly get those for you. Second, in terms of ordinance adoption, on March 19 we’re hoping to go to the planning commission. And then onward to the second meeting in April for the first reading at the city council.

AUDIENCE QUESTION 4 – Do the Daylight plane & Separation rules apply?

So, if you’re looking to put up this 800 square foot ADU – which you are now permitted by right to have now – there are maybe a couple of other things which might be preventing you. Like the Los Altos Daylight Plane rule. And then there is the 10-foot structure separation Rule. So are these still the rules now?


So, AB 68 covers them. The cities still do have the right to regulate the setbacks and the height and whatnot. But you can’t do so in such a way that you will not allow someone to get an 800 square foot. So the daylight plane currently in the ordinance is void. And so that’ll be something if the city council wants to modify, that to be in conformance the state law, they’ll have to be open for discussion.

What about the 10-foot separation? The existing CITY ADU ordinance says that if you put up an ADU it has to be 10 feet from your house, and from any vertical structural member.  That includes things like arbors.  That rule definitely prohibits anything in my backyard. So, is that still effective?


So as of January 1, the City’s ADU ordinance is null and Void.  We have a legal opinion from our city attorney to that effect.  Therefore, If the 10-foot separation from your house is prohibiting the development of at least an 800 square foot at your property, we will have to modify that for you.

AUDIENCE QUESTION 5 – Natural Gas appliances allowed in ADU?

Did any of the state laws say anything about whether you can have gas appliances in an ADU? .


Good evening, I’m Jon Biggs the Community Development Director for the city of Los Altos. Right now our regulations do permit gas.  However, our Environmental Commission is developing a  ”reach code ordinance” which would require ALL electric appliances in any new construction. So the appliances, even the heating system would have to be done by an electronic appliance. [It will have to appear before Council and perhaps the Planning Commission, before becoming law.]

AUDIENCE QUESTION 5 – ADU vs. JADU difference?

Can you explain the difference between an Attached ADU and a JADU.


Attached ADU means merely that it’s attached to the house. The Junior ADU, according to the state legislation has to be within the confines of the house. It can be no more than 500 square feet. And there’s some other more technical stuff we can go into with you but that’s the general premise.

AUDIENCE QUESTION 6 – Garages /ADU /no parking replacement

Can an ADU be Attached to the side of the garage?




Can you convert a garage to ADU?


Yes, you can convert it. And the state specifically said if you convert that garage, the city can’t ask for replacement parking for the one or two garage stalls now gone.

AUDIENCE QUESTION 7 – 60-day ADU approval, really?

You said a junior ADU would be approved within 60 days. How about a regular ADU, what is your timeline?


Let me clarify that. So 60 days from a COMPLETED application, and very few customers have a completed application at first pass.  You know, we have very complex set of  building and other codes. So it 60 days from when you have a complete set of plans and all the application requirements fulfilled.


So if you convert a garage into an ADU, you get the parking exception. So If you convert the garage into a junior ADU, do you also get the parking exception? And is that within the confines of the house?


Then I’d have to research a little bit more and get back to you. The laws say the JADU must be within the confines of the house. Are all garages, even detached garages, considered to be within the confines of the house? I will get back to you.

AUDIENCE QUESTION 9 – Put a shed/ADU on the property line?

Right now, for example, you can put a shed close to a property line,  you wouldn’t be able to put an ADU right next to the property line.?  [Transcriber – correcting the audience member…New sheds can be no taller than 5 or 6ft. And with very limited square footage. Those kinds can be placed virtually at the property line. There are old, larger grandfathered sheds…]


No.  The state law says a minimum of four feet away from the side and rear property line. So you’re not going to be able to put a new one right on the property line. However, there’s a caveat. If you have an existing legally recognized accessory structure that has less than the  4 foot setback and you can prove to the city that that was built legally, then you can rebuild it right where it is.

AUDIENCE QUESTION 10 – ADU/JADU lot for coverage new construction

My question is about the Los Altos lot coverage. Can you explain? I have a client that wants to add on 700 square feet of family living area in the main house and wants to put a junior ADU attached to the existing house? And she also wants to add an ADU in the back in the rear of the property? That’s 500 square feet. How do you feel about that?


So this has come up a couple of times. Right now, people have asked this question. So it’s a little more of a nuanced answer. So the junior ADU has to be within the confines of the existing house. Now, the question came up, well, what happens if I add on to my property and then after the addition, apply for the junior ADU conversion, potentially that’s a possibility. But for now,  for that 700 square foot addition, that could not be the junior you because it’s not within the confines of the existing house. Okay?

AUDIENCE QUESTION 11 – new Garage addition first, later ADU convert?

Let’s assume that the existing garage is 400 square feet. Can somebody add 100 square feet to the garage and then [later] qualify to convert it to an ADU?


This is the same scenario as in the previous question when you add on to the property’s main house. So this question is can you add on to the garage as part of a junior ADU, and it’s the same scenario where I mean, you would have to… it has to be within the confines of the house. But once again, the question came up. Well, couldn’t I just add on to my house, get that finalized by the city, then go back and make it a junior at you. Theoretically? Yes.

AUDIENCE QUESTION 12 – Does a JADU need a bathroom & kitchen?

What is the requirement for a JADU? Does it have to have bathrooms? A Kitchen?.


Yes, legislators wrote that into the law. And for those who don’t have the hand up that we prepared …our planning department prepared it in terms of the requirements for the JADU. The maximum size is 500 square feet, it must have cooking facilities with appliances. There must be a deed restriction with the junior ADU indicating the property owner will live in one of the two units. So, these are some of the other restrictions, we have more provisions.


Can cities have a parking requirement for a new detached ADU and JADU?


So, the question was, can we impose a parking requirement – for a detached unit? And a JADU? The answer is yes. And then the questions –  Can spaces be covered or uncovered? So they actually wrote the answers into the law. You can have two independent parking spaces. They can be tandem which is basically back to back parking or parallel. They don’t have to be covered.

AUDIENCE QUESTION 12 – Neighbor has storage shed attached to the fence. Can I put my ADU next to the fence?


The minimum is 4 feet away…the ‘caveat case of an existing structure’ doesn’t apply to you because it had to have already been there, we had to have legally recognized it. It had to be in existence as of January 1, but that’s not the case in this scenario that you painted. Because the scenario that you painted was that you would be adding on.

AUDIENCE QUESTION 13 – PALO ALTO attached ADU needs own utilities

I have two clients in Palo Alto, one that did a junior ADU and one who did a full ADU. And the question that came up when doing so was the junior ADU was allowed/able to be connected to the primary residences, heating system, water, utilities. However, the full ADU not only had to have its own heating system, but it’s own water, heat, electric, as well as a firewall separation that separated the full attached ADU unit from the living space similar to as if you had multiple-unit housing. Is that a building department question? Or is that something that you have knowledge about?


I’m so glad you asked because Kirk, our building officials at the back so that might be a building official question. Please ask him during the roundtables afterward.

AUDIENCE QUESTION 14 – No parking for Garage Conversion…but gotchas?

Say I have a detached garage, when you convert that garage into an ADU…

You’re saying that the city does not require that you build a new one-space carport/garage when you convert your 400 square foot garage into an ADU? Am I right?

GUIDO PERSICONE  Yes. That is correct. But you actually brought up a really important point that needs to be addressed that, that even if the state says we can’t make you, even though don’t need to put in that replacement parking then, later on,  if you try to add on to the main house, now you’re in conflict with the parking requirements for the city. So it’s a little bit of a dance in terms of we’re trying to comply with state law, which says you can’t make you put in the replacement parking. But if you try to do something later down the road. There’s some conflict there.

AUDIENCE QUESTION 14b – Rear set back is just 4 feet, really?

 So I have a current setback of 25 to the rear, so with an attached ADU is that waived and it’s down to 4 feet?

GUIDO PERSICONE   So state law says you can have a four-foot setback for the Detached ADU.  For an Attached ADU, you would generally follow the [?side?] setbacks of the existing main house.

AUDIENCE QUESTION 15 – Single-family zone is now actually 3-family zone?

I have a question.  It appears that now every property LOT could be three family. Will Los Altos have any single-family zoning left?


That’s a question you’re going to have to take up with your State Assemblyman & State Senator. Being a city planner, we must enforce what the state gives us. So,  this is the crux of the matter. This is why there’s obviously a concern. Contact your state senator, because we’re basically just trying to implement the legislation adopted.


One, If you add on an 800 square foot ADU, for how long will that be exempt from the parking requirement…[the FAR/lot coverage city regulations]? Second, later can one then add on to the main house up to the FAR/lot coverage?


…so there are two questions there. So, I was addressing the potential scenario of ‘I have a detached garage in the back and I convert it. So now I don’t have the required parking as required by ordinance.’  That was the inconsistency there in terms of the FAR and are you going over what’s currently allowed, to go over for expanding your main house. Unless there’s a change in state law, that’s what will be implemented moving forward.

AUDIENCE QUESTION 15b – Do Flag lots have the same state rules?


I don’t know if I have fully thought this through. You need to build it on the main part of the lot in terms of FAR. We won’t county the flag part as part of the lot size. The setbacks and the height are in the state law.  At least where your building envelope is, you should be covered.

 AUDIENCE QUESTION 15c – Cost of City fees?

What are the permit fees for say a 500 sq ft. ADU? And one that’s 800 square feet?


I don’t have that off the top of my head. So, come into planning and I’ll look that up for you.

In general, there are planning fees, there are building fees. There are also — if you do choose to have separate utilities for the new unit — quite a myriad of different fees. So go google  ‘21 elements.’ It’s a group of planning directors for San Mateo County. They’ve actually created a calculator to figure out how much an ADU would cost generally within the region. And they actually break it down by different levels of construction in terms of quality and size. So, you can go to the 21 elements website to get a better calculator.

AUDIENCE QUESTION 16 – Illegal Structures Amnesty?

You may have come across this — some people have built illegal structures, structures that somebody is living in. What does the process of an amnesty program look like?


Legislators actually wrote into one of the laws that if you have an unpermitted structure, the city actually has to go through a process to work with the property owner to assess what part of the building really needs to be brought up to code.  One of the state laws says that there potentially could be up to a five-year deferment for certain building code and planning, violations that don’t meet the requirement. But that would be a process that we would undertake with the City building officials.  At the end of the day, our primary job is to keep the public safe. And so, we do not want to approve construction that puts the community or your family or your children in harm’s way.


So what about a basement for a detached ADU?


That basement square footage does have to be included in the 800 square feet. The current void City ordinance, which is null and void, does permit a basement. But that void ordinance did include the basement footage in the max.  So you could have 400 on top say, and 400 hundred in the basement.

AUDIENCE QUESTION 18 – JADU vs. rooms for rent?

If you have existing footage in your existing house, what’s the advantage of a JADU as opposed to just renting out a couple of the rooms in the house?


Well, no one stops you from renting rooms now, barring the City ordinance about no rentals for less than 30 days. You have that right as a property owner, but not short term rental. [no AirBnB]

AUDIENCE QUESTION 18 continued – JADU vs. rooms for rent?

What’s the advantage to the homeowner of calling it a JADU vs. a calling it a monthly rental?


Privacy. If you have a junior ADU as part of your house its’s walled off, it gives somebody privacy. It gives them the opportunity to have separate [basic] cooking facilities. If you have children come back from college or you have somebody who’s elderly and maybe needs a little bit of care — they still want their privacy. A JADU can be an opportunity for you to help serve your family and your family members.

AUDIENCE QUESTION 19 – Existing permitted ADU, non-conforming setback

I have an existing ADU that was permitted about 25 years ago. It has setbacks from property lines that are less than then the new numbers. Does that create any issues with permitting a remodel of it?


Well, so that’s a confluence of two of the state laws. First, we were talking about potential code violations and how we address that. So, is it less than four feet setback? [Yes]. And is it a legally recognized structure from the city’s perspective? [Yes].  There is one specific bill that I did not put on the slide deck.  We would need to ascertain what percentage of the ADU could be modified so that you’re not triggering City non-conforming ordinance. So that’s a little bit more of a detailed question…we can work with you on that.


Let’s have the city planners and city building employees in the back of the room stand up. We have a really awesome group here this evening. They are ready to answer some of your questions one on one during this break. They know the ordinances inside and out. And we have our chief building official here as well. So please ask them questions.

About the author


Norma Schroder is an economics & market researcher by trade and ardent independent journalist, photographer and videographer by avocation. Enthralled by the growth of the tech industry over the decades, she became fascinated with the business of local politics only in the past several years.