My second ADU project in the Bay Area (why and how?)

My second ADU project in the Bay Area (why and how?)

Rental Property Investor · Santa Clara, CA · Member since 2019 · 160 posts · 156 votes

Hi everyone,

I've got tremendous help and support from this forum in the past 3 years. To give back to this community, I thought I'd share information on the second ADU project I'm working on in Santa Clara. I posted about my first ADU project in San Jose back in 2019 and shared 3D visual, pictures and numbers if you are interested: https://www.biggerpockets.com/...

Building an ADU could be a daunting task and takes a lot of $$ and effort. So why is ADU a good idea? 

The short answer: strong cash flow and immediate equity creation! It's been almost 2 years since my ADU project in San Jose was completed. I not only found (and kept) amazing tenants but also took out a home equity loan (through Figure.com) from the San Jose property at really good rates (whole process took 5 business days from application to money in my bank). Thanks to the red hot housing market, I was able to take out $250k, $50k more than the initial $200k that I invested into the San Jose ADU project. I'm planning on using the $250k home equity loan towards my second ADU project in Santa Clara.

In fact, I realized that as long as I can create strong cash flow for each of my ADU projects, I can just rinse and repeat this process - invest the equity created from the last ADU project into building the next ADU. If done right, the rents from the last ADU would more than cover the home equity loan monthly payments + increased property tax.

A little more about the Santa Clara ADU project I'm working on now:

With the experience from the first project, this time around I'm more confident about who I should work with, budget, timeline, what kind of tenants and rents I'm able to get, and of course things to watch out for. In addition, California loosened the ADU regulations at the beginning of 2020. All bay area cities reduced fees, and made it easier for homeowners to build larger ADUs, which also made my decision easier.

This time, I'm building a 2B1B 1200 sqft detached ADU in Santa Clara. The reason I designed a 2B1B instead of a 2B2B is that Santa Clara only allows 1 bathroom maximum at this time. However, I do expect the codes to relax overtime, so my architect designed a large walk in closet for one of the bedrooms that could be potentially convert into a bathroom in the event that Santa Clara allows a 2nd bathroom for ADUs in the future. Here's the floor plan if you are interested:

I budgeted about $400k total for this project. Will see if I can pull this off.

Other factors taken into account:

1. Time horizon. I'm a buy-and-hold investor and I'm planning on holding on the property for decades, so instead of immediate resale value (which ADU doesn't compare very well with perhaps other rehab/flip projects), I care much more about long-term cash flow and long-term resale value. In the long-term, I think SFH with ADUs will sell very well because I do believe multi-generational living will be more and more common with 1) more immigrants moving to the bay area with their elderly parents and 2) baby boomers starting to take care of their elderly parents who need long-term care. Demographics are in favor of ADUs for sure. Also, who doesn't like additional rental income to help with the mortgage payments? But the ADU design needs to take these various scenarios into account and create enough separation/privacy between the 2 households living on the same lot.

2. Rental market in the bay area. When the pandemic first hit in 2020, I wasn't very sure about building ADU since everyone started working from home and the bay area rental market was suffering as more people moved to cheaper places. However, since the vaccine rollout started, I saw more and more people moving back to the bay, and I'm confident most tech companies in the bay area are going to adopt a hybrid working model instead of a 100% remote model, which still requires people to live close to the offices/campuses.

3. Cost of construction is going up every year (raw materials, labor, fees, etc.). So if you are contemplating on building an ADU, it doesn't hurt to start planning early. To me, the earlier I can start and finish the project, the lower the building cost will be and the earlier I can achieve better cash flow. Each day of delay is $$ lost.

4. Effort and commitment. It IS hard work to build an ADU and it will take roughly a year from planning to finding tenants, but once it's done, you will benefit from the hard work for decades. So you want to make sure you are mentally prepared for the hard work going in and are committed to see it through. It will be a very gratifying process. Because of the large investment and high stakes, don't underestimate the importance of choosing the right designer & contractor to work with. You want experienced experts that can guide you through the process, not someone who adds additional stress to the whole process.


Lastly, happy to answer any questions. Would love to connect with you if you are also building ADUs in the Bay Area.

Cheers,

Chen

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Dan H.Pro Member
Investor · Poway, CA · Member since 2015 · 7k+ posts · 8k+ votes
5y
Originally posted by @Chen Zhou:
Originally posted by @Hai G.:

Thanks for sharing, Chen. Curious what kind of rent are you foreseeing for the new ADU build? Are you doing it for long term rental purposes?

I recently completed an ADU build (attached ADU) in one of my properties. While the return is good with that one the prospect has gotten worse with plummeting rent in the Bay Area and higher build cost that I'm not sure if I would build another one. Curious about your thoughts.

Congrats! Do you mind sharing the numbers for the attached ADU?

I had the same dilemma last year, but now want to build my second ADU ASAP. for the following reasons:
- I think the pandemic actually makes ADUs better/more attractive options than apartment complexes. If designed well, you are talking about renters getting SFH like experiences with a private yard. If you make your ADU a premium unit/super cute, you can attract high quality renters who will stay longer.

- Also building cost is only getting higher in the future, so it's better to lock in lower price/property tax now than to wait further.

- Overtime, the math will continue to get better as rents go up over time. 

Chen

What makes you believe building costs are not coming down?  The price of plywood is up almost 300% in the last year.  There are a few reasons, but they do not seem likely to be long term impacts to the price.  I had to purchase many sheets of plywood recently; the increase in plywood cost is astronomical.  I suspect plywood will drop 50% in the not too distant future.  OSB similar.  Other lumber has risen less significantly, but seems likely to drop in the near future. I expect building costs will come down as the cause of much of the increase is not something that should be on-going.

I agree that apartment living is currently as a significant low.  What I am less certain is if it will stay that way as the risks associated with COVID are reduced.  No way to know, but what I suspect is the lower costs associated with apartments will result in many migrating back to apartment living.  

In time we will know, but I will be surprised if supply costs do not come down.

Good luck

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  • Rental Property Investor · Santa Clara, CA · Member since 2019 · 160 posts · 156 votes
    4y
    Thank you! It's accessed from the backyard fence and has its own address and mailbox and delivery spot for packages.

    Originally posted by @Gabe T.:

    @Chen Zhou

    Wow that looks amazing Chen! That should rent nicely in the Bay Area.

    When it comes to ADUs I'm always interested to know how the unit is accessed and separated from the primary unit. I think that really impacts the appeal of the ADU. I can't really tell from the photos.

  • Member since 2022 · 1 post · 0 votes
    4y
    Quote from @Chen Zhou:

    Hi everyone,

    I've got tremendous help and support from this forum in the past 3 years. To give back to this community, I thought I'd share information on the second ADU project I'm working on in Santa Clara. I posted about my first ADU project in San Jose back in 2019 and shared 3D visual,

    pictures and numbers if you are interested: https://www.biggerpockets.com/...

    Building an ADU could be a daunting task and takes a lot of $$ and effort. So why is ADU a good idea? 

    The short answer: strong cash flow and immediate equity creation! It's been almost 2 years since my ADU project in San Jose was completed. I not only found (and kept) amazing tenants but also took out a home equity loan (through Figure.com) from the San Jose property at really good rates (whole process took 5 business days from application to money in my bank). Thanks to the red hot housing market, I was able to take out $250k, $50k more than the initial $200k that I invested into the San Jose ADU project. I'm planning on using the $250k home equity loan towards my second ADU project in Santa Clara.

    In fact, I realized that as long as I can create strong cash flow for each of my ADU projects, I can just rinse and repeat this process - invest the equity created from the last ADU project into building the next ADU. If done right, the rents from the last ADU would more than cover the home equity loan monthly payments + increased property tax.

    A little more about the Santa Clara ADU project I'm working on now:

    With the experience from the first project, this time around I'm more confident about who I should work with, budget, timeline, what kind of tenants and rents I'm able to get, and of course things to watch out for. In addition, California loosened the ADU regulations at the beginning of 2020. All bay area cities reduced fees, and made it easier for homeowners to build larger ADUs, which also made my decision easier.

    This time, I'm building a 2B1B 1200 sqft detached ADU in Santa Clara. The reason I designed a 2B1B instead of a 2B2B is that Santa Clara only allows 1 bathroom maximum at this time. However, I do expect the codes to relax overtime, so my architect designed a large walk in closet for one of the bedrooms that could be potentially convert into a bathroom in the event that Santa Clara allows a 2nd bathroom for ADUs in the future. Here's the floor plan if you are interested:

    I budgeted about $400k total for this project. Will see if I can pull this off.

    Other factors taken into account:

    1. Time horizon. I'm a buy-and-hold investor and I'm planning on holding on the property for decades, so instead of immediate resale value (which ADU doesn't compare very well with perhaps other rehab/flip projects), I care much more about long-term cash flow and long-term resale value. In the long-term, I think SFH with ADUs will sell very well because I do believe multi-generational living will be more and more common with 1) more immigrants moving to the bay area with their elderly parents and 2) baby boomers starting to take care of their elderly parents who need long-term care. Demographics are in favor of ADUs for sure. Also, who doesn't like additional rental income to help with the mortgage payments? But the ADU design needs to take these various scenarios into account and create enough separation/privacy between the 2 households living on the same lot.

    2. Rental market in the bay area. When the pandemic first hit in 2020, I wasn't very sure about building ADU since everyone started working from home and the bay area rental market was suffering as more people moved to cheaper places. However, since the vaccine rollout started, I saw more and more people moving back to the bay, and I'm confident most tech companies in the bay area are going to adopt a hybrid working model instead of a 100% remote model, which still requires people to live close to the offices/campuses.

    3. Cost of construction is going up every year (raw materials, labor, fees, etc.). So if you are contemplating on building an ADU, it doesn't hurt to start planning early. To me, the earlier I can start and finish the project, the lower the building cost will be and the earlier I can achieve better cash flow. Each day of delay is $$ lost.

    4. Effort and commitment. It IS hard work to build an ADU and it will take roughly a year from planning to finding tenants, but once it's done, you will benefit from the hard work for decades. So you want to make sure you are mentally prepared for the hard work going in and are committed to see it through. It will be a very gratifying process. Because of the large investment and high stakes, don't underestimate the importance of choosing the right designer & contractor to work with. You want experienced experts that can guide you through the process, not someone who adds additional stress to the whole process.


    Lastly, happy to answer any questions. Would love to connect with you if you are also building ADUs in the Bay Area.

    Cheers,

    Chen

    Thank you for sharing! I am new to ADU and don't know where to start. Do you mind sharing the contractor that you worked with?

  • Investor · San Jose · Member since 2022 · 3 posts · 1 vote
    4y

    @Chen Zhou, I am a newbie and inspired by your posts. Can you please share your Architect/Contractor information?

    I was quoted: $9500 for a design and $3000 for site survey because I am trying to decide between having an attached ADU vs a detached one.

    I have no idea what is a reasonable price for now. 

    Thank you!


  • Investor · Los Angeles · Member since 2021 · 16 posts · 10 votes
    4y
    Quote from @Chen Zhou:
    Originally posted by @David T.:

    @Chen Zhou Congrats! thanks for sharing! I see that you took out a home equity loan to finance this second ADU. Curious to hear why you didn't go with a cash out refinance route instead? Was the rate a lot lower with a home equity loan vs cash out refi?

    Actually cash out refi was my preference, but looks like very very few banks offer that during the pandemic, and even if they do offer, the total amount is typically capped at $1M, and the rates are not that good. My first mortgage's interest rate is very good:)

    Luckily I found Figure.com, who offers pretty good rates for a 30-year fixed home equity loan, which I thought is almost the equivalent of cash out refi, if not better. Plus the whole process was very hassle free and only took 5 business days. Didn't have to do appraisal (Figure does digital appraisal and gave me generous valuation) and didn't have to send them all the documents as I just needed to digitally link my bank accounts to their website for them to do cash flow analysis before they can approve the loan.

    Ultimately I thought in a few years when the property appreciates further, I will do cash out refi anyway to maintain my leverage, and at that time I can pay off both loans, so I didn't care too much about 1 loan vs. 2 loans at the moment.


    Hey Chen, I'm currently finishing a 1200 sq ft ADU in Los Angeles in 2 months, and will be using a HELOC to fund another ADU project when the plans get approved in the next 4 months on another home I already own. My question to you is how does Figure.com evaluate the ADU. Do you have to provide them with any information related to the newly build ADU, you said no appraisal no documents, but they still need to know some details about the size of the ADU weather or not the house and the ADU are rented, may be leases I imagine? if you could elaborate, it will be very helpful. Thank you for the great post btw

  • Rental Property Investor · Santa Clara, CA · Member since 2019 · 160 posts · 156 votes
    4y
    Quote from @Atanas Petrov:
    Quote from @Chen Zhou:
    Originally posted by @David T.:

    @Chen Zhou Congrats! thanks for sharing! I see that you took out a home equity loan to finance this second ADU. Curious to hear why you didn't go with a cash out refinance route instead? Was the rate a lot lower with a home equity loan vs cash out refi?

    Actually cash out refi was my preference, but looks like very very few banks offer that during the pandemic, and even if they do offer, the total amount is typically capped at $1M, and the rates are not that good. My first mortgage's interest rate is very good:)

    Luckily I found Figure.com, who offers pretty good rates for a 30-year fixed home equity loan, which I thought is almost the equivalent of cash out refi, if not better. Plus the whole process was very hassle free and only took 5 business days. Didn't have to do appraisal (Figure does digital appraisal and gave me generous valuation) and didn't have to send them all the documents as I just needed to digitally link my bank accounts to their website for them to do cash flow analysis before they can approve the loan.

    Ultimately I thought in a few years when the property appreciates further, I will do cash out refi anyway to maintain my leverage, and at that time I can pay off both loans, so I didn't care too much about 1 loan vs. 2 loans at the moment.


    Hey Chen, I'm currently finishing a 1200 sq ft ADU in Los Angeles in 2 months, and will be using a HELOC to fund another ADU project when the plans get approved in the next 4 months on another home I already own. My question to you is how does Figure.com evaluate the ADU. Do you have to provide them with any information related to the newly build ADU, you said no appraisal no documents, but they still need to know some details about the size of the ADU weather or not the house and the ADU are rented, may be leases I imagine? if you could elaborate, it will be very helpful. Thank you for the great post btw


    When Figure did the virtual appraisal for me (completely driven by publicly available data, no human involved), they simply just added the ADU sqft to the main house's and gave me a number within minutes of application. Hope it helps.

  • Investor · Los Angeles · Member since 2021 · 16 posts · 10 votes
    4y
    Quote from @Chen Zhou:
    Quote from @Atanas Petrov:
    Quote from @Chen Zhou:
    Originally posted by @David T.:

    @Chen Zhou Congrats! thanks for sharing! I see that you took out a home equity loan to finance this second ADU. Curious to hear why you didn't go with a cash out refinance route instead? Was the rate a lot lower with a home equity loan vs cash out refi?

    Actually cash out refi was my preference, but looks like very very few banks offer that during the pandemic, and even if they do offer, the total amount is typically capped at $1M, and the rates are not that good. My first mortgage's interest rate is very good:)

    Luckily I found Figure.com, who offers pretty good rates for a 30-year fixed home equity loan, which I thought is almost the equivalent of cash out refi, if not better. Plus the whole process was very hassle free and only took 5 business days. Didn't have to do appraisal (Figure does digital appraisal and gave me generous valuation) and didn't have to send them all the documents as I just needed to digitally link my bank accounts to their website for them to do cash flow analysis before they can approve the loan.

    Ultimately I thought in a few years when the property appreciates further, I will do cash out refi anyway to maintain my leverage, and at that time I can pay off both loans, so I didn't care too much about 1 loan vs. 2 loans at the moment.


    Hey Chen, I'm currently finishing a 1200 sq ft ADU in Los Angeles in 2 months, and will be using a HELOC to fund another ADU project when the plans get approved in the next 4 months on another home I already own. My question to you is how does Figure.com evaluate the ADU. Do you have to provide them with any information related to the newly build ADU, you said no appraisal no documents, but they still need to know some details about the size of the ADU weather or not the house and the ADU are rented, may be leases I imagine? if you could elaborate, it will be very helpful. Thank you for the great post btw


    When Figure did the virtual appraisal for me (completely driven by publicly available data, no human involved), they simply just added the ADU sqft to the main house's and gave me a number within minutes of application. Hope it helps.


     Great, that's amazing.  Thank you

  • Member since 2020 · 6 posts · 0 votes
    3y

    hi @Chen Zhou, thank you for your posts regarding both your ADUs and willingness to help others in the process. I really liked the way you shared the costs for your 1st ADU project. It would be great if you can share similar one for this ADU if you have it handy. I am also really interested in your thoughts on SB9 lot splits.

    I had been starting and stopping my plans for an ADU (as my property had some easement issues). I think I am finally ready to build. But now I am debating whether to build an ADU or do a lot split and built another smaller primary dwelling.

  • Rental Property Investor · Santa Clara, CA · Member since 2019 · 160 posts · 156 votes
    3y
    Quote from @Sara Pasha:

    hi @Chen Zhou, thank you for your posts regarding both your ADUs and willingness to help others in the process. I really liked the way you shared the costs for your 1st ADU project. It would be great if you can share similar one for this ADU if you have it handy. I am also really interested in your thoughts on SB9 lot splits.

    I had been starting and stopping my plans for an ADU (as my property had some easement issues). I think I am finally ready to build. But now I am debating whether to build an ADU or do a lot split and built another smaller primary dwelling.


     Hi Sara, the all-in cost for this one was $430k. Contractor $300k, finishing materials $60k, solar $10k, public work $10k, soft cost $20k, landscaping and other miscellaneous $30k.

    Whether to do SB9 or just ADU really depends on your lot (is it a corner lot? is it big/wide enough for you to divide into two or you have to do a flag lot?). You should also take into account that SB9 would be a lot more costly to do and takes longer. In addition, houses on smaller lot are not valued as much as same houses on a bigger lot, since most of the value of properties in California is in the land.

  • Member since 2020 · 6 posts · 0 votes
    3y

    Thanks for your thoughts. I dont have a very wide lot, but splitting my lot would give a slightly narrow ~4k sq ft lot. There are a ton of 4k lots in my city and they price well. Only concern is this will be narrow long lot. 

    I have to research more about the extra costs and time for SB9. The main reason for thinking about lot split is ADUs are not assessed very well yet. In a few years it might become a lot more common and might be assessed to the right value, but unfortunately, we are not there yet. 

    In your ADU, did you separate the utilities?

  • Rental Property Investor · Santa Clara, CA · Member since 2019 · 160 posts · 156 votes
    3y
    Quote from @Sara Pasha:

    Thanks for your thoughts. I dont have a very wide lot, but splitting my lot would give a slightly narrow ~4k sq ft lot. There are a ton of 4k lots in my city and they price well. Only concern is this will be narrow long lot. 

    I have to research more about the extra costs and time for SB9. The main reason for thinking about lot split is ADUs are not assessed very well yet. In a few years it might become a lot more common and might be assessed to the right value, but unfortunately, we are not there yet. 

    In your ADU, did you separate the utilities?

     Keep me posted on your effort and good luck! In my city (Santa Clara), the application cost of Sb9 is at least $50k+, not including all the additional cost of land survey, public work, adding separate water and gas meters, etc. I think it could be easily $100k-$150k more. And since the reduced lot also reduce the value of the main lot (by $200k-400k), I figured that it was not worth it for me. However, I think for bigger lots and in more expensive zipcodes, Sb9 would make a lot more sense.

    I have a separate electric meter (required by the city), but not separate gas/water meter.

  • Member since 2020 · 6 posts · 0 votes
    3y

    Thanks again for sharing info and will keep you posted. 

  • Member since 2026 · 1 post · 0 votes
    8mo

    Hi Chen, do you have your architect contact to share? Also wanted to know how you were underwriting your deals?

    would love to hear an update on how this project worked out for you.
    I am starting my journey in this avenue as of now and looking for some guidance

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