What’s the Cost of Converting a 330-350 Sq Ft Garage into an ADU/JADU?

[Jacky Peng]

Hi Bigger Pockets Community,

I recently decided to start a JADU project (330 sq ft) using my garage. The first quotation I received from my contractor is $90,000 ($273/sq ft), or $100,000 ($303/sq ft) if additional foundation work is required. The quote includes the HVAC machine and installation. I’d appreciate your thoughts on this quote, and any suggestions or advice would be welcome.

Thank you, 

Jacky

[Rene Hosman]

I am an investor in CO and we're doing a garage conversion including the room above the garage and that is looking like it's going to be 150k but that is for about 800 sq ft including some foundation work, adding a full bath, laundry hook up, and kitchentte. 

90-100 seems high for 330 ft to me but that may be CA prices! 

Have you had anyone else bid out the work? We got 4 quotes and went with the contractor whose quote came in the middle but we liked the most. 

I expect the project will be a bit cheaper than the quote because I've been sourcing materials myself which were included in the quote and was able to buy new hardwood flooring on fb marketplace as well as buying nice hardwood cabinets from Habitat Restore that will be refinished instead of buying new plus a few other fun thrifted finds to keep costs down!

[Jacky Peng]

Quote from @Rene Hosman:

I am an investor in CO and we're doing a garage conversion including the room above the garage and that is looking like it's going to be 150k but that is for about 800 sq ft including some foundation work, adding a full bath, laundry hook up, and kitchentte. 

90-100 seems high for 330 ft to me but that may be CA prices! 

Have you had anyone else bid out the work? We got 4 quotes and went with the contractor whose quote came in the middle but we liked the most. 

I expect the project will be a bit cheaper than the quote because I've been sourcing materials myself which were included in the quote and was able to buy new hardwood flooring on fb marketplace as well as buying nice hardwood cabinets from Habitat Restore that will be refinished instead of buying new plus a few other fun thrifted finds to keep costs down!

I appreciate you sharing this! I will be sure to get additional quotes in the near future. Since I am based in the Bay Area, the price per square foot is higher.

[Madri Koppe]

@Jacky Peng Definitely get multiple quotes and that will give you some basis for comparison. We’re in the same process and having seen several quotes the spectrum can vary greatly. 

[Rene Hosman]

@Jacky Peng I'm trying to convince my retired parents to do a garage ADU conversion out near SFO airport where they live so please keep us updated here on the forums, I look forward to hearing how this all goes for you and what other questions you have along the way!

[Jacky Peng]

Quote from @Madri Koppe:

@Jacky Peng Definitely get multiple quotes and that will give you some basis for comparison. We’re in the same process and having seen several quotes the spectrum can vary greatly. 

I will do that. I appreciate your response.

[Gi'angelo Bautista]

What else does the quote include or not include? The price seems reasonable thou if it includes everything. Definitely get a lot of quotes.

[Jacky Peng]

Quote from @Rene Hosman:

@Jacky Peng I'm trying to convince my retired parents to do a garage ADU conversion out near SFO airport where they live so please keep us updated here on the forums, I look forward to hearing how this all goes for you and what other questions you have along the way!

 Definitely!

[Jacky Peng]

Quote from @Gi'angelo Bautista:

What else does the quote include or not include? The price seems reasonable thou if it includes everything. Definitely get a lot of quotes.

Hi Gi'angelo,

According to my contractor, the quote includes materials that are not visible (such as lumber and cement), labor costs, and HVAC. I will need to pay out of pocket for visible items like paint, the shower, toilet, vanity, kitchen cabinets, wardrobe, and so on.

[Wilson Lau]

Hey @Jacky Peng. That's actually a very reasonable quote. It usually runs around $250-$300 for a garage conversion. 

[Dan H.]

I think your quote is low and it will end up costing more. How much ADU experience does your contractor have in your market? Is this to include everything? I expect ~$20k to $30k higher all in cost.

why are you choosing to do JADU vs ADU? JADU requires owner occupancy (ADU does not require owner occupied) and get even worst valuations than ADUs (which already get bad valuations in CA).
Make sure you do thorough underwriting.   In general ADUs in Sf zoned areas are a poor investment and JADUs are an even poorer investment.  in particular make sure you know the value that will be added by the ADU and that in your case both units may be rent controlled (no 15 year exemption in some jurisdictions for a garage conversion were garage is over 15 years old.  In most jurisdictions if house is over 15 years old it will be rent controlled once it is 2 units).  

good luck

[Jacky Peng]

Quote from @Wilson Lau:

Hey @Jacky Peng. That's actually a very reasonable quote. It usually runs around $250-$300 for a garage conversion. 

 Thank you for the feedback. 

[Jacky Peng]

Quote from @Dan H.:

I think your quote is low and it will end up costing more. How much ADU experience does your contractor have in your market? Is this to include everything? I expect ~$20k to $30k higher all in cost.

why are you choosing to do JADU vs ADU? JADU requires owner occupancy (ADU does not require owner occupied) and get even worst valuations than ADUs (which already get bad valuations in CA).
Make sure you do thorough underwriting.   In general ADUs in Sf zoned areas are a poor investment and JADUs are an even poorer investment.  in particular make sure you know the value that will be added by the ADU and that in your case both units may be rent controlled (no 15 year exemption in some jurisdictions for a garage conversion were garage is over 15 years old.  In most jurisdictions if house is over 15 years old it will be rent controlled once it is 2 units).  

good luck

It will end up costing more. According to my contractor, the quote includes materials that are not visible (such as lumber and cement), labor costs, and HVAC. I will need to pay out of pocket for visible items like paint, the shower, toilet, vanity, kitchen cabinets, wardrobe, and so on. So, your prediction that there would be at least $20k more if everything is included should be accurate.

The reason for choosing a JADU is that converting the garage into an ADU would require a separate laundry setup and an additional electrical panel in the main house, which would increase the renovation costs for the main house itself. By going with a JADU, I can share these items and keep costs down. I'm not sure if a JADU will affect the house's value, but since I just bought the house in May and plan to live in it for 10+ years, I'm happy as long as the garage can provide a steady cash flow to help offset my mortgage payments. I also have two other properties in the East Bay with much lower interest rates from the past three years.

Thank you for your input!

[Alecia Loveless]

@Jacky Peng I got a quote for about $110,000 for my garage space. It did involve having to put in 3 dormers. My space is maybe 400sq ft.

[Jacky Peng]

Quote from @Alecia Loveless:

@Jacky Peng I got a quote for about $110,000 for my garage space. It did involve having to put in 3 dormers. My space is maybe 400sq ft.

Hi Alecia, thank you for sharing this information.

[Neil Ginty]

Hi @Jacky Peng
$90-100 may well be doable. You should have $150k in mind though so you're prepared for worst case - and also to allow for soft costs (permit fees, etc.)
$75-90k is typical for a garage conversion ADU in Sacramento. Contractors I know say to expect $100-150k for Bay Area though

[Scott Scoville]

It depends on where you the property is located. I'm in Sacramento, and conversions for something like that can be done for under $100k. Bay are definitely over $100k. Get plenty of bids and vet your contractors. Referrals are the best.

[Rene Hosman]

@Jacky Peng Were you able to get more quotes for this? Have you decided if you think you'll move forward? Curious to hear if you have any progress or insights to share since the last few weeks!

[Jacky Peng]

Quote from @Neil Ginty:

Hi @Jacky Peng
$90-100 may well be doable. You should have $150k in mind though so you're prepared for worst case - and also to allow for soft costs (permit fees, etc.)
$75-90k is typical for a garage conversion ADU in Sacramento. Contractors I know say to expect $100-150k for Bay Area though

 Thanks for the input. 

[Jacky Peng]

Quote from @Scott Scoville:

It depends on where you the property is located. I'm in Sacramento, and conversions for something like that can be done for under $100k. Bay are definitely over $100k. Get plenty of bids and vet your contractors. Referrals are the best.

 Thanks for the note. 

[Jacky Peng]

Hi Rene,

I have received four quotes so far:

1. First Quote: $90,000 ($273/sq ft) or $100,000 ($303/sq ft) as mentioned in the initial posting.
2. Second Quote: $92,000
3. Third Quote: $158,290 (Including Interior Design)
4. Fourth Quote: $140,000 - $150,000

I plan to go with the first quote/contractor, as they've previously done renovations in the house, and I appreciate both their communication and work quality.

[Rene Hosman]

Quote from @Jacky Peng:

Hi Rene,

I have received four quotes so far:

1. First Quote: $90,000 ($273/sq ft) or $100,000 ($303/sq ft) as mentioned in the initial posting.
2. Second Quote: $92,000
3. Third Quote: $158,290 (Including Interior Design)
4. Fourth Quote: $140,000 - $150,000

I plan to go with the first quote/contractor, as they've previously done renovations in the house, and I appreciate both their communication and work quality.

 Great info to have and I'm glad you were able to validate that the first person was the right fit! Keep us updated on how the process goes, I'm looking forward to hearing - and maybe seeing - how it all turns out for you!!

[Lee Miller]

Perhaps it's irresponsible to suggest this, but you could potentially save money by being your own GC. It involves a lot of planning and people-managing, and knowing what going into building projects at least on a high level is key. So, you have to be kinda into learning that stuff, and having someone in the family or friend circle with some expertise is a big help. People say it can save around 30% on average, but of course you're internalizing some risk, too.