ADU Collective specializes in urban infill through the design of Accessory Dwelling Units.  Our goal is to streamline the process while considering the unique needs of each project. We have extensive experience with conversions, additions and new construction. Get in touch to determine if an Accessory Dwelling Unit is the right solution for you.



What is an ADU?

An accessory dwelling unit or "ADU" is space on your property that is suitable for occupancy separate from the main dwelling. This means that it will have facilities that include a kitchen, bathroom, and sleeping area. Additional information about ADUs can be found at this California State Website.

How much does it cost to build an ADU?

Depending on your specific needs, and whether your ADU will include a garage conversion, addition, or new construction, cost will of course vary. We find that most ADUs will fall somewhere in the range of $170,000 to $300,000. You can see a breakdown of example project costs in this presentation or visit this website created by San Mateo County that is an easy to use ADU calculator​.

How long will it take?

Once design is complete and permits approved, construction moves quite quickly. We find that most projects can be completed within 12 months. The design portion can vary depending on client needs. A simple conversion can take just a few meetings to develop a plan that works for a client, but we find most project have custom considerations that take a little longer to work out together. A good estimate is to allow about twelve weeks for design and submittal to the building department.


What are the new State Laws?

The State of California has passed laws effective 1/1/2020

  • AB 670 (Friedman): Signed by Governor. Homeowners associations must allow ADUs and JADUs as of 1/1/20.

  • AB 671 (Friedman): Signed by Governor. Housing Elements will need to incentivize and promote the creation of ADUs at all income levels. HCD will develop, and post, a list of existing state grants and financial incentives for ADUs.

  • AB 587 (Friedman): Signed by Governor. Will allow a non-profit to separately convey title to ADUs.

  • AB 68 (Ting) / AB 881 (Bloom) / SB 13 (Wieckowski): Signed by Governor. Together these three bills will amend existing ADU law as follows:

How do they affect ADUs?

  • Zero setback if conversion of an existing structure at property line.

  • Maximum 4’ side and rear setbacks for newly constructed ADUs.

  • Must allow a minimum of an 800 sf efficiency or 1 bedroom ADU, or a minimum of 1,000 sf for 2+ bedrooms (no lot coverage, floor ratios or open space requirements can reduce this minimum)

  • Minimum 16 ft. height allowed.

  • One ADU and one JADU by right on a single-family lot.

  • One JADU by right with a full kitchen.

  • ADUs allowed in multi-family and mixed-use zones. Up to 2 detached ADUs, plus conversion of uninhabited spaces for multiple ADUs (up to 25% of units in multifamily buildings).

  • No minimum lot size for ADUs.

  • 60-day permit processing, or deemed approved.

  • No replacement parking for garage conversions.

  • Proximity to transit must be “walkable” to qualify for parking waiver.

  • No impact fees on ADUs less than 750 sf, if larger, impact fees to be proportional to main house.

  • 5-year moratorium on local owner-occupancy restrictions until 1/1/25.

  • Mandatory 5-year stay of enforcement on unpermitted ADUs if they meet health and safety standards.

  • No short-term rentals of ADUs or JADUs.











Jessica Resmini


JaWen Hernandez



Keleigh Grimm

Project Manager

John Kelley



Jaime Resmini

Design & Marketing

Kari Kirkpatrick




Possibly the best superpower of all is the ability to unexpectedly communicate in another language, revealing a razor sharp competency beneath an unassuming exterior. 

When we first met our architect Jessica, finding a superhero was not foremost on our minds.

Mainly we were looking for creativity and functionality, someone who could help us translate our needs and ideas into feasible plans. In fact, one of the selling points she gave when we initially interviewed her was her ability to listen. She did listen, and ultimately delivered a design that we love, despite the limitations of square footage and physics. It was a fun process, and we looked forward to our meetings with Jess as the plans and ideas evolved. I learned new terms such as soffit and fascia, and even picked up a few skills. Who knew that all you need to draw a toilet is a rectangle and a circle? Amazing. The best thing was that she seemed so normal, a mom with two young boys, fun to chat with, and genuinely nice.

Her superpowers, however, were not immediately apparent, until we sat together in a city planning meeting discussing roof lines and aesthetics; without warning she suddenly code-switched and spoke with the planners like an expert. The review board pretended to be friendly, but then lunged like cobras: "The PROBLEM with the gidniff is that it's too snorky. It needs to be more mostrilesque." She countered coolly, "these gidniffs are burukated in such a way that the oopside bunderhosts geminally." Ahhh. said the planners. "good point." Booyah. David and I glanced at each other in bewilderment and relief. She can talk the talk! The same thing followed in exchanges with structural engineers, contractors, city workers and green consultants. She knew what they were talking about, too!

Like any self-respecting superhero, Jessica could also walk the walk, as it turned out. She's crawled into our crawl space to measure the spacing of the supports, and scaled our roof in a single bound, to determine the best views for our second story windows . Our experienced contractor has remarked more than once that Jess' plans are the most detailed he's ever seen. So here's to you, Jessica. Our gidniffs will forever be burukated, and we thank you.

Evi Klein

 Jessica arrived at our original project at a critical and chaotic time and was able to professionally and efficiently pull together a very successful solution in spite  of the challenges.  

    We have since engaged her to design a much larger and more complex project. We are not only delighted with her fantastic architectural style, but as importantly her ability to incorporate maximum efficiency.  

    We don’t know what to rate as her greatest asset;  her professionalism, her style of communication and collaboration; the personal care and concern she demonstrates throughout the project and of course, her unique gift in design.   In addition, she has been a spot on resource beyond her scope of work by volunteering recommendations for project management, great people, products and price.  

    She is that bright light we all hope to find as we fumble our way down the dark tunnel of construction.

Patricia Giffin

I engaged Jessica to design a new accessory guest house and worked with her extensively during the design process. She was great about taking my general (and often vague) ideas and converting them into a fantastic design. She really did a wonderful job of making sure that the new house fit with the look, aesthetics, and general feel of my main house and the backyard in general. Jessica was also able to navigate the complicated and sometimes contradictory requirements of the Palo Alto building department and took care of all the permitting for the project. One really great thing about Jessica is she didn't just hand the builder a set of plans and walk away. Instead she was really involved during the construction phase and was often on site making sure everything went according to plan. She had a great interaction with the contractor which really helped to make sure everyone had the same vision. I've had many people comment on how great the new guest house is and that it fits in so well that it looks like it was always there. I use it every day as my office when guests aren't over and I absolutely love it. In fact, I was so happy with her work that I hired her for some remodels on my main house and they came out fantastic. I can absolutely recommend Jess - she is great! In fact, both my sisters have hired her and my parents will probably do the same. None of them knew they wanted to do work but my project really inspired them.

Robert Klein

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