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A family firm, on your site through every phase.
Addition Building & Design is a design-build firm in Los Angeles, owned and run by the Ross family. Four to five projects a year, because that is how many the family can personally be present for.
Photograph · the team, studio session, 2025
The firm
Plan thoroughly. Tell the truth about cost and schedule. Build it right once.
Mike Ross founded Addition Building & Design on those three sentences, and they still decide how the company takes on work. Design and construction sit under one contract, so the drawings, the engineering, the permit and the build are settled by the same people. Nothing is lost between an architect's office and a contractor's yard.
The firm stays small on purpose. A handful of significant projects a year means the people whose name is on the company are the people walking your site, reading your drawings and signing your contract. Christine Ross, Mike's daughter, is usually the first voice you hear and the one carrying the firm forward.
The people
Two principals, one small team, no rotation of project managers.
Mike Ross
Founder & CEO · BuilderMike holds the license, signs the contract and walks the site. Over four decades as a builder in Los Angeles he has settled designs with his architects and designers, had them engineered by his structural engineers, pulled the permits and hired the trades for custom homes, hillside residences and, since 2025, the rebuilds. He is interested in new building technology and has a long record of design-led companies that perform.
The firm has been nominated for Houzz national awards and named to Qualified Remodeler's Top 500 eight times. Away from the site he serves on university and civic boards, speaks on leadership, and has written three books.
Christine Ross
Managing PartnerChristine leads business development for the firm and is usually the first person a new client talks to. She walks homeowners through what a project will involve, keeps every question answered in plain language, and stays in the conversation from the first call to the finished house. She is the second generation of the family in the business and the one carrying it forward.
Professional Builder magazine nominated her for its Top 40 Under 40 in 2023, and she has appeared on Bravo's Million Dollar Listing.
Keith Marlow
Scheduler & Job Cost SpecialistMore than a decade in construction on both sides of the desk, in the field and in procurement and production. Keith builds the schedules clients can rely on, tracks every dollar against the budget, and keeps the vendor relationships that get materials to site on the day the schedule says.
Juan Frias
SuperintendentThe daily presence on our job sites. Juan is the firm's eyes and ears in the field, keeping each project safe and moving. Clients learn quickly that there is no need to email him: he is on site and glad to talk it through in person.
Michael Guarino
Finish & Punch List LeadThe last set of hands on every project. Michael completes the final punch list with skills across the trades and an eye for the detail others miss. It is exacting work, and it is why our homes are handed over finished.
Lola Paja
Executive AssistantLola keeps the executive team organized and the details moving. Her background spans executive support, operations and project coordination, with hands-on time in the trades as a flooring apprentice and on commercial sets.
Alyssa Riha
Administrative AssistantAlyssa keeps the office running. With a background in executive assistance and customer service, she sets the standards the office works to and makes sure everyone, clients included, feels looked after.
Father and daughter
You work with the family that owns the company.
Four to five projects a year is the only way a family can stay personally involved in every build and hold to the budget it quoted. Mike is the contractor of record on every home. Christine is the person who calls you back. Between them is one phone number: 310.617.2722.
In a client's words
I had an amazing experience with Addition Building & Design. From start to finish, they were a company I could trust, providing high-quality work that was consistently on time and within budget.Rich and Dwight · clients
More clients, in their own words
On time, in budget, and the house they wanted.
B Rogers
"Mike ran the project like a 100-seat symphony and orchestrated all the trades in perfect harmony. My job was completed on time, on budget, and my family was completely in love with our new home."
Renee and Jack Goldin
"He put together a contract which was comprehensive and subject to many revisions before meeting our approval. He has lived by every word of that contract."
Marilyn S
"I was under a time restraint to move in and he completed the renovation in 5 weeks! I was able to move in and have Thanksgiving in my new home. He was fair and much more important, he was honest."
In print
Better Homes and Gardens, January 2019.
A home by the firm on the cover and across five spreads inside. The kind of recognition that follows quiet work rather than announces it.
- Better Homes and GardensCover, January 2019
- Qualified Remodeler Top 500Eight times
- Houzz4.9 rating, national award nominations
- Best of Houzz 2024Service and design
- Houzz TVA surprise remodel for Mila Kunis’s parents
- Voyage LAAn interview with Christine Ross
Where to find us
Two offices, one licence, one phone number.
The city office
4335 Van Nuys Blvd, Suite 354
Sherman Oaks, CA 91403
The Conejo office
5776 Lindero Canyon Rd, Suite D446
Westlake Village, CA 91362
310.617.2722
Licensed California general contractor, CSLB #925471. Contact page, or write to Christine@abdbuild.com.
Private Consultation
Begin with a conversation.
We take on a select number of significant projects each year. If you are considering a custom estate, a hillside build, or a full transformation, we would be glad to walk the property with you.