---
title: "Castor Architecture — Architects & Building Designers | Houzz"
canonical_html_url: https://www.houzz.com/professionals/architects-and-building-designers/castor-architecture-pfvwus-pf~1099358795
markdown_url: https://www.houzz.com/md/professionals/pf~1099358795.md
entity_type: LocalBusiness
business_name: "Castor Architecture"
category: ["Architects"]
image: https://st.hzcdn.com/fimgs/ef93a432061d2ddf_5049-w400-h400-b0-p0--.jpg
address: "Contact for Appointment, Mill Valley, California 94941, United States"
latitude: 37.8958
longitude: -122.5339
phone: "(415) 383-9400"
website: http://castorarchitecture.com/
rating: 5
review_count: 2
followers: 44
last_updated: 2026-08-21
---

# Castor Architecture

Original Houzz profile: [Castor Architecture](https://www.houzz.com/professionals/architects-and-building-designers/castor-architecture-pfvwus-pf~1099358795)

## Professional summary

- **Primary category:** Architects
- **Location:** Mill Valley, CA
- **Serves:** San Francisco, Richmond, San Rafael, Mill Valley, Larkspur, San Anselmo, Tamalpais-Homestead Valley, Corte Madera, Tiburon, Sausalito, Lucas Valley-Marinwood, North Richmond, Santa Venetia, Marin City, Sleepy Hollow, Ross, Belvedere, Fairfax, Lagunitas-Forest Knolls, Woodacre, Bolinas, Alto, Stinson Beach, Muir Beach, San Geronimo, Belvedere Tiburon, Forest Knolls, Greenbrae, Lagunitas, San Quentin
- **Houzz rating:** 5.0 out of 5 (2 reviews)

## About

### Houzz Badges

- Star Houzzer
- 1,000 Ideabook Saves

Castor Architecture is based in Mill Valley, CA with projects from Marin County to the Wine Country, San Francisco and the Peninsula.  

We choose to maintain a small team so that we can focus on doing a few things at a time, and doing them well.  We specialize in single family residences, from estates and new construction to additions and renovations.  Because the home exemplifies what called us to architecture in the first place – not only that we can achieve beauty, but that we can also make room for living.

### Services Provided

- Architectural Design
- Building Design
- Home Remodeling
- Custom Homes
- Home Additions
- Kitchen Design
- Bathroom Design

### Areas Served

- San Francisco
- Richmond
- San Rafael
- Mill Valley
- Larkspur
- San Anselmo
- Tamalpais-Homestead Valley
- Corte Madera
- Tiburon
- Sausalito
- Lucas Valley-Marinwood
- North Richmond
- Santa Venetia
- Marin City
- Sleepy Hollow
- Ross
- Belvedere
- Fairfax
- Lagunitas-Forest Knolls
- Woodacre
- Bolinas
- Alto
- Stinson Beach
- Muir Beach
- San Geronimo
- Belvedere Tiburon
- Forest Knolls
- Greenbrae
- Lagunitas
- San Quentin

### Typical Job Cost

$250,000 - 10 million

## Business Details

| Field | Value |
| --- | --- |
| Business Name | Castor Architecture |
| Address | Contact for Appointment, Mill Valley, California 94941, United States |
| Phone | (415) 383-9400 |
| Website | http://castorarchitecture.com/ |
| License Number | C-31089 |
| Followers on Houzz | 44 |

## Contact

- **Houzz profile:** [Castor Architecture](https://www.houzz.com/professionals/architects-and-building-designers/castor-architecture-pfvwus-pf~1099358795)
- **Website:** http://castorarchitecture.com/
- **Phone:** (415) 383-9400

## Reviews

**Overall rating: 5.0 out of 5 — 2 reviews**

### All 2 reviews

**★★★★★ — Robert Hawk, June 2017**

> Daniel was the architect for my house in Palo Alto, finished in 2009.  He did an absolutely great job in every respect.  In terms of the finished product, the design reflects both my own preferences and tastes, communicated during the design phase, and Daniel's own vision and style.  Although the house fits with the neighborhood (developed in the 1940's and 50's), the design is distinctive and accomplishes what I wanted.  Daniel was particularly adept at dealing with a very arduous planning process, complicated by constant complaints and challenges from an unreasonable neighbor.  Although the design is bold in some respects (which involved  building a second story where only a single level house had been before), Daniel was a forceful advocate before the Palo Alto Planning Department, ultimately getting the plans approved with quite positive comments from the City.
>
> Daniel was also quite competitive with respect to fees.  I love the house in large part because of its design, and I continue to receive frequent complements on it.  Now, in 2017, because of the fine job that Daniel did on my Palo Alto house, I have again engaged Daniel to design and prepare the plans for a major remodel of a house in Palm Springs.  I recommend Daniel without reservation.

**★★★★★ — Lynn Hering, June 2017**

> We hired Daniel Castor to renovate our 1930-era house, originally a cabin, which had been added on to and changed over the years to ill-effect.  The existing floor-plan was dysfunctional, with poor flow and a too-small kitchen and no dining room.  Daniel worked within the limitations imposed by our desire to work within the existing setbacks; that is, we did not want to have a lengthy process involving design-review hearings.  He managed to come up with a brilliant addition which gave us a fabulous large kitchen and an added dining room, all within the existing setbacks.  The room flow problem was solved by a radical, but necessary, moving of the staircase.  We are thrilled with the result and recommend Daniel unreservedly.  He was very easy to work with, had great ideas, and was an excellent problem solver.  He shows great attention to detail and is very sensitive to traffic flow / practical usage, as well as being very conscious of the mathematical proportions of a room / living space.  Oh, by the way, he designed a stunning wooden-truss canopy over our outside entryway.

## Selected projects

- [Vineyard Residence \| St. Helena, CA](https://www.houzz.com/hznb/projects/vineyard-residence-st-helena-ca-pj-vj~2726078)
  - Location: Saint Helena, CA
  - Photos: 7
- [Cottage Industrial \| Mill Valley, CA](https://www.houzz.com/hznb/projects/cottage-industrial-mill-valley-ca-pj-vj~2726087)
  - Location: Mill Valley, CA
  - Photos: 8
- [Parish Revival \| Mill Valley, CA](https://www.houzz.com/hznb/projects/parish-revival-mill-valley-ca-pj-vj~1873671)
  - Location: Mill Valley, CA
  - Photos: 10
- [Stone Hill Retreat \| Sonoma, CA](https://www.houzz.com/hznb/projects/stone-hill-retreat-sonoma-ca-pj-vj~1873668)
  - Location: Sonoma, CA
  - Photos: 5
- [Portal & Courtyard \| Palo Alto, CA](https://www.houzz.com/hznb/projects/portal-and-courtyard-palo-alto-ca-pj-vj~1873679)
  - Location: Palo Alto, CA
  - Photos: 4
- [Formal Farmhouse \| Sonoma, CA](https://www.houzz.com/hznb/projects/formal-farmhouse-sonoma-ca-pj-vj~1873665)
  - Location: Sonoma, CA
  - Photos: 8
- [California Classic \| Brentwood Park, CA](https://www.houzz.com/hznb/projects/california-classic-brentwood-park-ca-pj-vj~1873660)
  - Location: Brentwood, CA
  - Photos: 7
- [Board, Batten, & Barn \| Sonoma, CA](https://www.houzz.com/hznb/projects/board-batten-and-barn-sonoma-ca-pj-vj~1873656)
  - Location: Sonoma, CA
  - Photos: 7
- [Artsy Craftsman \| Mill Valley, CA](https://www.houzz.com/hznb/projects/artsy-craftsman-mill-valley-ca-pj-vj~1873652)
  - Location: Mill Valley, CA
  - Photos: 5
- [An Acre of Sun \| Los Altos Hills, CA](https://www.houzz.com/hznb/projects/an-acre-of-sun-los-altos-hills-ca-pj-vj~1873650)
  - Location: Los Altos Hills, CA
  - Photos: 7

[See all 10 projects](https://www.houzz.com/professionals/architects-and-building-designers/castor-architecture-pfvwus-pf~1099358795)

## Ideabooks

- [195 Ethel Ave.](https://www.houzz.com/ideabooks/72165758/list/195-ethel-ave) — 2 ideas

[See all 1 ideabook](https://www.houzz.com/ideabooks/users/castorarchitecture1)

## Community Q&A

**Q: what is the color of the window trim? love it!** *(in Photo Questions)*

A: Those are Kolbe windows with one of their standard factory colors, I forget the name.

**Q: Board and batten** *(in Photo Questions)*

Was pine used? Was it stained or left natural?

A: It is Redwood, which will eventually fade to gray unless you stain it.

**Q: How long is this table** *(in Photo Questions)*

A: It was a long table - I am guessing 8'-0".

**Q: Parish revival** *(in Photo Questions)*

Would you be able to share the manufacturer of the dining room chairs?

A: I'm afraid I don't know where the owners found the chairs.  I doubt they are still in production.

**Q: Tell me about the backsplash, cabinets and floor. Where can I find the** *(in Photo Questions)*

Dominique, North Andover, MA

A: Hi there.  The cabinets are covered with a Black Walnut veneer.  The back splash ceramic tiles are from Import Tile in Berkeley.  The floor tiles are a kind of limestone, from Integrated Solutions in South San Francisco.  You can't see them in the photo, but they have little critters in them, from an ancient sea bed.

---

*Source: Houzz professional profile. Reflects the profile as of 2026-08-21.*