Architect

Buff and Hensman

Born 1948

Profile

About Buff and Hensman.

Buff and Hensman was a Pasadena-based architectural firm founded in 1948 by Conrad Buff III and Donald Hensman, both then-undergraduates at the USC School of Architecture. The firm designed roughly 200 residences across Southern California from the 1950s through the late 1990s, with the heaviest SGV concentration in Pasadena, Altadena, and San Marino. SGV anchors include Case Study House 20 (the Saul Bass House) in Altadena (1958), the Frank House in Pasadena (1957), and the Thompson Moseley House in San Marino (1959). Pasadena's Poppy Peak Historic District (NRHP 09000182, listed 2009) contains a significant cluster of firm work. The firm operated under four names across its history: Buff and Hensman (1948 to 1957), Buff, Straub and Hensman (1957 to 1961), Buff, Hensman and Associates (1962 to 1989), and Buff, Smith and Hensman (1989 to present).

Buff and Hensman (Wikidata Q4985591) was a Pasadena architectural firm founded in 1948 by Conrad Buff III and Donald Hensman, both then-undergraduates at the USC School of Architecture. From the 1950s through the late 1990s the firm designed roughly 200 residences across Southern California, with the heaviest concentration in Pasadena, Altadena, and San Marino. The signature is the wood post-and-beam house: exposed Douglas fir structure, floor-to-ceiling glass, low or flat roofs with deep overhangs, and indoor-outdoor living organized around courts and view axes. The firm won more than 30 American Institute of Architects awards for residential design, and both founding partners were elevated to Fellow of the AIA (Conrad Buff III FAIA 1980; Donald Hensman FAIA). Its highest-profile project is Case Study House #20, the Saul Bass House, built in Altadena in 1958.

The firm operated under four names across its history. Buff and Hensman (1948 to 1957). Buff, Straub and Hensman (1957 to 1961, with USC professor Calvin C. Straub). Buff, Hensman and Associates (1962 to 1989), after Straub left to teach at Arizona State. Buff, Smith and Hensman (1989 to present), after Conrad Buff III died and Dennis Smith joined the practice. Don Hensman remained active in Pasadena until his death in 2002. The firm continues today in Pasadena under the Buff, Smith and Hensman name.

For a buyer evaluating an SGV property attributed to Buff and Hensman, three things determine whether the house is intact or compromised. The structural system. These are wood post-and-beam houses, not stick-framed houses with decorative beam treatments. The exposed posts are typically 4-by-6 or 6-by-6 Douglas fir, doing real load work on a regular grid. Boxing them, removing them, or replacing them with steel changes how the house reads and how it works. The glazing. Originals use floor-to-ceiling single-pane fixed glass in slim wood frames. Replacements with aluminum sliders, vinyl frames, or heavy divided lights break the architectural reading even when they improve energy performance. The site. These houses were sited specifically against trees, slopes, and view corridors. Cleared landscapes, filled hardscape, and added perimeter walls disrupt what the original design was solving for.

The SGV catalog runs through Pasadena, Altadena, and San Marino. Pasadena holds the largest concentration. The John Norton House in Southwest Pasadena, 1954. The Wirick House, late 1950s. The Frank House at 919 La Loma Road (NRHP 09000175), 1957, built for the Frank family of Lawry’s Foods. The Conrad and Libby Buff Residence at 480 Glen Holly Drive, the senior partner’s personal home. The Ajioka House, 1960. The Holland-Goudzwaard Residence, 1958. Altadena’s anchor is Case Study House #20, the Bass House, designed for graphic designer Saul Bass and his wife Ruth in 1958. San Marino holds the Thompson Moseley House, 1959. Pasadena’s Poppy Peak Historic District (NRHP 09000182, listed December 23, 2009) contains a significant cluster of firm work and is the densest place in the SGV to see Buff and Hensman houses next to each other.

How to identify a Buff and Hensman house in the San Gabriel Valley

Look for exposed wood post-and-beam structure that runs from interior to exterior. Walls of fixed single-pane glass in slim wood frames. A low or flat roof with deep cantilevered overhangs. An entry that is set back and screened behind a planted court rather than oriented to the street. The firm built in concentrations in Pasadena, Altadena, and San Marino, often on hillside lots that allowed the house to step with the grade.

The exposed structure is the diagnostic. Stick-framed mid-century houses sometimes carry decorative beam treatments that mimic post-and-beam without real structural members. Buff and Hensman did not do this. The posts carry the load. Beams sit on top of the posts and extend through the wall plane to support roof overhangs that can run four to eight feet deep. Glass infills the bays between posts. Solid walls occur only where privacy or service required them: the kitchen back wall, bathrooms, and bedroom closets.

Roof profiles are almost always flat or low-pitched with a single direction of slope. Tar-and-gravel was the original specification on most flat roofs. Newer single-ply membrane or torch-down roofs are acceptable replacements. What matters more is whether the original profile and overhangs survived. Some owners added pitched roofs over portions of the house to address chronic leaks, and those additions change the silhouette, the eave detail, and the structural reading. They tell you the house has been compromised.

Entries are rarely oriented to the street. The front facade typically reads as a wood-and-glass screen with a planted court between the street and the door. The entry sequence walks the visitor along the structure rather than at it.

The partnership and the firm’s history

The partnership began in 1948 when Conrad Buff III and Donald Hensman were USC architecture undergraduates designing tract and model homes for a regional developer. While still students, both were invited by the Dean of the School of Architecture to take over the teaching duties of a senior professor who had died. They were working professionals, students, and teachers at the same time, and both went on to long teaching careers at USC.

In 1957 the partnership merged with Calvin C. Straub, an established USC professor and a senior figure in California post-and-beam residential design. The merged firm, Buff, Straub and Hensman, lasted from 1957 to 1961 and produced roughly 30 projects, several of which became the firm’s most-published work. Straub left in 1961 to teach architecture at Arizona State University, and the firm continued as Buff, Hensman and Associates through 1989.

Conrad Buff III died in 1988 (Wikipedia gives October 10). Dennis Smith joined the practice the following year, and the firm became Buff, Smith and Hensman. Don Hensman retired in 1998 and died in 2002. The firm continues to practice under the Buff, Smith and Hensman name in Pasadena. Across all four name configurations the office won more than 30 American Institute of Architects awards for residential design.

The SGV catalog: Pasadena, Altadena, and San Marino

The firm’s SGV work clusters in three cities. Pasadena holds the largest share, Altadena holds the most-published single project, and San Marino holds a smaller but documented presence.

In Pasadena, the John Norton House in Southwest Pasadena, 1954, is one of the earliest published firm projects. The Frank House at 919 La Loma Road, 1957, was built for the Frank family of Lawry’s Foods. The Conrad and Libby Buff Residence at 480 Glen Holly Drive served as the senior partner’s own home and demonstrates the firm’s working vocabulary on a personal site. The Wirick House, the Ajioka House (1960), and the Holland-Goudzwaard Residence (1958) all sit in the Pasadena area. The Poppy Peak neighborhood, listed on the National Register of Historic Places in 2009, contains a notable concentration of firm work.

In Altadena, Case Study House #20, the Saul Bass House, 1958, is the firm’s most-published single project. It was one of the wood post-and-beam entries in the Case Study House Program and was built of factory-produced stressed-skin panels and plywood vaults. The plywood vault system was novel enough that Altadena building officials refused a permit until the architects erected a sample vault on site and loaded it with weights to demonstrate the engineering. The house is in private ownership and is recognized as a significant work of California mid-century modernism.

In San Marino, the Thompson Moseley House, 1959, demonstrates the firm’s vocabulary applied to a flatter lot with mature site planting, with classic post-and-beam structure, clerestory glazing, and walls of glass framing the deep lot.

The firm’s design vocabulary

The firm’s design language is consistent enough across its 50-year run that a trained eye can identify a Buff and Hensman house from the street. Five elements recur.

Wood post-and-beam structure on a regular grid, with Douglas fir posts spaced to organize the plan. Beams that pass over the posts and extend through the wall plane to support deep eave overhangs. Floor-to-ceiling single-pane fixed glass in slim wood frames, with the glass meeting the corner without a structural post where the plan allowed. Low or flat roofs, almost always with a single direction of slope, and overhangs that can run four to eight feet from the wall plane. Site-driven entries hidden behind planted courts rather than oriented to the street.

The firm’s published work was photographed extensively by Julius Shulman, whose images set the visual record for what these houses looked like at completion. The Shulman record is useful for authenticity assessment because it shows the original glazing patterns, original site planting, and original roof and overhang profiles before later modifications.

Authenticity assessment from a builder’s perspective

I worked as a finish carpenter on post-and-beam houses in Colorado before reactivating my real estate license in 2024. Post-and-beam construction follows the same basic structural principles whether it’s a mountain custom home or a 1950s Southern California modernist house: exposed posts carrying real load, beams passing over them, glass infill between. From that vantage, the three most diagnostic checks on an SGV Buff and Hensman house are the structural posts, the eave detail, and the glazing.

The posts should be exposed, continuous from floor or slab to roof structure, and visibly carrying load. If a post has been boxed in drywall, the house has lost its primary architectural reading. If posts have been removed and headers added, the structural load path has been re-routed, and depending on engineering quality the house may have settlement issues at the modified bays.

The eave detail is the second check. Original beams extend through the wall plane to support the roof overhang. The beam tail should be visible and finished. If the eave has been wrapped in fascia board to enclose the beam tails, the original detail is hidden and possibly damaged. Rot at the beam tail is the most common structural issue on these houses because the original detail exposes end-grain wood to weather; repairs done correctly preserve the visible beam tail with replacement wood and proper flashing, while repairs done incorrectly wrap the whole eave in trim.

The glazing is the third check. Originals are single-pane fixed glass in slim wood frames. Replacements with vinyl, aluminum, or thick divided lights change the proportion of the window opening to the structural bay. Energy upgrades to dual-pane glass can be done sympathetically with custom wood frames matching the original profile, but most replacements are off-the-shelf product that breaks the architectural reading.

Beyond those three, look at the floors, the kitchen back wall, and the entry court. Original floors were typically concrete slab or wood plank over slab. Original kitchen back walls were the solid wall against which the post-and-beam structure terminated. Original entry courts were planted and screened. Modifications that fill the entry court with hardscape, that tile or carpet a slab floor, or that open the kitchen back wall to create a great-room change the way the house performs.

Today: preservation status and SGV market presence

Buff and Hensman houses in the SGV trade in the architecturally significant tier of the regional market. Listings typically cite the architect attribution as a primary selling point and command a premium over comparable square footage in similar locations. The Pasadena Poppy Peak Historic District and the broader Altadena mid-century inventory contain the densest concentration of firm work, and the Eaton Fire of January 2025 affected portions of Altadena. Buyer due diligence on any Altadena attribution from this period should include a verification of which specific properties remained intact, as the fire footprint touched some areas of mid-century inventory and left others untouched.

Preservation status varies by jurisdiction. Poppy Peak is a National Register Historic District. Individual properties may carry Mills Act contracts, which provide a property tax reduction in exchange for a documented maintenance plan and approval gates on exterior alterations. A Mills Act contract on a Buff and Hensman house is a strong sign of an owner committed to preservation, and the contract itself transfers with the property at sale.

For a buyer evaluating a Buff and Hensman attribution, the verification path is straightforward. Check the building permit record at the city or county building department for the original architect. Cross-reference the Pacific Coast Architecture Database firm record. Check the Julius Shulman photographic archive at the Getty Research Institute for original photography of the house. An attribution that survives all three checks is solid. An attribution based only on listing copy or anecdote should be verified before a buyer pays the architect premium.

Styles

Associated Styles.

Works

Notable Works in the SGV.

Sources

Sources and references.

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This guide is informational and is not legal, tax, or financial advice. Mills Act eligibility, ADU permitting, and property tax implications vary by property and by year. Consult the relevant city, the Los Angeles County Assessor, and a licensed tax professional for guidance specific to your situation.