SF Assessor records date 313 Hearst Avenue to 1900 and 2 Foerster Street to 1925. Both addresses sit south of Monterey Boulevard, comparable distance from the old streetcar corridor, comparable elevation, same subdivision platted the same year. The obvious explanation for the twenty-five-year gap is grade: Foerster climbs steeper terrain, so builders got there later. But the low-numbered Foerster houses occupy lots no higher than their Hearst counterparts. The gap is not vertical. Walk the residential cross streets between Hearst and Foerster, and the facades sort themselves into decades — siding materials, window proportions, the appearance of garages — recording a fill that moved not uphill but westward, one street at a time.
The development frame is well documented. The Sunnyside Land Company subdivided the southern 200 acres of the old Rancho San Miguel in 1891, platting 48 blocks across terrain that ranged from the gentle grade along Monterey Boulevard to slopes steep enough to become staircases a century later. Behrend Joost, who founded the company, launched San Francisco's first electric streetcar through the new subdivision in April 1892. The streetcar was supposed to sell the lots. The grid gave the lots their shape. The 2,250 parcels were the wager. As the SNA notes, Sunnyside remained sparsely populated for years after the subdivision. Development picked up after the 1906 earthquake sent displaced families south, accelerated through the 1920s, and continued filling hillier streets into the 1950s. The Library of Congress holds Sanborn fire insurance maps from 1900 and 1914 that cover San Francisco at the parcel level, recording which lots held structures and which sat empty. The 1900 edition, drawn nine years after the Land Company's subdivision, would show how few of those 2,250 lots had found builders. The 1914 edition would show the post-earthquake wave arriving. Together they map the same lateral fill that the Assessor dates compress into numbers.
That four-decade sequence is the macro story. The walk tests it at the scale of individual block faces, where the Assessor dates become legible in wood grain and stucco, in the presence or absence of a garage door.
Hearst Avenue, 310s–370s
Start on Hearst south of Monterey, where the 300-numbered houses face each other across the street. Assessor records date several houses in this stretch to 1900 and 1906: 313, 331, 335, 339, and 347 Hearst all fall in that window. A note of caution. SF Planning's Property Information Map warns that build dates before 1906 may be unreliable because Assessor records were destroyed in the earthquake fire; surviving buildings were sometimes assigned a default year of 1900. Some of these houses may predate their official records. Which makes the facades themselves more trustworthy evidence than the numbers.
What the facades confirm is a shared vocabulary. Wood siding, shingle or clapboard, its grain catching afternoon light in a way stucco never does. Cottage scale. Visible wood trim around windows and along rooflines. Narrow-lot proportions consistent with builders fitting houses onto the flattest available ground as tightly as the grid allowed. No garages. These houses were built for a streetcar neighborhood, and the front of each lot gives its full width to the house and whatever small setback the builder allowed. There was no automobile to accommodate, so the facade did not accommodate one.
Walk south along the block and the cluster holds for several addresses. Then it breaks. In the 350s and 370s, at least two houses show stucco walls instead of wood siding, wider proportions, arched entries or simplified ornament. Assessor records date 351 Hearst to 1928 and 371 Hearst to 1925. They sit among neighbors built two decades earlier. Same block face. Same elevation. Same distance from Monterey.
The lots were available in 1900. Someone chose not to build on them until the mid-1920s. The Assessor record does not explain the gap. The facade makes it visible: stucco and arched entries look nothing like wood siding and cottage trim. Stand on the sidewalk and the block face reads as a timeline with two decades missing from the middle.
Edna Street, 1–38
One street west, the dominant era shifts. Assessor records date the low-numbered houses on Edna to a tight cluster: 7, 14, 15, 19, 25, and 38 Edna all fall between 1909 and 1914. A generation later than the earliest Hearst houses, but still pre-World War I. The difference registers at a glance. Bay windows push the building plane outward. Cornice lines grow more pronounced. The massing stretches to two stories with the vertical proportions and restrained classical ornament that San Francisco calls Edwardian: large double-hung windows, more formal trim than the cottages, a willingness to occupy the lot vertically that the Hearst builders did not share. Wood siding persists, but the vocabulary carries more confidence. Five years separates the earliest and latest build dates in the sampled group. Someone worked this block face in a concentrated burst during the years when post-earthquake demand was reshaping San Francisco's southern neighborhoods.
Then find the interruption. At 1 Edna, Assessor records show a build year of 1955. The lot existed in 1891 when the Land Company drew the grid. The 1910s builder worked the rest of this block face and left it alone. It stayed empty through the 1920s boom, through the Depression, through the war. Even a concentrated building boom could be remarkably selective. A dozen lots filled in five years while one sat untouched for four more decades. The 1955 house announces itself in simpler lines, different materials, no period ornament. It reads as what it is: a house from a different decade, filling a gap its neighbors left open.
Foerster Street, 2–142
One more street west, and the era shifts again. Foerster Street, named for Joost's attorney and Land Company investor Constantine Foerster, as the Sunnyside History Project records, received its houses a full generation after the grid was laid.
Assessor records date the low-numbered Foerster houses to the mid-1920s: 2 and 4 Foerster to 1925, 15 Foerster to 1927. Continue south past Joost Avenue into the 100 block and the dates hold. At 100, 112, 115, 130, 136, and 142 Foerster, build years fall between 1922 and 1925. The consistency is striking. Where Hearst showed a 1900s cluster interrupted by 1920s outliers, and Edna showed a tight 1910s burst with a 1950s straggler, Foerster presents an entire street face built in a single decade.
The facades confirm it. Stucco walls replace wood siding entirely. Their flat planes hold light evenly where clapboard would break it into horizontal bands of shadow. Arched entries and simplified Mediterranean ornament replace Edwardian bay windows and bracket trim. On the sloping lots, garages appear at street level, cut into the grade, with living space above. The houses sit above the walker, elevated on their own garages, the street dropping away downhill. The garage door is the first thing the facade presents. The car had arrived, and the facade had reorganized itself around the car's storage. Redfin's public-facts page for 4 Foerster, reproducing county records, describes it as a "Mediterranean bungalow." The term fits the block: modest in scale, stucco-clad, built for households that owned cars and wanted them off the street.
The thesis needs complicating at this point. Foerster's low-numbered houses sit roughly the same distance from Monterey Boulevard as Edna's and Hearst's. All three streets connect to the same transit corridor at roughly the same elevation. But Foerster filled in fifteen to twenty-five years later than Hearst and a decade later than Edna. The gradient is lateral. Cross from Hearst to Edna to Foerster and you cross from the 1900s to the 1910s to the 1920s without climbing appreciably. The subdivision filled in street by street, and the era of construction depended as much on when a builder got to that particular block face as on how steep the lots were. A 1914 Sanborn edition showing Foerster lots still empty while Hearst and Edna were already built up would confirm what the Assessor dates and the facades both suggest: the fill moved west, not up.
Foerster Street, 251
Continue south on Foerster past the 200 block. At 251 Foerster, Assessor records show a build year of 1948. More than two decades after the 1920s houses downhill, the pattern that held from 2 through 142 finally breaks. The lot was platted in 1891. The 1920s boom passed it over. Someone built on it three years after World War II ended. Fifty-seven years from subdivision to structure.
The 1948 date places 251 Foerster in the same late-fill category as 1 Edna. Both are lots that waited decades while their neighbors got built. Both sit at points where the grade steepens or the block face thins. In "Steep and Leftover," this publication argued that Sunnyside's smaller public spaces occupy terrain the 1891 grid couldn't profitably build on: lots too steep or too oddly shaped that eventually became parks and gardens instead of houses. The mid-century infill houses are the residential version of the same phenomenon. Lots where the grade was buildable but not attractive enough to draw a builder until the easier parcels were gone.
What the Facades Record
The evidence does not require expertise. A walker does not need to identify an Edwardian cornice to notice that the houses on Edna look nothing like the houses on Foerster, or that both differ entirely from the wood-sided cottages on Hearst. The materials change, the scale changes, the garages appear. Each shift marks a decade, and each decade left its signature in the facade details that a builder chose from the pattern books and construction norms of that particular moment.
What the facades record is how long a speculative wager took to fill a neighborhood. The Sunnyside Land Company platted 2,250 lots in 1891 on the city's southern slope. The streetcar was supposed to bring the buyers. The grid was supposed to give the lots their value. It took four decades and at least three distinct building eras for the lots to fill. The earliest builders worked the flattest ground nearest the transit line, using the wood-frame vocabulary of turn-of-the-century San Francisco. The 1910s brought Edwardian confidence to the next available streets. The 1920s boom brought stucco, Mediterranean ornament, and garages to the streets after that. The last lots waited until mid-century, when someone looked at an empty parcel between established neighbors and decided the slope was finally worth the trouble.
The interruptions are where the story gets most specific. The 1928 house among 1900s cottages on Hearst. The 1955 house among 1910s Edwardians on Edna. The 1948 house above the 1920s run on Foerster. Each one marks a lot where the documentary record shows decades of emptiness between the subdivision plat and the building permit, a gap long enough that the house that finally arrived belongs to a different era than its neighbors. They are the places where the clean narrative of orderly development breaks down into the actual, parcel-by-parcel process of a neighborhood filling in. The facades will tell anyone who counts how long each lot waited.
Field Reference: The Forty-Year Fill
Route: Hearst Ave at Monterey → Edna St → Foerster St to 200 block | ~1 mile | Moderate uphill on cross streets | 30–45 min at looking pace | Standard sidewalks throughout; steeper grades on Foerster above Joost
Era Prompts (carry these)
| Era | What to look for |
|---|---|
| Pre-1910 | Wood siding (shingle or clapboard), cottage scale, narrow lot, visible wood trim, no garage. Light catches the grain and horizontal shadow lines of the siding. |
| 1910s Edwardian | Bay windows, cornice line, two-story wood frame, restrained trim. More vertical than the cottages, more formal. |
| 1920s Mediterranean | Stucco walls (flat, even surface), arched entry or window, simplified ornament, garage cut into slope at street level. |
| 1940s–50s infill | Simpler massing, materials that break from neighbors, no period ornament. The house that doesn't match. |
Stops
Stop 1 — Hearst Avenue, 310s–340s South of Monterey on Hearst. Look for a run of wood-sided houses sharing cottage scale and narrow lots. No garages. Assessor dates: 1900–1906. Prediction: the block reads as a cluster from one era, built for a streetcar neighborhood.
Stop 2 — Hearst Avenue, 350s–370s Continue south on Hearst. Look for stucco walls and arched entries breaking the wood-siding pattern. Assessor dates: 1925–1928 among 1900s neighbors. Prediction: the material change alone identifies the newer houses. Two decades separate neighbors on the same block face.
Stop 3 — Edna Street, low numbers Walk west to Edna near Monterey. Look for bay windows, cornice details, two-story Edwardian massing. Assessor dates: 1909–1914. Then find the outlier: one house with simpler lines, no period trim. Assessor date: 1955. Prediction: the outlier's materials and scale announce a different decade. The 1910s builder skipped this lot.
Stop 4 — Foerster Street, low numbers to 100 block Walk west to Foerster, south from Monterey past Joost. Look for stucco walls, Mediterranean bungalow proportions, garages at street level on slope lots. Houses sit above the sidewalk on their garages. Assessor dates: 1922–1927. Prediction: the block face looks like one builder's decade. The consistency is the evidence.
Stop 5 — Foerster Street, 200 block Continue south on Foerster. Look for the 1920s run to break. At least one house shows mid-century character: simpler massing, different materials. Assessor date: 1948. Prediction: the interruption marks a lot that waited 57 years after the subdivision.
- The streetcar that started it: The Sunnyside History Project traces how Behrend Joost's San Francisco and San Mateo Electric Railway ran its first car through the subdivision on April 27, 1892, making Sunnyside's residential grid a transit bet before it was a neighborhood.
- Sanborn maps show the gaps: The Library of Congress holds public-domain Sanborn fire insurance maps from 1900 that recorded San Francisco at the parcel level, and comparing them to the 1914 edition would show exactly which Sunnyside lots were still empty a generation after the subdivision.
- Where the grid gave up: SF Planning's Property Information Map includes a glossary warning that pre-1906 build dates may be unreliable because Assessor records were destroyed in the earthquake fire, which means the oldest Sunnyside facades may be better evidence than their official dates.
- Sunnyside's RH-1 fine print: Redfin's county-record page for 142 Foerster reproduces RH-1 zoning language noting that "floor sizes and building styles vary, but tend to be uniform within tracts developed in distinct time periods," a planning-code observation this walk tests on foot.