The San Mateo Highlands Eichler neighborhood sits on the ridges west of the city of San Mateo, above the Crystal Springs reservoirs. Unlike Palo Alto's flat Eichler tracts, it is built on hillsides. The National Register nomination for the Highlands' steel-framed X-100 house describes the neighborhood as a neighborhood of approximately 650 houses that Eichler Homes developed starting in 1955.
This post covers how the Highlands began, why Eichler built an experimental steel house there, the site and street plan, the architects linked to it, and what to keep in mind about hillside Eichlers and county rules. It is architecture and history, not a market report. For more of the area, see our San Mateo mid-century modern page.
A ridge-top tract outside the city
Despite the name, the Highlands is not inside the City of San Mateo. A San Mateo County environmental document describes the Highlands neighborhood as being "in an unincorporated area of San Mateo County," west of the city. In practice, county planning and building rules apply there, not city rules.
The X-100 nomination describes the setting from that house's lot on Lexington Avenue. The lot backs onto a downward-sloping hill of open space owned by the San Francisco Public Utilities Commission and kept as watershed. About a quarter mile west are the Lower and Upper Crystal Springs reservoirs, with the undeveloped hills of the coastal range beyond. Interstate 280 is barely visible from the house.
A published history of the neighborhood gives its edges as Polhemus Road on the east, Lexington Avenue and the watershed on the west, Laurel Hill Drive and Seneca Lane on the north, and Allegheny Way and Ticonderoga Drive on the south. A San Mateo County environmental document names Bunker Hill Drive and Yorktown Road among the streets inside the neighborhood. The same history dates construction from 1955 to 1964 and gives the ridge an elevation of 469 feet.
The count: about 650 houses, or more?
The X-100 nomination says approximately 650 houses, and the published history agrees with "approximately 650 or so," built from 1955 to 1964. A 2007 consultant's letter report included in a San Mateo County environmental document gives a different count: over 700 homes, built over 11 years from 1955 to 1965. That letter cites a website rather than a survey. No recorded tract list or county survey we read settles the count or the end date, so we give both.
The X-100: a steel house to draw a crowd
The X-100 was built to sell the neighborhood. Ned Eichler, Joseph Eichler's son, said the X-100 was his idea and that its purpose was to draw buyers to the then-remote Highlands. Neither Interstate 280 nor Highway 92 existed yet, so the area was hard to reach. The X-100 was one of the first homes built in the Highlands. It opened to the public on October 6, 1956, and drew what was said to be 150,000 visitors over three months.
Its design team, as listed in the nomination:
Architect: A. Quincy Jones of Jones & Emmons.
Landscape architect: Douglas Baylis, who the nomination says also designed landscapes for Eichler's San Mateo Highlands neighborhood.
Structural engineer: William R. Mason.
The house is 2,310 square feet, 56 feet wide and 64 feet deep, on an 80-by-100-foot lot. Its frame is exposed steel painted "deep-tone cinnamon," in the words of the grand-opening brochure. The roof is steel decking, originally covered in tar and gravel and now in sprayed polyurethane foam. Instead of an open-air atrium, it has two interior "living gardens" lit by skylights. The street side is a wall of concrete block, some laid to show their hollow cores as a screen.
The nomination treats the house as an experiment, quoting Eichler's brochure, which called it "a research laboratory" for new design ideas, materials and building methods. The features it lists include plastic laminate on interior surfaces for easy cleaning, electric spotlights in the skylights, movable track lighting, cooktops built into the dining table and the indoor gardens under skylights. At the front, a section of the steel roof decking folds down over the wall as a sunshade, a detail the nomination calls characteristic of Jones.
The experiment didn't carry over to the rest of the tract. Ned Eichler later said Eichler Homes built no more steel houses, citing cost and efficiency, and that the houses buyers wanted could be built more efficiently with wood frames. The nomination also notes that the two indoor planting spaces let Jones try a garden that could work in any climate, unlike the open-air atriums Eichler Homes would soon be known for.
According to the nomination, the X-100 is one of only two steel houses Eichler built, and he advised on a third. It is the one that survives intact. The house is listed on the National Register of Historic Places. Our Eichler X-100 page covers the house itself in more depth, and our Jones & Emmons page covers its architects.
Other architects tied to the Highlands
The published history names two other architects connected with the Highlands:
Pietro Belluschi, then dean of architecture at MIT, designed a two-story house there in 1958, published by a national magazine that October. The history says it still stands.
Aaron Green designed a planned subdivision for steep slopes at the north end of the Highlands in 1961. It included an "Arrow" model built on strong diagonals and a curvilinear model. Neither was built. See our Aaron Green page for his wider work.
Which firms designed the bulk of the Highlands' production houses isn't documented in the official sources we read. The X-100 nomination names Jones & Emmons for the X-100 only.
What makes a hillside Eichler different
Palo Alto's Eichler guidelines describe that city's tracts as flat. The Highlands isn't, and a few things follow from that:
Some original two-story houses. The published history says a couple of clusters of original two-story Eichlers were built where the sites required them. So a second story here isn't automatically a later addition. Check the permit history.
Views and the downslope side. Lots like the X-100's back onto watershed land. At the X-100, the all-glass rear wall opens to views across that land rather than to an enclosed yard.
Grading and drainage. On any sloped lot, have a licensed engineer or inspector look at drainage, retaining walls and the condition of the slab.
Change over time. At the time it was written, the published history counted more than 70 Highlands houses as drastically changed, about 60 of them with full, partial or attic second stories.
The same history reports that the original CC&Rs allowed architectural control but, according to a local source it quotes, hadn't been used in decades. It also says an early-2000s request to the county to rezone the Highlands against tall rebuilds and second-story additions failed. Because the area is unincorporated, confirm current zoning, design review and permit rules for any lot with San Mateo County Planning and Building. Ask an attorney about how the CC&Rs apply.
Frequently asked questions
How many Eichlers are in the San Mateo Highlands?
The X-100's National Register nomination says approximately 650 houses, developed by Eichler Homes starting in 1955. A 2007 consultant's report in a San Mateo County document says over 700, built from 1955 to 1965. We found no survey that settles it, so treat both as approximate.
Is the Highlands part of the City of San Mateo?
No. San Mateo County documents describe it as an unincorporated area west of the city. County planning and building rules apply.
Why did Eichler build the X-100 in the Highlands?
Ned Eichler said the goal was to attract buyers to the then-remote Highlands and to publicize Eichler's other neighborhoods. It opened on October 6, 1956, before Interstate 280 or Highway 92 existed.
Are there original two-story Eichlers in the Highlands?
Yes, according to a published history of the neighborhood, which says a couple of clusters were built for site conditions. Many other second stories are later additions, so check the permit record for any house.
Related reading
Wildfire Home Hardening for Hillside Mid-Century Homes in California
Post and Beam Earthquake Retrofit: Slab Homes, Programs and Checks
Eichler Architects: Who Designed Which Homes, Tract by Tract
Interested in the history or design of a San Mateo Highlands Eichler? Call or text the Boyenga Team at Compass at (408) 373-1660 or (650) 383-8606, or contact the Boyenga Team online.
