Period of Significance

The Period of Significance is the historic time period defined for each HPOZ — typically the period during which the majority of construction in the area occurred. Adopted Preservation Plans phrase it consistently: “The historic period of significance of the HPOZ is usually the time period in which the majority of construction in the area occurred.”

Each district has its own Period. It is set during the establishment of the HPOZ when the Historic Resources Survey is prepared and certified by the Cultural Heritage Commission, and is incorporated by reference into the adopted Preservation Plan.

The Period of Significance informs which structures in a district are classified as Contributing. It is an input the Survey uses to determine classification. It is not, by itself, the Survey, and it does not by itself produce a classification. Two practical points follow.

The Survey, not the Period, is the binding classification document. A property’s Contributing or Non-Contributing status is recorded in the Survey. The Period informs how the Survey was constructed; it does not override what the Survey records. Where the Period and the Survey designation seem inconsistent on a specific parcel, the Survey controls.

Construction date alone does not produce classification. A structure built within the Period generally retains a presumption of Contributing status, but only if it also retains elements that identify it as belonging to the period. A structure built within the Period that has been altered beyond reasonable reversal can still be classified Non-Contributing. A structure built outside the Period can be classified Contributing if it is architecturally compatible with the district or historic in its own right. The Period is a starting input, not the answer.

The Period is determined by qualified historic preservation professionals during the Survey process, drawing on the historic context statement prepared for the district. The context statement identifies the historical development patterns that define the neighborhood — the boom decades, the dominant architectural movements, the social and economic forces that produced the built fabric. The Period brackets the years during which that development substantially occurred.

Some Periods are tightly bounded around a single development era. Others span many decades to capture multiple growth waves. The choice reflects the underlying historic narrative of each district, not a procedural default.

The variation across districts is significant. The table below shows Periods of Significance drawn from the district Preservation Plans reviewed for this entry. Periods range from a two-year window to a seventy-five-year span.

The variation has practical consequences. A 1955 California Ranch could carry presumptive Contributing status in Windsor Square (Period extends to 1965) or in Hancock Park (Period extends to 1956). The same construction date dropped into Spaulding Square or Hollywood Grove would fall outside the Period and most likely receive a Non-Contributing classification on construction date alone — though the Survey is the document that actually makes the call.

Adopted Preservation Plans describe the relationship clearly: a Contributing structure is generally one built within the Period of Significance that retains elements identifying it as belonging to that period. A Non-Contributing structure either does not date from the Period, does date from it but has been altered to the point that it no longer retains those identifying elements, sits on a vacant lot, or was built without permits.

Two consequences flow from this for owners and design teams.

The Period is a screening tool, not a determination. Construction date can be sorted into “in the Period” or “outside the Period” easily. The Survey then applies the dominant classification framework — built-within-Period structures are typically Contributing if they retain identifying features, and Non-Contributing if they do not. The screening narrows the analysis; the Survey does the determination.

The Period is also a design-guideline anchor. The dominant historic styles of the Period inform the design guidelines applicable to alterations on Contributing properties and to infill on Non-Contributing or vacant lots. This is why the same proposed Spanish Colonial Revival is treated differently in Hancock Park (where Spanish Colonial Revival is among the dominant Period styles) than in a district with a different stylistic concentration.

The Period is not a hard cutoff for Contributing classification. Per language drawn from adopted Preservation Plans: “In some instances, structures that are compatible with the architecture of that period or that are historic in their own right, but were built outside of the Period of Significance of the district, will also be Contributing.”

Two scenarios may produce an outside-the-Period Contributor:

• Architectural compatibility. A house built shortly after the Period closes, in a style consistent with the dominant Period styles, that completes the streetscape rather than disrupting it. The Survey may designate the property Contributing on compatibility grounds.
• Independent historic significance. A property historic in its own right — for an architect, a resident, a historical event — designated Contributing on individual significance even if the construction date falls outside the Period.

Owners cannot self-determine compatibility or independent significance. The Survey makes the call when it is conducted, and an existing Survey designation can be amended only through the OHR-led amendment process.

Source: Citywide HPOZ Ordinance (LAMC §12.20.3) and Division 13B.8 (Historic Preservation), Chapter 1A LAMC. Periods of Significance set in each district’s certified Historic Resources Survey and adopted Preservation Plan. District-specific Periods quoted directly from the adopted Preservation Plans reviewed for this entry: El Sereno – Berkshire Craftsman District (1905–1941), 52nd Place Tifal Brothers Tract (1911–1914), Carthay Square (1924–1949), Spaulding Square (1916–1926), Hancock Park (1920–1956), Hollywood Grove (1905–1939), Jefferson Park (1888–1951), Banning Park (1927–1967), Highland Park-Garvanza (1886–1961), Windsor Square (1906–1965), Gregory Ain Mar Vista Tract (1946–1948), Adams-Normandie (late 19th century to 1930s), Balboa Highlands (1962–1964).