A similar case exists on the south side of Garfield Place, in the row beginning at the southeast corner of 7th Avenue:
Here, what appears to be a row of nine identical buildings is split between the four easterly houses, which are included in the Park Slope Historic District, and the five westerly houses, which are not.
The Park Slope Historic District's Designation Report includes a description of the first group, #214-220 Garfield Place, four neo-Grec houses built in 1884 by owner-builders Martin & Lee of 440 Clermont Avenue:
The same builders erected some of the houses in President Street just below 7th Avenue.
Citations from the American Architect and Building News confirm what the eye can plainly see, which is that Martin & Lee built the rest of the Garfield Place row to the 7th Avenue corner as well.
Interestingly, however, the buildings were apparently built in small groups of two or three at a time. #212 & 210 Garfield Place, immediately outside the current historic district (the boundary runs between #214 and 212 Garfield Place), were apparently built in 1884:
#208-204 Garfield Place, however -- the three buildings on the corner of 7th Avenue -- were apparently built nearly two years later, in 1886:
#204 Garfield Place, at the corner of 7th Avenue, was later retrofit for commercial space at the basement and parlor floors. That the commercial conversion was very early is reflected in the cast-iron pilasters framing the projecting window at the parlor level, which look nearly as old as the original cast iron on many 7th Avenue mixed-use buildings:
Although all nine buildings in the entire row by Martin & Lee are otherwise identical, there is one extremely slight difference in the console brackets from 1884 and 1886:
So once again we have a case of an identical row by the same builder, split between houses inside and outside the historic district. Once again, five houses are excluded, each approximately 20' wide, for a total of 100', the depth of a standard building lot in Brooklyn. It is as if the 7th Avenue frontage were deliberately excluded from the original 1973 Park Slope Historic District, to allow large development parcels to be assembled and bulldozed for larger buildings. Is this another case in which politics impact landmarking decisions?
Finally, for the "completists" out there (you know who you are)... the current Park Slope Historic District Designation Report (p. 59) omits the builder for the 5-building group 230-238 Garfield Place, inside the current historic district. We have discovered that it is, again, Martin & Lee:
"Building Intelligence; Houses; Brooklyn, N. Y.," AABN vol. 32, no. 804 (May 23, 1891): p. xviii.