Because of the division of the lots, a majority of the houses faced north and south as opposed to east and west. As a result, rather than an equal division of sunlight, the southern facing buildings received constant sunlight and the northern facing buildings received no sunlight.
Edward T. Potter was the first to link the size of a New York building lot to the inability to produce a satisfactory product, arguing that it required houses too big for middle-class purposes and too small for well-designed multiple dwellings. Potter proposed the East-West gridiron block be modified by the inclusion of sixteen-foot-wide north-south mews, thereby creating small lots for which he planned 25x32 foot multi-unit houses. (11)
According to Potter:
"The peculiar evils
of the tenement-house system of the upper part of New York are not due
to the limited size or narrow width of the island on which New York is
built, as is generally supposed, nor are they due to overcrowding,
but to the inflexible depth of 100 feet each of the uptown lots [which]
is much larger than persons of moderate means can afford to build on…By
consequence, only very deep houses are built, in which only the rich can
afford to live with comfort; in which people of moderate means cannot live
with economy; and which, for the very poor, and even for mechanics and
artisans, become tenement-houses of a sort which can be lived in with neither
comfort, true economy, nor decency."(12)
Ernest Flagg, another tenement reform advocate and accomplished architect had similar views regarding the 25 by 100 feet lots.
"The greatest evil which ever befell New York City was the division of blocks into 25x100 feet. So true is this, that no other disaster can for a moment be compared with it. Fires, pestilence, and financial troubles are nothing in comparison, for from this division has arisen the New York system of tenement-houses, the worst curse which ever afflicted any great community…There is a crying need here for long stretches of grass, avenues of trees, and gardens, so placed that they can be conveniently reached by all the people."(13)
As mentioned before, tenement buildings evolved from row houses. The combination of a rapidly growing population with a constant amount of land forced landlords and building owners to build upon the current fortifications. The result was usually an additional floor or two on a row house and/or an extension into the backyard off the original row house or a completely separate new building.
AN IMAGE OF THE EVOLUTION OF TENEMENT APARTMENTS. AS THE YEARS
PASSED, ARCHITECTS BEGAN BUILDING FURTHER BACK, CREATING LESS LAND FOR
THE BACK YARD. (J)
The original Tenements had around eighteen rooms per floor and out of those eighteen, only the front two received any sunlight or ventilation.(14) Most of the rooms did not have any windows at all.