HEIGHT DISTRICTS 33 



quarter times district the setback rule is one to two and one-half ; in the 

 one and one-half times district 1 to 3 ; in the two times district 1 to 4 and 

 in the two and one-half times district 1 to 5. This secures, except for 

 streets less than 50 feet or more than 100 feet in width, a constant ratio 

 between the height of the street wall at any point and its distance from the 

 center of the street at such height. In other words, no part of the building 

 may be carried above a plane formed by the intersection of a horizontal 

 line through the center of the street and a line at right angles thereto drawn 

 through the limiting height at the street line. This will permit greater 

 freedom of building construction than a flat limitation of height and at the 

 same time will preserve a uniform angle of light down into the center of 

 the street. 



At the intersection of a narrower with a wider street the height limit 

 on the wider street governs for 100 feet back on the narrower street if such 

 narrower street is not more than 60 feet wide. 1 For each one foot 

 by which such narrower street exceeds 60 feet the influence of the height 

 limit on the wider street extends one and one-half feet further back on 

 the narrower street. Thus, if the narrower street is 80 feet wide the 

 height limit of the wider street will extend back 130 feet on such 80-foot 

 street. This will apply to all buildings within the 130-fo'ot stretch whether 

 they front on the wider or the narrower street. The distance back on the 

 side street that the height limit of the wider street should go depends on 

 light conditions on the narrower street as influenced by its intersection with 

 the wider street and by the width of such narrower street as compared with 

 that of the wider street. Both of these factors are taken into consideration 

 in the rule applied. 



As an exception to the general height and setback rule special regula- 

 tions are provided for dormers and towers. Above the height limit on the 

 street line dormers and head-houses may, with the approval of the building 

 superintendent, be erected on the street line provided their aggregate front- 

 age length on the street line be not greater than 60 per cent, of the street 

 frontage and provided that such percentage shall be reduced by one for 

 every foot of height above the height limit on the street line. This will 

 permit the erection of one large dormer or a number of small dormers in 

 a mansard above the height limit on the street line. On a 100-foot front- 

 age' this will mean that the dormer on the street line at the height limit can 

 be 60 feet wide ; but at a height of 10 feet above the height limit the dormer 

 can be only 50 feet wide ; at 20 feet, 40 feet wide and so on until at 60 

 feet of height the width of the dormer is reduced to a point. (See Figure 

 144.) It is also provided that the percentage of the total frontage to be 

 devoted to dormers may be increased by one for each four inches that such 

 dormers are set back from the street line. 2 On a 100-foot frontage this will 



1 This proposed rule is modified in important particulars by sec. 9, par. (b) of 

 the Resolution of July 16, 1916. See page 237. 



*This proposed additional percentage allowance is omitted in the Resolution 

 adopted. See sec. 9, par. (c), page 237. 



