RECORD OF TESTIMONY AND STATEMENTS IN RELATION TO 185 



NECESSITY FOR DISTRICTING PLAN 



co-ordinated with those on the lot considered. Then if this building is 

 also 60 feet high, our tenement, which is once the width of the street if 

 built on a 60-foot street is served" by a court only half as large as that con- 

 templated by the law. In that event the direct illumination obtained from 

 the sky at the bottom of the center portion of the side wall is only 2.1 foot 

 candles while that at the center portion of the end wall is only 3.8 foot 

 candles. The street facade, assuming the street to be uniformly improved 

 with 60-foot buildings, receives at the bottom 128 foot candles. In other 

 words the direct illumination received at the bottom of the court is only 

 from one and one-half to three per cent of that received at the correspond- 

 ing point on the front facade of the tenement. 



Assume that the complementary court 12 feet by 24 feet is provided on 

 the adjoining lot, making a combined court 24 feet by 24 feet, the direct 

 illumination at the bottom of the wall would still be only 7.5 candles or 5.8 

 per cent of that obtained at the bottom of the street facade. 



The direct daylight illumination obtained in an inner court the length 

 of which is twice its width and the height of which is expressed in multiples 

 of its width is stated in the following table. The illumination given is that 

 received on a vertical surface at the bottom of the court wall half way be- 

 tween its ends. 



Illumination in Foot Candles 

 Height in Terms of 

 Width of Court 



1 : 



2 



3 



4 



5 



6 



Daylight entering windows 



The quantity of daylight entering an ordinary front window is between 

 40 and 75 per cent of that falling on the street faGade. From 25 to 60 per 

 cent of the daylight received by the facade is cut off from penetrating into 

 the rooms by the frame in which the window is set. This is the situation 

 with an unobstructed window. If there are buildings on the other side of 

 the street opposite the window the percentage of daylight received by the 

 room is, of course, much smaller, the exact amount depending upon the 

 height of the obstructing buildings. 



Barring obstructions, it is the size of a window with reference to the 

 thickness of the wall in which it is set that determines the amount of daylight 

 admitted into a room. A small window in a thick wall admits propor- 

 tionately less daylight than a large window in a thick wall. Thus an unob- 

 structed window two feet wide and four feet high set in a wall one foot 

 thick has 53 per cent of its light cut off by the thickness of the wall while 

 a window twice as large, four feet wide and four feet high, set in a wall one 

 foot thick, has only 40 per cent of its light cut off by the thickness of the 

 wall. For an unobstructed window of a given size the proportion of the 

 daylight received which passes through the window diminishes with the 









On End Wall 



Or 



i Side Wall 



103.9 





109.9 



34.3 





25.9 



14.2 





9.0 



7.0 





4.0 



3.8 





2.1 



2.3 





1.2 



