Supplemental Regulations
Table 1 Maximum Permissible Sound Pressure Levels Measured re: 0.0002 dyne per cm2 | ||
|---|---|---|
Frequency Band (cycles per second) | Decibels | |
20 to 75 | 74 | |
76 to 150 | 62 | |
151 to 300 | 57 | |
301 to 600 | 51 | |
601 to 1,200 | 47 | |
1,201 to 2,400 | 42 | |
2,401 to 4,800 | 38 | |
4,801 to 10,000 | 35 | |
Table 2 Correction Factors | |||
|---|---|---|---|
Condition | Correction in Decibels | ||
On a site located within, contiguous to or across the street from any property in an R District | Minus 5 | ||
Sound levels emitted between the hours of 10:00 p.m. and 7:00 a.m. | Minus 5 | ||
Sound of an impulsive character (for example, hammering) | Minus 5 | ||
Sound of periodic character (for example, hum or screech) | Minus 5 | ||
Sound source operated less than: | |||
20% in any one-hour period | Plus 5* | ||
5% in any one-hour period | Plus 10* | ||
1% in any one-hour period | Plus 15* | ||
* | Apply only one of these corrections. |
Building Footprint (square feet) | Requirement | |
|---|---|---|
1,000 to 30,000 | 1 tree for each 1,000 square feet of building footprint | |
30,001 to 75,000 | A minimum of 30 trees, plus 1 tree for each 3,000 square feet of building footprint in excess of 30,000 square feet | |
Over 75,000 | A minimum of 45 trees, plus 1 tree for each 5,000 square feet of building footprint over 75,000 square feet |
Number of Multifamily Dwellings | Required Trees | |
|---|---|---|
First 25 dwelling units | 1 tree for each dwelling unit | |
26 to 100 dwelling units | 25 trees, plus 1 tree for each 2 dwelling units in excess of 25 dwelling units | |
101 to 200 dwelling units | 62 trees, plus 1 tree for each 3 dwelling units in excess of 100 dwelling units | |
201 or more dwelling units | 95 trees, plus 1 tree for each 4 dwelling units in excess of 200 dwelling units |
Size of Lot (square feet) | Maximum Floor Area of Accessory Structure (square feet) | |
|---|---|---|
Up to 21,780 | 500 | |
21,780 to 43,560 | 1,000 | |
Over 43,560 | 1,500 |
Permitted Increase (dBA) | Duration of Increase (minutes)* | |
|---|---|---|
5 | 15 | |
10 | 5 | |
15 | 1 | |
20 | 1 |
* | Cumulative minutes during any one hour. |
Supplemental Regulations
Table 1 Maximum Permissible Sound Pressure Levels Measured re: 0.0002 dyne per cm2 | ||
|---|---|---|
Frequency Band (cycles per second) | Decibels | |
20 to 75 | 74 | |
76 to 150 | 62 | |
151 to 300 | 57 | |
301 to 600 | 51 | |
601 to 1,200 | 47 | |
1,201 to 2,400 | 42 | |
2,401 to 4,800 | 38 | |
4,801 to 10,000 | 35 | |
Table 2 Correction Factors | |||
|---|---|---|---|
Condition | Correction in Decibels | ||
On a site located within, contiguous to or across the street from any property in an R District | Minus 5 | ||
Sound levels emitted between the hours of 10:00 p.m. and 7:00 a.m. | Minus 5 | ||
Sound of an impulsive character (for example, hammering) | Minus 5 | ||
Sound of periodic character (for example, hum or screech) | Minus 5 | ||
Sound source operated less than: | |||
20% in any one-hour period | Plus 5* | ||
5% in any one-hour period | Plus 10* | ||
1% in any one-hour period | Plus 15* | ||
* | Apply only one of these corrections. |
Building Footprint (square feet) | Requirement | |
|---|---|---|
1,000 to 30,000 | 1 tree for each 1,000 square feet of building footprint | |
30,001 to 75,000 | A minimum of 30 trees, plus 1 tree for each 3,000 square feet of building footprint in excess of 30,000 square feet | |
Over 75,000 | A minimum of 45 trees, plus 1 tree for each 5,000 square feet of building footprint over 75,000 square feet |
Number of Multifamily Dwellings | Required Trees | |
|---|---|---|
First 25 dwelling units | 1 tree for each dwelling unit | |
26 to 100 dwelling units | 25 trees, plus 1 tree for each 2 dwelling units in excess of 25 dwelling units | |
101 to 200 dwelling units | 62 trees, plus 1 tree for each 3 dwelling units in excess of 100 dwelling units | |
201 or more dwelling units | 95 trees, plus 1 tree for each 4 dwelling units in excess of 200 dwelling units |
Size of Lot (square feet) | Maximum Floor Area of Accessory Structure (square feet) | |
|---|---|---|
Up to 21,780 | 500 | |
21,780 to 43,560 | 1,000 | |
Over 43,560 | 1,500 |
Permitted Increase (dBA) | Duration of Increase (minutes)* | |
|---|---|---|
5 | 15 | |
10 | 5 | |
15 | 1 | |
20 | 1 |
* | Cumulative minutes during any one hour. |