Final Answer:
The maximum allowable height of a new building in Washington D.C. is determined by the width of the adjacent street, plus 20 feet. As Pennsylvania Avenue is the widest street in the city, the maximum height would be the width of Pennsylvania Avenue plus 20 feet.
Step-by-step explanation:
According to the law, the height (H) of a new building is limited to the width (W) of the adjacent street plus 20 feet. Mathematically, this can be expressed as H = W + 20. Given that Pennsylvania Avenue is the widest street in Washington D.C., we use the width of Pennsylvania Avenue as W in the equation. If we denote the width of Pennsylvania Avenue as PA, then the maximum height (H_max) is calculated as follows: H_max = PA + 20.
Pennsylvania Avenue, being the widest street, sets the upper limit for building height in accordance with the law. For instance, if Pennsylvania Avenue has a width of 100 feet, the maximum allowable height for a new building along this street would be 100 feet + 20 feet = 120 feet. This ensures that the cityscape adheres to a proportional and aesthetically pleasing design while maintaining a balance between architectural development and urban planning.
In conclusion, the law establishes a straightforward formula linking building height to the width of the adjacent street, with Pennsylvania Avenue's width serving as the key determinant for the maximum allowable height in Washington D.C. This approach contributes to the city's architectural coherence and ensures that new constructions align with the established urban design guidelines.