Final answer:
The elevation requirement for a small addition varies based on local building codes and environmental factors. Carefully calculated approximations are crucial in construction and structural engineering. Gravitational changes are considered in structural support for very tall buildings, though the effect is generally negligible.
Step-by-step explanation:
Understanding the Elevation of Additions
The question 'How high would a small (less than substantial) addition have to be elevated?' pertains to regulatory and engineering guidelines, and without specific codes or context, it is difficult to provide a precise figure. However, addressing this type of question generally involves considering building codes, flood elevation requirements, and the specific functional need of the addition. For instance, if the small addition is in a flood-prone area, local building codes might dictate that the structure be elevated above the base flood elevation level prescribed by FEMA.
As for the discussion regarding guesstimates and approximations, it showcases the importance of careful calculations in engineering and construction. When estimating figures such as height or mass, a rough estimate can be vastly different from a carefully calculated approximation. This approach is also relevant when considering the mass of air inside a house and understanding the impact of gravity on structural design.
Structural engineers indeed take into account changes in the gravitational constant (g) when designing support for very tall buildings, as the weight you feel can vary slightly depending on altitude. However, for most buildings, this effect is negligible and does not significantly impact structural design.