Why is it important to accurately model the land features of your project site with a toposurface?
The structural aspects of the building, specifically on the lower level, are greatly affected. Because the structure is sitting on the hillside, a portion of the lower level ends up embedded in the hill, while the other corners can sit on grade. Therefore, specific retaining walls must be designed to act as the barrier between the house and the hill/soil that will press against the building. The need for the structural retaining wall will also affect the architectural design of the lower floor. To more efficiently use material, the lower floor automatically uses concrete walls that can be reinforced to act as the retaining wall. This makes placing architectural elements like windows more difficult.
When designing a project...
- Should the building adapt to the terrain?
- Or, should you adapt the terrain to the building?
The building should adapt to the terrain, as this is likely more cost-efficient for the stakeholders. For example, if the structure is on a hill, it may cost more money to excavate the hill to make a flat foundation. Additionally, the excavation is likely going to spread beyond the immediate footprint of the building, such that a path can be built from the house. If the building is adapted to the terrain, no major excavations may need to be done. However, like in the hillside house built in this module, the lower floor may have architectural limitations due to structural requirements. Houses build in complicated terrains will likely require different retaining structures, which will also add to the cost of the structure.
Why do stairs follow specific proportions with a set relationship between the tread length and riser height?
The stairs have specific proportions mainly for ADA reasons. The tread length needs to be a specific dimension to make sure there is enough area to step on for people of all sizes. The riser height should also be standardized across stairs. Muscle memory will likely dictate people’s experience with climbing stairs, and a taller riser height will interrupt that, making the stairs feel steep and unstable. By modeling it in Revit, the stairs are ensured to have enough space in the overall building. When there is less space than required, the stairs cannot fit, and may force the installer to change the riser height.