Low Impact Substructures

"Connection to the earth"

Foundations are primarily concerned with supporting the building structural loads and the sites soil settlement over time. They shake hands with the earth and provide the necessary platform for super structures to rest on.

Foundation design strategies are chosen based on the existing conditions of the project site. They range in depth and have varying impacts on the site. Low impacts designs include the following design considerations:

1- Conserve natural areas

2- Minimize development impacts

3- Maintain site runoff rate and control small storms - Storm and Erosion Control Plans

4- Use integrated management practices (control volume and pollutant loads)

5- Implement pollution prevention, proper maintenance, and public education programs

"Back Bay Studio" by Peter Braithwaite Studio literally stands out when it comes to low impact foundations. It showcases a system that has minimal soil removal, uses minimal materials, and provides space for nature to exist.

The architectural program of the building is "driven by a desire to frame the coastal landscape and respect the sensitive ecosystem that exists on the site."

Additionally supported by the firm’s "commitment to create architecture that directly engages with the natural environment."

AI describe low impact foundation designs as ... a focus on minimizing environmental disruption and promoting "sustainability in construction. These designs are particularly relevant in areas sensitive to ecological changes and are often employed in green building practices. Key aspects according to the robots are: (Human notes in red)

• Environmental Preservation: Protects local ecosystems and reduces habitat destruction.

  • Minimal Top Soil Disturbance

  • Provides Water Management Considerations

    
    

• Regulatory Compliance: May help meet local environmental regulations and building codes.

  • Minimize Energy Intensity of Materials

  • Building near waterways and shores.

    
    

• Community Acceptance: Enhances public perception and support for sustainable building practices.

  
  

• Cost Efficiency: Often reduces construction costs through the use of less material and labor.

  • Site conditions, skilled labor access, and relevant technology available to the project will greatly effect each systems cost effectiveness.

    
    

Overall, low impact foundation designs represent a shift towards more sustainable construction methods, balancing the need for development with environmental stewardship. (Some robot, 2025)

• Post and Beam Foundations: Elevated structures that minimize ground contact, reducing disruption to the soil and vegetation.

  
  

• Pier Foundations: Use concrete or timber piers to support the building, allowing for natural drainage and minimal soil disturbance.

  
  

  Pier foundation" often focuses solely on the deep concrete piers themselves, while "post and beam" emphasizes the complete system including the beams that sit on top of the piers. 

  
  

• Floating Foundations: Designed to float on water heavy or unstable soil, reducing the need for deep excavation and soil removals.

  
  

• Earthbag / Biogenic Foundations: Utilizing bags filled with earth or other natural materials to create a stable and insulated foundation. Embanked Designs are often related to these strategies as well.