In the Sydney metropolitan area, local councils often impose building height restrictions to preserve streetscape aesthetics and prevent overshadowing neighboring yards or causing visual disruption in the community. Adhering to these limitations often necessitates maintaining the existing structure’s height, leaving limited options for expansion.
For properties lacking expansive space, extending horizontally may not be feasible, leading to considerations of vertical expansion by creating a basement living area beneath the subfloor. This architectural endeavor demands meticulous planning to ensure adequate natural light, accessibility, and compliance with Building Codes of Australia standards.
Upon obtaining necessary approvals, a thorough site investigation, often conducted by a geotechnical engineer, becomes imperative to ascertain the site’s soil classification. This information is then utilized by a structural engineer to design suitable footings or underpinnings that enable safe excavation.
The challenges persist beyond design stages; a network of temporary support structures must be meticulously devised to ensure stability of the existing floor structure during and after construction. Steel posts and beams are frequently deployed to create a robust framework that bolsters the existing structure and reduces reliance on original footings. Subsequently, strategic underpinning of the perimeter footing occurs in stages to allow concrete to set and fortify a robust foundation surrounding the structure.
Once the underpinning process is completed, certain temporary beams may become permanent fixtures by linking them to the newly constructed underpinned footing, facilitating the removal of existing intermediate supports. Given that much of this work occurs in confined spaces, adhering to relevant safety standards and certifications for workers is paramount.
Builders or project managers must devise a construction methodology that ensures seamless workflow without compromising safety or hazard control measures. The intricate nature of these construction processes mandates careful planning, qualified personnel, and stringent safety protocols throughout the project.
