How to Dig Down a Basement for Increased Headroom

Planning

• This process requires detailed planning and professional assistance. Architectural drawings, completed with input from a certified structural engineer and passed by your local building authority, are key. All permits must be in place before each stage of the process is begun. Experienced foundation contractors can guide you through each step of the build. Depending upon the scope of the project and the condition of your current basement and foundation, the process can cost from $50 per square foot to over $150 per square foot.

Evaluation

• The first step should always involve a site walk-about to examine the existing basement or crawlspace and gain an informed understanding of the structure of your home's foundation. Any existing problems such as cracking, settling or water intrusion must be noted and slated for remediation before dig-out begins. A consultation with a design professional will help you to design a full set of plans to guide the excavation and remediation process.

Excavation

• To minimize disruption, a good contractor will access your basement through an external entry hole cut through your existing foundation wall. Your current basement flooring may then be broken up and removed along with the yards of dirt required to reach the depth indicated in your dig-out plan. Structural supports, footings, walls and slabs will be poured as needed to ensure the structural stability of your home is maintained.

Finish Work

• Once the dig-out work is safely completed and local inspectors have signed off on the work, a finish contractor can begin the work of flooring, framing and drywalling the newly created living space. A homeowner experienced in the finishing process may choose to undertake this part of the job as a DIY endeavor or hire the work out as desired. Attention must be paid to building permits and mandated inspections by local authorities regardless of who has done the work.