Basement Lowering & Underpinning

Converting damp basements into dry and cozy living spaces. 

It’s a relatively straightforward matter for a company like Blueprint. The most common method of basement lowering with underpinning is the “Curb” system.  With this system, after excavating to the required depth, a concrete curb is added at the base of the foundation walls. All work is performed by our experts and overseen by geotechnical and structural engineers, as well as city inspectors. A basic underpin job will typically span 4-6 weeks and cost between $35,000-$50,000. The space can then be finished for anything from storage to a legal secondary dwelling unit.


  1. Initial consultation
  2. Consult with geo and structural engineers
  3. Apply for permits
  4. Seal all openings to main floor. Enlarge existing basement window to allow access from outside. This eliminates all traffic within the house during construction.
  5. Excavate & underpin foundation
  6. Install new drainage system and air gap membrane
  7. Repair/replace underground plumbing
  8. Add drainage layer and pour concrete floor
  9. Install basement new window(s)
  10. Clean up and dispose of all waste materials


  • Provides extra living space and adds value to your home
  • Add a legal secondary dwelling that generates extra income
  • Improves the living conditions of your house by providing better air flow and air quality with reduced dampness in the basement
  • Fortifies your existing foundation and creates a water control system that will keep your basement dry
  • Improves ground water drainage
  • Eliminate seepage of radon gas
  • 15-Year Transferable Warranty on all structural work

Approximate square feet of area to be lowered