The ultimate goal is a dry internal environment in your basement or cellar. However, any walls in direct contact with the earth may experience hydrostatic water pressure. You, therefore, need to effectively deal with this pressure to stop water from entering the structure. You can tank the basement structure using conventional barrier tanking; however, any slight defect will be exploited if tanking is subjected to sufficient hydrostatic pressure. Also, barrier tanking is generally non-maintainable, increasing the risk of failure over time. A complete external waterproofing system, including an internal cavity membrane, is the best option for mitigating risk.  Environment It is important to consider your environment when installing a new-build basement. This will require a professional who can analyse the soil type, ground drainage, the presence of any potential contaminants (PermaSEAL Geodrain cavity drain membrane is resistant to all chemicals normally found in the ground), and the height of the water table. These should be considered in light of the intended use of your basement. External Waterproofing Systems With external waterproofing systems, we recommend combining a primary and secondary waterproofing system along with a priming stage. Priming The first step in external waterproofing in most cases is priming. Priming involves applying a specially-designed spray such as Kiesel Waterproofing Primer or Kiesol MB Primer to the external structure. This forces the masonry pores to narrow, creating a water-repellent surface. Primers are also designed to bond with the waterproof coating used in the primary waterproofing stage. Primary Waterproofing  Primary waterproofing involves applying a waterproof material directly to the external wall. It would be best to waterproof the substrate with a waterproofing compound such as Multi Tight. These specially-designed coatings have a high compression strength and are watertight even under aggressive pressure.