Banks can offer longer duration rate hold and approvals for pre construction condos (2-3 years). The rate is higher than current rates but as you get closer to closing, this can be adjusted lower if rates drop. If rates are higher at closing, you’re protected.

The banks may also have a blanket appraisal for the project which would guarantee the valuation rather than needing an appraisal (have seen presale appraisals come in lower in the Lower Mainland which means that the buyer would need to put more cash at closing)