Whenever possible sill and threshold conditions are developed to create the minimal transition between interior and exterior walking surfaces. The majority of our projects have cut or cast stone threshold treatments. Extruded sill solutions can be introduced if needed.
Outswing doors typically have a step down from interior to exterior. Inswing door sills typically need a raised threshold to prevent water blowing in. Sliding doors have top hung floor guides that are flush to finish floor and offer the most seamless transition while still acting as a water return. Bottom rolling sliding doors have a water return guide track that sits a subtle 3/16" above finish floor for a near flush transition.
Whenever weather exposure is a concern, drain slots should be added to the inswing sill designs. Extreme weather environments need more extreme measures and coordination with waterproofing consultants.