True Divided Light (TDL) vs. Simulated Divided Light (SDL)

True Divided Light Windows vs. Simulated Divided Light Windows

Feature True Divided Light (TDL) Simulated Divided Light (SDL)
Glass Construction Multiple individual panes of glass separated by muntins Single pane of glass with interior/exterior grids and spacer bar
Historical Accuracy Most historically authentic; often required in preservation districts Designed to mimic the look of traditional windows
Energy Efficiency Less efficient due to multiple panes with potential air gaps Highly energy-efficient with insulated glass and low-E coatings
Cost Higher due to materials and craftsmanship More affordable while offering a similar look
Cleaning & Maintenance Difficult to clean between panes; more upkeep needed Easier to clean with solid glass surface
Customizability Fully customizable muntin layout, glass type, and sash style Offers flexibility but limited by manufacturing process
Best For Historic renovations requiring exact match; preservation requirements Homeowners wanting a traditional look with modern performance
Appearance Authentic divided glass with depth and light refraction Simulated depth using spacer bars and applied grids
Common in Pre-1940s homes, restoration projects, historic districts like Hyde Park Newer builds or retrofits in Brookside, Prairie Village, and Westport

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True Divided Light Windows
Simulated Divided Light Windows