How to Configure Drawing Properties for Accurate Glass in Sash and Direct Glazed Unit Sizes

Introduction

Setting up sectional details in order to get accurate glass sizes is not self explanatory. This document lists DrawingBoard properties involved and explains the logic behind actual size calculation.

Actual Size Calculation for Glass in Sash

System uses the following information when calculating actual glass sizes for all types of sashes (sliding, casement, door, …)

The system uses 3 key details for the calculation.

Glass sightline is calculated by DrawingBoard using overall frame sizes and sectional details configured.
Glazing rebate width is set on the Default Value page. There are 5 defaults which the system uses based on drawing details. This value is the amount taken off from sash stile to accommodate glass unit and tolerance.
Glazing tolerance is set on Default Value page too, providing 4 defaults. This value is the gap between glazing rebate and edge of glass unit on one side of the glass.

Based on glazing rebate width and glazing tolerance the amount of glass hidden in rebate is calculated.

glass hidden in rebate = glazing rebate width - glazing tolerance

Using these details the actual sizes for the glass is calculated as follows

glass actual width = sightline width + glass hidden in rebate * 2

glass actual height = sightline height + glass hidden in rebate * 2

Actual Size Calculation for Direct Glazed Units

System uses the following information when calculating actual glass sizes for Direct Glazed Units (DirGUs)

The system uses 4 key details for the calculation.

DirGU stop size is set on the Default Value page. This value is the size of the stop around the direct glazed unit. Distance between profiled frame and glass sightline. If this is not set, system will use 15mm

2. Glass sightline is calculated by DrawingBoard as follows

sightline width = overall frame width - 2 * (profiled frame jamb + DirGU stop size)

3. Glazing rebate width is set on the Default Value page. There are 5 defaults which the system uses based on drawing details.

4. Glazing tolerance for DirGUs is set on Default Value page too, providing 4 defaults. This value is the gap between glazing rebate and edge of glass unit on one side of the glass.

Based on glazing rebate width and glazing tolerance the amount of glass hidden in rebate is calculated.

glass hidden in rebate = glazing rebate width - glazing tolerance

Using these details the actual sizes for the glass is calculated as follows

glass actual width = sightline width + glass hidden in rebate * 2

glass actual height = sightline height + glass hidden in rebate * 2

Rails for Direct Glazed Unit

Direct glazed units can also have top and bottom rails.

If an edge of a DirGU touches a rail, then, for that edge, the system will use sash rebate and tolerance.

If the edge of a DirGU touches the frame, not a rail, then the system will use DirGU rebate and tolerance.

Glazing Bar (GB)

integrate supports two types of glazing bars.

Bonded-on or Astragal bars
Georgian or true bars

	Single glazing	Double and triple glazing
Bonded-on bars	Rare, mainly used with laminated glass	Most common for sealed units
Georgian bars	Traditional window manugacturing	Individual sealed units, called heritage units in integrate

Bonded-on bars do not affect glass sizes.

For Georgian bars there are a few things to note. When actual sizes are calculated for individual glass units, the system checks all 4 edges of the glass (top, left, bottom, right).

If an edge is touching the sash (stile, head, bottom rail) the system calculates glass hidden in rebate as per Actual Size Calculation for Glass in Sash section above.

However, if an edge is touching a Georgian glazing bar, the calculation is the following.

GB glazing rebate width = GB width - tail / 2

Assuming the same glazing tolerance around the 4 edges of the glass the calculation is

glass hidden in rebate = GB glazing rebate width - glazing tolerance

This means, that the system may add different amount to the 4 sides of the glass depending on the Georgian glazing bar details.