Help Database

The General tab of the Room Specification dialog displays height information for the current room and the rooms above and below, if any exist.  The diagram on the right side of the dialog provides a view of the current room and the room below, if one exists.

This article offers a description of each value and how it relates to the others in the dialog.

 




Floor Height (A)

Floor Height (A) is the height of the top surface of the subfloor sheeting in the room.  This is the surface that you walk on before any final flooring is laid down in an actual building.

On Floor 1, the default value of Floor Height (A) is 0". This is very important because 0" is the starting value other heights are measured from, both in the Room Specification dialog and throughout your plan. You can change the Floor Height (A) value, but the new value is still measured from 0.

When you raise or lower Floor Height (A), several other height values in the dialog adjust to the change.  For example, if you raise the floor 12", its distance to the ceiling above decreases by this amount while its distance to the floor surface of the floor below increases; so:

• Ceiling height (B) decreases from 97 1/8" to 85 1/8".
  
  
• Lowered Ceiling (C) decreases from 90" to 78".
  
  
• Stem Wall Height (D) increases from 101 1/8" to 113 1/8".
  
  
• Ceiling below (F) increases from 97 1/8" to 109 1/8".
  
  

Notice that Floor Above Height (E), Platform Thickness (G) and Slab Thickness (H) are unaffected by changes made to the value of Floor Height (A).

Ceiling Height (B)

Ceiling Height (B) is the distance from Floor Height (A) to the bottom surface of the joists that support the ceiling of this room.  This is the surface sheetrock will be attached to, so this value is not the final, finished ceiling height but rather the rough framing height.

Because Ceiling Height (B) is the unfinished framing height, its value should be a bit more than the desired final ceiling height. We typically recommend adding 1 1/8".  For example, in a room where the final ceiling height will be 96" (8'), Ceiling Height (B) should be 97 1/8".  This additional 1 1/8" provides space for 1/2" for ceiling sheetrock, 1/2" for finished flooring, and 1/8" for any inconsistencies in framing.

When you raise or lower this value, only the Floor Above Height (E) adjusts to the change. 

• If, for example, Ceiling Height (B) is raised to 109 1/8", the Floor Above Height (E) increases to 121 1/8".
  
  
• All other values remain unchanged. 
  
  
  
  
  

Lowered Ceiling (C)

Lowered Ceiling (C) is the distance from Floor Height (A) to the bottom surface of the framing members that support a lowered ceiling.  As with Ceiling Height (B), this is a rough framing height rather than a final, finished height. 

Lowered Ceiling (C) allows you to create a lowered ceiling without affecting the top height of the floor platform of the floor above.  This is particularly important when living space is located above because it produces a single, level floor platform. You should enter a value in this field for nearly any room that has a ceiling that is lower than the other ceilings on its floor.

When you raise or lower this value, no other height values are affected.

Stem Wall Height (D)

Stem Wall Height (D) is the distance from the top of the stem wall footings to the bottom of the floor joists of the currently selected room.  This value includes the treated sill plate, or mud sill, which is 1 1/2" by default.

• When you raise or lower this value, no other height values are affected; the stem wall and footings simply extend further downward. 
  
  
• If a slab exists, the preview diagram shows a gap between the slab and the footing below if Stem Wall Height (D) is increased.
  
  
  
  
  

Floor Above Height (E)

Floor Above Height (E) is the distance from Floor Height (A) to the top surface of the subfloor sheeting of the room above.  This value is the sum of Ceiling Height (B) plus the platform thickness of the floor above.

When you raise or lower Floor Above Height (E), Ceiling Height (B) adjusts in the same manner. 

• If, for example, you raise Floor Above Height (E) from 109 1/8" to 121 1/8", Ceiling Height (B) will also increase 12" from 97 1/8" to 109 1/8".
  
  
• No other values are affected by changes to Floor Above Height (E).
  
  
  
  
  

Ceiling Below (F)

Ceiling Below (F) is measured from the the top surface of the slab floor below to the bottom surface of the floor joists of the currently selected room.  As with Ceiling Height (B), it is not the final, finished ceiling height but rather the rough framing height.

Unlike floor height values in this dialog, Ceiling Below (F) is not measured from Floor Height (A).  Instead, it is measured from the floor below. 

When you raise or lower Ceiling Below (F), Stem Wall Height (D) adjusts in the same manner.  For example, if you raise Ceiling Below (F) by 12" from 97 1/8" to 109 1/8":

• Stem Wall Height (D) increases 12" as well, from 101 1/8" to 113 1/8". 
  
  
• If a slab floor is present on the floor below, its height also decreases by the same amount.
  
  
• No other values are affected by changes to Ceiling Below (F).
  
  
  

Platform Thickness (G)

Platform Thickness (G) is the total thickness of the currently selected room's floor platform, consisting of the floor joists and subfloor sheeting.  This value cannot be changed on the General tab of the Room Specification dialog. Instead, change it by editing the thicknesses of the subfloor sheeting and/or the floor joists on either the Structure tab of the Room Specification dialog or in the Build Framing dialog.

If you increase or decrease Platform Thickness (G), Ceiling Below (F) adjusts in the opposite manner.  If, for example, you change the joists from 11 1/4" deep lumber to 14" I-joists:

• Platform Thickness (G) increases by 2 3/4" from 12" to 14 3/4".
  
  
• Ceiling Below (F) decreases by 2 3/4" from 97 1/8" to 94 3/8". 
  
  
• No other values are affected by changes to Platform Thickness (G).
  
  
  
  
  

Slab Thickness (H)

Slab Thickness (H) is the thickness of the slab floor below.  This value is specified in the Foundation Defaults dialog when the foundation level, or Floor 0, is generated.  To alter this value, either change  the Floor structure thickness of the room below or rebuild the entire foundation level.

If Slab Thickness (H) is increased or decreased, Stem Wall Height (D) adjusts in the same manner. 

• If you increase Slab Thickness (H) by 2" from 4" to 6", Stem Wall Height (D) also increases by 2" from 101 1/8" to 103 1/8". 
  
  
• No other values are affected by changes to Slab Thickness (H).