Understanding How the Height of the Floor Relates to the Height of the Terrain


Reference Number: KB-00861
Last Modified: June 25, 2019

The information in this article applies to:

Home Designer Professional or Home Designer Architectural or Home Designer Suite



QUESTION

I've noticed that the rooms on Floor 1 of my plan have a floor height of 0", and that this is not the same height as the terrain. Why is that?


ANSWER

In the real world, floor platforms are nearly always built so that you step up into a building. There are a number of reasons for this, but perhaps the most important is to prevent the structure's framing from coming into contact with the terrain.

Over time, exposure to moisture in the soil can damage or even ruin untreated lumber in a framed floor platform or wall. For this reason, building codes in most areas require that floors be raised off the terrain.

Home Designer programs automatically raise the floor platform off the terrain for you. The amount that the floor is raised depends on the type of
foundation you have built in your plan: 

  • No foundation - The distance between the Default Floor Height of 0" and the terrain is equal to the depth of the default floor structure thickness for Floor 1.

  • Wall foundation with footings - The distance between the Default Floor Height of 0" and the terrain is equal to the depth of the default floor structure thickness for Floor 1, plus the default Sill Plate Height of the foundation, plus 6" (187 mm).

  • Monolithic slab foundation - The Default Floor Height of 0" is raised 8" (200  mm) above the terrain.

  • Pier and beam foundation* - The distance between Default Floor Height of 0" and the terrain is equal to the depth of the default floor structure thickness for Floor 1, plus the default Sill Plate Height of the foundation, plus 6" (187 mm).
    *Home Designer Pro Only


You can specify a different distance between the floor and the terrain if you wish.

To adjust the pad elevation

  1. Select the Terrain Perimeter, then click the Open Object edit button.


  2. On the General panel of the Terrain Specification dialog, remove the check from the Automatic box. 

    Uncheck the Automatic box to change the Subfloor Height Above Terrain value


  3. The Subfloor Height Above Terrain field becomes active so that you can type in the needed value, then click OK to apply the change.