Making Good Use of the Attic

Start off by drawing out the walls of your first floor.  In this case I will make my home 20' wide by 30' deep.  At this point you will want to save your work as we will be creating the 2nd floor next and 3DHA requires you save the first floor before creating the 2nd.

Next, let's create the second floor from the first.  Single-Click (click) Window in the Main Menu and then click Show Floors in the drop down menu.  The Show Floors dialog box (dlgbx) will open. Click the Build button under 2nd and the New Working Plan dlgbx will open. Choose "Derive new 2nd floor from the 1st floor plan" and click OK.  You will return to the Show Floors dlgbx. Click OK and your 2nd floor will be created.  You will notice by the .pl2 in your screen Title Bar that you are now on the 2nd floor.

At his point you will want to set the defaults for the entire 2nd floor.  Double-Click the only room that makes up the second floor and the Room Specification dialog box will open.  You will want to remove the check mark in the "Ceiling over this room" check box because we are going to use the area under the roof for our head room on the second floor.  Next, click the Floor Defaults button in order to open the Floor Defaults dlgbx.  I have shown only the portion of this dialog box that we will be changing.  We will be changing the Ceiling Height from the default of 96 inches to 16 inches.  Since we will not actually be using a ceiling on this floor, (we removed the "Ceiling over this room" check mark), this 16 inches represents the distance the hip walls will rise from the floor before creating the top plates and starting the roof up toward the roof ridge.  This will be more evident in our final cross section views.
Now we want to make Gable walls at the front and rear of our home.  That will give us much more room on the second floor.  So choose the roof tool bar and the Roof Section at Wall tool should be selected by default.  So single-click the rear wall and the Roof Section at Wall dialog box will open.  Check Full Gable Wall and click OK.  Do the same for the front wall.

Now draw in the two walls that will make up the sides of our room.  They run from front to rear and should be placed about 4' from the outer walls.  See example.  In our example, we are going to use these walls to separate the room from the attic space. You can use that space if you want.  BUT.....you will have to include these two walls.  Just make them invisible if you don't want them to show.  We won't make them invisible in our example.

Let's build a roof. Click on the Roof tool bar and then click the Build Roof tool. The Build Roof dlgbx will open.  Change the Pitch to 12 in 12 and click OK.  The roof should be created and you should see it's outline.
Before we view our results, add a Full cabinet to the room as shown in the example. Choose the Cabinet tool bar and the Full Cabinet tool.  Click somewhere in the room.  This cabinet is 7' tall and will give us an idea of how much head room we will have.

Now view the cross section by selecting the View tool bar and the Cross Section tool. (see bottom of example.) Drag the cursor from front to rear starting inside the room.  (see red arrow in example.) You should see something like in the example. 

From this cross section you can see that the 7' tall cabinet will not fit flush up against the side wall.  It shows that the roof will not give full height head room in the areas against those walls. But this is no problem as the main walking space, generally in the center of the room is more than enough.  Beds, dressers, and other furniture will likely use the space under the roof that falls below 7'.  You can see that this gives you a generous 12' x 30' room that you would not have if you did not create this attic room.  You will also be able to use the remaining attic space on both sides for storage.
Back in Plan View, add a window and then look at your room in Full Camera View.  It should look something like this example. 

This lesson should give you an understanding about how the Ceiling Height refers to the height above the floor where the top plate of your walls will be placed.  The roof above this room can be raised or lowered by changing the Ceiling Height value.

As stated in the lesson previously, you can make one or both of the side walls invisible.  But remember, those walls need to be included or your plan will not be created as expected.  You can see in the next example that the side walls have been made invisible.  The Plan Camera View makes the room look larger, but you will have problems with the low head room near the walls.