Creating New Types of System Families 157

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1 Creating New Types of System Families 157 Stair Types Stairs are complex building elements and require a deep understanding of local standards, rules, and requirements. Check the local building code requirements (minimum width, maximum height) to confirm that you re using the correct stairwell dimensions and proper headroom. Formulas for calculating stairs are based on common codes and ergonomics. These may have slight variations in different regions, based on local conditions. A number of parameters define the representation of stairs, including rules for risers, treads, and stringers; selection of construction techniques; and material used. All of these can be adjusted and made into types for use in your templates so that you always have the types of stairs that conform to the local building rules where you operate. Figure 5.12 illustrates different types of stairs that can be created in Revit. Figure 5.12 Stair types representing different construction approaches and material selections. Courtesy of Phil Read

2 158 Chapter 5 Customizing System Families and Project Settings in Your Template Properties of Stairs In the Type Properties dialog box for stairs, you can control the following properties: Calculation rules In the stair s Type Properties dialog box, in the Construction/Calculation rules, click the Edit button to open the calculation rules. To use the calculation functionality, select the option at the top of the Stair Calculator dialog box (see Figure 5.13). The calculation rule is based on the universal calculation formula that sets the value that should result depending on the size of the runs and risers. If this value can t be achieved, it should at least be within the minimum and maximum range you ve defined. Figure 5.13 Stair calculation options. Extend Below Base This field defines an offset between the base of the stair and the level where it starts. A positive value means the stair starts higher than its base level, and a negative value starts the stair below the base level. The top of the stair isn t affected by this parameter. This option is needed for conditions where the floor material demands that the stair start a bit higher or lower than the level. Monolithic Stair When this option is checked, it changes the stair into a monolithic form where the stringers, risers, and treads are treated as the same material. This is great for making concrete stairs. Landing Overlap This option is active only when the Underside of Winder option is selected (see the following explanation). Underside of Winder This option is available only with monolithic stairs and has two values: Smooth and Stepped. They represent the treatment of the underside of the stairs, as shown in Figure Break Symbol in Plan This parameter shows a break line in plan. If it s selected, the break symbol appears at the cut height of the stair. The part of the stair that is beyond the break symbol (above the cut plane of the view) is shown with special subcategories of stairs: Stairs Beyond Cut Line and Stringers Beyond Cut Line. Each can be assigned a different color and line type. This setting is unique to the rest of the graphics used for the stair. Figure 5.15 shows a stair with a visible break symbol (on the left), and the same stair with no break symbol (on the right).

3 Creating New Types of System Families 159 Figure 5.14 Monolithic stairs with Underside of Winder set to (A) Stepped and (B) Smooth. A B Figure 5.15 The same stair with and without the break-line graphic enabled. Text Size and Font When creating stairs, you can set automatic appearance of Up and Down text that indicates the direction of the stairs. The text size and font define the properties of that text. Material You can set different materials for various components of the stairs. When the Monolithic Stair option is selected, some of the options under Material will become grayed out as only one material will be considered for the entire stair. Minimum Tread Depth This parameter controls the depth of a tread. Once you place a stair in a project, you can set the Actual Tread Depth in the stair s instance parameters. If this value is less than the type property Minimum Tread Depth, Revit gives you an error message alerting you to the problem. Tread Thickness This parameter controls the thickness of each tread. Nosing Length As the name suggests, this parameter controls the length of a nosing in a stair. When this parameter has a value of 0, no nosing is applied to the stair. A positive value for this parameter results in a nosing being exposed on all treads. Nosing Profile This is where you can set the nosing profile that is used when Nosing Length has a positive value. You can create any custom Profile family for the nosing the Family Editor includes a Profile-Stair Nosing family template you need to use. Once you have the custom nosing family, you load it in the template (project) and associate it with a certain stair type. Apply Nosing Profile This determines where the nosing profile is placed relative to the tread. The available values are Front Only; Front and Left; Front and Right; and Front, Left, and Right. No Back option is available. Maximum Riser Height This field defines the maximum allowed value for a riser. Usually, this setting depends on regulations set in the local building code as well as the type of building. Begin with a Riser, End with a Riser These settings control the start and end of the stair and the connection with the landing.

4 160 Chapter 5 Customizing System Families and Project Settings in Your Template Riser Type There are three possible types: None, Straight, and Slanted. As shown in Figure 5.16, this is fairly self-explanatory for the riser. For the slanted type, you can t define the angle of the slope; that value is a result of the length of the tread and the profile of the nosing. Figure 5.16 Riser types: left to right, (A) no riser, (B) straight riser, (C) slanted rise with the value 1 (2cm) for nosing, (D) slanted riser with the value 1.5 (3cm) for nosing. A B C D Riser Thickness This value defines the thickness of the riser material. Riser to Tread Connection There are two options: Extend Riser behind Tread, as shown on the left, and Extend Tread under Riser, as shown on the right: Trim Stringers at Top This option controls how the stringer finishes its geometry at the top of the flight (see Figure 5.17). Figure 5.17 Trim stringer options. Do Not Trim: The stringer continues above the level. Match Level: The height of the stringer is coincident with the level. Match Landing Stringer: The top of the stringer is cut at a height that matches the landing stringer.

5 Creating New Types of System Families 161 Stringer Left/Right This setting provides three options for stringer geometry: None: No stringers applied to the stair. Closed: The stringers are placed on the sides of the stair. Open: The stringers are placed below the stair and are cut away by risers and treads. Note that if you have a stair with stringers and decide to change the type to Monolithic Stair, the stringer will disappear. Middle Stringers This option allows you to add one or more stringers below the stair. When more than one is added, they re evenly spaced. Thickness/Height of Stringers This option gives you dimensional control over the stringers. Open Stringer Offset This option is active only if the stringers are defined as open. This parameter controls the position of the stringer relative to the stair. Stringer Carriage Height This is the value between the stringer height and the treads. The larger the value, the deeper the stringer goes below the treads (the tread position stays the same). Landing Carriage Height This value controls the distance between the bottom of the landing and the bottom edge of the stringer. Door and Window Types Doors and windows are external families (RFA files) and are loaded into a project as needed. You should include door and window families that you use most frequently in your templates, and should remove content that you do not use.