Each archetype house can be configured seven different ways to satisfy recommendations in Table 7 of the National WUI Guide. Table 20 shows the combinations of construction class and priority zones, along with a label for the corresponding cost options calculated here. Note that one construction class can have multiple costs because it can appear with more than one set of priority zones. Cost options are unique. Even though “option 5” appears in more than one table cell, each instance has the same cost, as is shown in the following tables. The same is true for the baseline case and options 1, 4, and 6. Table 20. Cost options to evaluate for each archetype Exposure level
Priority zones that follow National WUI Guide Section 3.4 None
1A
1A and 1
1A to 2
1A to 3
CC1(FR)(1): Baseline
CC1: Option 2
CC3: Option 5
CC3: Option 5
CC3: Option 6
Moderate
CC1(FR)(1): Baseline
CC1(FR)(2): Option 1
CC2: Option 4
CC3: Option 5
CC3: Option 6
High
CC1(FR)(1): Baseline
CC1(FR)(2): Option 1
CC1: Option 3
CC2: Option 4
CC3: Option 6
Ember-only or low
Table 21 provides estimated total costs to retrofit the moderate-to-high hazard archetype house: $7,000 to $45,000, depending on exposure level and choice to follow priority zone recommendations. Measures that rely on construction class CC1 or CC1(FR) (baseline and options 1, 2, and 3) cost $19,000 to $24,000. Vegetation control in a small-to-moderate yard (options 4 or 5) costs much less: $7,000 to $10,000. Option 6 is much more expensive at $45,000, if the homeowner bears the entire cost of vegetation maintenance over priority zones 1A to 3. See Table 22 for retrofit costs for the low-hazard archetype house: $8,000 to $45,000. Measures that rely on construction class CC1 or CC1(FR) cost $26,000 to $31,000. As with the moderate-to-high hazard house, options 4 and 5 are much less expensive, about $8,000.
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