Lower Than South-East Florida, and Still Serious

A homeowner sold an HVHZ product for a non-HVHZ address may be over-specified and overpaying. Another, on an exposed waterfront lot at height, may be under-specified because somebody used a general figure rather than calculating. Both come from quoting a product before calculating the requirement.

The under-specification risk is the more serious one and gets less attention. A homeowner focused on avoiding an unnecessary HVHZ premium can end up with products that do not meet the pressures on their most exposed openings, which is a worse outcome than overpaying.

Exposure category accounts for what surrounds a building. A house facing open water or open ground with nothing upwind is in a more severe exposure than one of the same size surrounded by mature trees and other houses, and the calculated pressures differ accordingly.

Height matters too, and so does the position of each opening on the elevation. This is why a per-opening schedule is the only meaningful basis for specification and why a single figure quoted for a house is not information.

1. 01Calculate design pressures per opening before quoting product.
2. 02Use the actual location, exposure and height.
3. 03Provide the pressures in writing.
4. 04Select products approved to meet them.

Corner zones need higher-rated units than the middle of a wall. It is a standard part of the calculation, it is routinely ignored in quotes, and it is why some houses lose exactly the corner windows first.

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