Fire protection and design rules for Hawaiian-style structures

405.1 Fire protection classifications. Fire protection for Indigenous Hawaiʻian architecture structures shall be as required in Table 405.1. Table 405.1 — Fire Protection Requirements Based on Setback Class Setback Requirements Fire Protection Requirements A The structure (or a group of structures) is: 1. Located at least 100 feet from any existing structure on the same or neighboring properties; and 2. Located at least 100 feet from any property line, except as follows: a. If the property line abuts a public way, the 100 feet minimum setback for that property line shall be reduced by the width of the public way, b. If the property line abuts the shoreline, the minimum setback for that property line shall be the shoreline setback, or c. For any hale ku'ai in the agricultural district that is less than 200 square feet, that is completely open on three sides, and that is used as an agricultural products stand and if the property line abuts a public way, the minimum setback for that property line shall be 15 feet. No fire protection is required for the structure. B The structure (or a group of structures) that conforms to applicable zoning setback requirements but does not satisfy Class A setback requirements. Automatic fire sprinkler system shall be installed in accordance with design standards in section 3805.2. An electrical permit is required for fire sprinklers systems.   405.2 Automatic fire sprinklers. The design standards for automatic fire sprinklers for Class B indigenous Hawaiʻian architecture structures shall be in accordance with NFPA 13. Exception: The design standards for automatic fire sprinklers for Class B indigenous Hawaiʻian architecture structures shall be permitted as follows: 1. 18 gallons per minute for a single head at 140 square feet maximum coverage of roof area. 2. 13 gallons per minute for each subsequent head at 140 square feet maximum coverage of roof area per head. 3. The minimum supply pressure at the base of the riser shall not be less than 40 pounds per square inch. 4. The minimum residual pressure at the highest sprinkler shall be not less than 12 pounds per square inch. 5. Sprinkler head spacing shall not exceed 14 feet. 6. Sprinkler heads shall be open type upright, pendent, or sidewall with 1/2-inch or 17/32-inch orifice and have a wax corrosion resistant coating. 7. The total number of sprinklers on a branch shall not exceed 6 heads. 8. The total number of sprinklers shall not exceed the quantity shown in Table 405.2(a). Table 405.2(a) — Total Number of Fire Sprinklers Based on Pipe Size Pipe Sizing Number of Sprinklers 1 inch diameter 2 sprinklers 1 ¼ inch diameter 3 sprinklers 1 ½ inch diameter 5 sprinklers 2 inch diameter 10 sprinklers 2 ½ inch diameter 30 sprinklers 3 inch diameter 60 sprinklers   9. The pipe schedule in Table 405.2(a) shall not apply to hydraulically designed systems. 10. The water density shall not be less than 0.10 gpm per square foot. 11. The source of water may be by domestic water meters, detector check meter, underground well, storage tank, swimming pool, ponds, etc., but must meet the design requirements for adequate pressure and duration. 12. Water supply shall be sufficient to provide 30 minutes duration. 13. If domestic water meters are used as the source of water for the fire sprinklers, without a storage tank and booster pump, the maximum number of sprinklers shall not exceed the number shown in Table 405.2(b). Table 405.2(b) — Total Number of Fire Sprinklers Based on Water Meter Size Size of Water Meter Number of Sprinklers ⅝ inch water meter 1 sprinkler ¾ inch water meter 2 sprinklers 1 inch water meter 3 sprinklers 1 ½ inch water meter 7 sprinklers 2 inch water meter 11 sprinklers 3 inch water meter 27 sprinklers   14. The piping material shall be hard drawn copper with silver solder or brazed fittings, or carbon steel with corrosion-resistant coatings. Plastic pipes shall not be allowed, except for below grade supply pipes. 15. Fire sprinkler system shall be actuated by smoke detectors located at the highest points of the roof and spaced as recommended by the manufacturer. 16. Flow control valves shall be either hydraulically or electrically operated with a manual override switch. 17. Where the width of a roof exceeds the width allowed for one row of sprinklers, two or more rows of sprinklers shall be placed such that the entire roof area is protected. 18. Prevailing wind direction shall be considered in the placement of sprinklers. 19. Deflectors for sprinklers shall be parallel with the roof surface or tilted slightly towards the peak of the roof. 20. Fire sprinklers system shall have a local alarm activated by a smoke detector. 405.3 Certification of water supply. For any hale that requires fire protection pursuant to section 405, the applicant shall provide a certification from a licensed engineer or a licensed C-20 contractor that the water supply for the fire sprinkler system has been tested and is capable of delivering the required fire flow for 30 minutes duration. 405.4 Smoke alarm. Any hale used for sleeping shall have an approved battery-operated smoke alarm installed in the hale. ( Ord. No. 5507 , § 2, 2023) SECTION 406 DESIGN STANDARDS 406.1 General design standards. All types of hale shall be designed and constructed in accordance with the standards set out in this section. 1. The minimum diameter size of all structural members shall be measured at the member's midpoint, except that the minimum diameter size of posts shall be measured at the smaller end. For structure sizes not specifically shown in the tables, the requirements in the next larger width size shall be applicable. 2. The specifications for structural members were estimated based on no wind loads. Hale shall be constructed to allow all thatching materials to separate from the structure prior to adding significant loads. 3. The mix formula for mortar specified in these rules shall be one part portland cement, four parts clean sand, and sufficient fresh water to make the mixture workable. 4. Every hale, except hale noa, shall have at least two sides completely open. 5. Lashing and thatching methods shall comply with illustrations found in "Arts and Crafts of Hawaiʻi" or "The Hawaiʻian Grass House in Bishop Museum" referenced in section 401.2. 406.2 Allowable designs. Hale shall be designed and constructed in accordance with the requirements in sections 406.2.1 through 406.2.4. 406.2.1 Hale Hālāwai. Each end of the Hale Hālāwai may be open or thatched. The ends may also be constructed with a thatched roof hip as an alternate design. Hale Hālāwai shall be designed in accordance with the following schematics and illustrations. Structural components for Hale Hālāwai shall meet the size and spacing requirements in Table 406.2.1(a). Foundations for Hale Hālāwai shall be designed in accordance with Table 406.2.1(b). HALE HĀLĀWAI Open End Style HALE HĀLĀWAI Thatched End Style Framing Schematic Table 406.2.1(a) — Size and Spacing Requirements for Structural Components used in Hale Hālāwai Size W × L × H pou kihi pou kukuna & pou kaha pou hana & pouo manu o'a kuaiole & holo kauhuhu lohelau Maximum post spacing (feet) Maximum rafter spacing (feet) Minimum Diameter (inches) 12′ × 20′ × 7′ 4 3 ½ 4 3 ½ 2 ½ 3 3 5 3 14′ × 24′ × 7′ 4 4 4 ½ 3 ½ 2 ½ 3 3 ½ 5 3 24′ × 30′ × 7′ 5 4 ½ 4 ½ 4 2 ½ 3 3 ½ 5 3 25′ × 50′ × 7′ 5 ½ 5 5 ½ 4 2 ½ 3 3 ½ 5 3 30′ × 60′ × 7′ 6 5 ½ 6 4 ½ 2 ½ 3 4 5 3   KAHUA (PEDESTAL) PĀ PŌHAKU (FOUNDATION WALL) POU KANU (BURIED POST) Table 406.2.1(b) — Foundation Design for Hale Hālāwai Size W × L × H Foundation Type kahua Diameter × Height pā pōhaku Width × Height × Length pou kanu Diameter × Depth 12′ × 20′ × 7′ 3′6″φ × 24″H 2′6″W × 2′8″H × 4′0″L 30″φ × 2′8″D 14′ × 24′ × 7′ 3′8″φ × 24″H 2′6″W × 2′8″H × 4′0″L 30″φ × 2′9″D 24′ × 30′ × 7′ 4′0″φ × 30″H 3′0″W × 3′0″H × 4′0″L 36″φ × 3′0″D 25′ × 50′ × 7′ 4′0″φ × 30″H 3′0″W × 3′0″H × 4′0″L 36″φ × 3′0″D 30′ × 60′ × 7′ 4′0″φ × 30″H 3′0″W × 3′3″H × 4′0″L 36″φ × 3′3″D   406.2.2 Hale Kuʻai. Hale Kuʻai shall be designed in accordance with the following schematics and illustrations. Structural components for Hale Kuʻai shall meet the size and spacing requirements in Table 406.2.2(a). Foundations for Hale Kuʻai shall be designed in accordance with Table 406.2.2(b). HALE KUʻAI SHED STYLE HALE KUʻAI GABLE STYLE FRAMING SCHEMATIC 1 FRAMING SCHEMATIC 2 Table 406.2.2(a) — Size and Spacing Requirements for Structural Components used in Hale Kuʻai Size (W × L × H) pou kihi a pou kaha a pou hana b pouo manu b o'a kuaiole & holo kauhuhu lohelau Maximum rafter spacing (feet) Minimum Diameter (inches) 5′ × 10′ × 5′ 4 3 3 4 3 2 3 2 4 9′ × 12′ × 5′ 4 3 3 4 3 2 3 ½ 2 4 12′ × 16′ × 5′ 4 ½ 3 ½ 4 4 3 ½ 2 4 2 ½ 4 14′ × 20′ × 5′ 4 ½ 3 ½ 4 4 3 ½ 2 ½ 4 ½ 2 ½ 4   a The maximum post spacing for pou kihi and pou kaha is five feet. b The maximum post spacing for pou hana and pouomanu is twelve feet.   KAHUA (PEDESTAL) POU KANU (BURIED POST) Table 406.2.2(b) — Foundation Design for Hale Kuʻai Size (W × L × H) Foundation Type kahua Diameter × Height pā pōhaku Width × Height × Length pou kanu Diameter × Depth 5′ × 10′ × 5′ 3′0″φ × 24″H 2′6″W × 2′0″H ×4′0″L 30″φ × 2′6″D 9′ × 12′ × 5′ 3′4″φ × 24″H 2′6″W × 2′0″H × 4′0″L 30″φ × 2′6″D 12′ × 16′ × 5′ 3′6″φ × 24″H 2′6″W × 2′8″H × 4′0″L 30″φ × 2′8″D 14′ × 20′ × 5′ 3′8″φ × 24″H 2′6″W × 2′8″H × 4′0″L 30″φ × 2′9″D   406.2.3 Hale Noa. Hale Noa shall have at least two openings. One opening shall be at least 3 feet wide and 5 feet high, and the other opening shall be at least 2 feet wide and 3 feet high. Hale Noa shall be designed in accordance with the following schematics and illustrations. Structural components for Hale Noa shall meet the size and spacing requirements in Table 406.2.3(a). Foundations for Hale Noa shall be designed in accordance with Figure 406.2.3(b). HALE NOA FRAMING SCHEMATIC Table 406.2.3(a) — Size and Spacing Requirements for Structural Components used in Hale Noa Size (W × L × H) pou kihi pou kukuna & pou kaha pou hana pouo manu o'a kuaʻiole & holo kauhuhu lohelau Maximum post spacing (feet) Maximum rafter spacing (feet) Minimum Diameter (inches) 9′ × 12′ × 7′ 3 ½ 3 4 3 3 2 ½ 3 ½ 2 ½ 6 4 12′ × 20′ × 7′ 4 4 ½ 4 3 3 ½ 2 ½ 3 ½ 2 ½ 6 4 4′ × 24′ × 7′ 5 ½ 4 ½ 4 3 3 ½ 2 ½ 3 ½ 3 6 4   Figure 406.2.3(b) 406.2.4 Hale Waʻa. Hale Waʻa shall be designed in accordance with the following schematics and illustrations. Structural components for Hale Waʻa shall meet the size and spacing requirements in Table 406.2.4(a). Foundations for Hale Waʻa shall be designed in accordance with Figure 406.2.4(b). HALE WAʻA FRAMING SCHEMATIC Table 406.2.4(a) - Size and Spacing Requirements for Structural Components used in Hale Waʻa Size (W × L) oʻa kuaʻiole & holo kauhuhu Spacing between Rafters Minimum ridge Height (H) 20′ × 60′ 4″ 3″ 4″ 4′ to 5′ 22½′ 25′ × 60′ 5″ 3″ 4″ 4′ to 5′ 27½′ 30′ × 60′ 5½″ 3″ 4″ 4′ to 5′ 27½′   Figure 406.2.4(b) ( Ord. No. 5507 , § 2, 2023) _____