1. Feem ntau cov windowsills qis yog li 0.5 meters los ntawm hauv av. Ntxiv 0.4-meter railing lossis laj kab ze rau ntawm phab ntsa sab hauv yuav ua tau raws li cov qauv kev nyab xeeb uas xav tau. Yog hais tias lub windowsill loj dhau, xws li lub qhov rais bay, cov menyuam yaus feem ntau sawv ntawm nws saib, thiab cov neeg siv yuav tsum sawv ntawm windowsill qhib lub qhov rais. Nyob rau hauv rooj plaub no, railing nws tus kheej yuav tsum yog tsawg kawg yog 0.9 meters siab. Qhov siab ntawm lub railing yuav tsum tsis txhob tsawg tshaj li 1.05 meters, thiab rau nruab nrab - nce thiab siab-sawv vaj tse, qhov siab qhov siab yuav tsum tsis txhob tsawg tshaj li 1.1 meters.
2. Thaum qhov siab tshaj hauv av yog tsawg dua 24 meters, qhov siab ntawm railing yuav tsum tsis pub tsawg tshaj 1.05 meters. Thaum qhov siab tshaj hauv av yog 24 meters lossis ntau dua (nrog rau nruab nrab-nce thiab siab-nce qhov nyob), qhov siab ntawm qhov rooj yuav tsum tsis pub tsawg dua 1.10 meters. Qhov siab ntawm lub railing yuav tsum tau xam vertically ntawm hauv pem teb los yog lub ru tsev nto mus rau sab saum toj ntawm lub tes tuav. Yog hais tias muaj ib tug foothold nyob rau hauv qab nrog ib tug dav ntau dua los yog sib npaug zos rau 0.22 meters thiab ib qhov siab tsawg dua los yog sib npaug zos rau 0.45 meters, qhov siab yuav tsum tau xam los ntawm sab saum toj ntawm foothold.
3. Rau cov plag tsev siab dua, qhov siab yuav tsum tsis pub tshaj 1.2 meters. Lub railing qhov siab yog xam vertically ntawm hauv pem teb qhov twg nws yog ntsia rau ntawm lub sam thiaj mus rau sab saum toj ntawm lub tes tuav. Yog hais tias muaj ib tug foothold nyob rau hauv qab ntawm lub railing nrog ib qhov siab tsawg tshaj li 0.5 meters, qhov siab yuav tsum tau xam los ntawm sab saum toj ntawm lub foothold. Cov kev cai tshwj xeeb feem ntau tau teev tseg hauv cov duab kos duab, thiab qhov siab yam tsawg kawg nkaus yog 1.0 meter.
