Ngakho-ke, abanye abadwebi bezakhiwo, njengefemu yezakhiwo i-Waugh Thistleton, bafuna ukubuyela okhunini njengempahla yokwakha eyinhloko. Izinkuni ezivela emahlathini zimunca ikhabhoni, zingayikhiphi: njengoba izihlahla zikhula, zimunca i-CO2 emkhathini. Njengomthetho, i-cubic meter yezinkuni iqukethe cishe ithani le-CO2 (kuye ngokuthi uhlobo lwezinkuni), elilingana namalitha angu-350 kaphethiloli. Akukhona nje kuphela ukuthi ukhuni lususa i-CO2 eningi emkhathini kunokuba lwenza ngesikhathi sokukhiqiza, luphinde luthathe indawo yezinto ezithatha ikhabhoni njengokhonkolo noma insimbi, okuphinda kabili umnikelo walo ekwehliseni amazinga e-CO2.
“Ngenxa yokuthi isakhiwo samapulangwe sinesisindo esingaba ngu-20% sesakhiwo sikakhonkolo, amandla adonsela phansi ancipha kakhulu,” kuphawula umklami u-Andrew Waugh. “Lokhu kusho ukuthi sidinga isisekelo esincane, asidingi ukhonkolo omningi phansi. Sinomgogodla wokhuni, izindonga zokhuni namapulangwe aphansi okhuni, ngakho sigcina inani lensimbi lincane.” Insimbi ijwayele ukusetshenziselwa ukwakha izisekelo zangaphakathi kanye nokuqinisa ukhonkolo ezakhiweni eziningi zesimanje ezinkulu. Nokho, mancane amaphrofayili ensimbi kulesi sakhiwo sokhuni,” kusho uWaugh.
Phakathi kuka-15% no-28% wezindlu ezintsha ezakhiwe e-UK zisebenzisa ukwakhiwa kohlaka lwamapulangwe unyaka ngamunye, okumunca amathani angaphezu kwesigidi e-CO2 ngonyaka. Umbiko uphethe ngokuthi ukwanda kokusetshenziswa kwezinkuni ekwakheni kungaphinda kathathu lelo nani. “Kungenzeka ukonga ngezinga elifanayo emkhakheni wezohwebo nezimboni ngokusebenzisa izinhlelo ezintsha ezithuthukisiwe njengokhuni olunalayini oluphambanayo.”
Ugodo olunalayini oluphambanayo, noma i-CLT, luyisisekelo sesiza sokwakha esiboniswa ngu-Andrew Waugh e-East London. Ngenxa yokuthi ibizwa ngokuthi “ukhuni olunjiniyela,” silindele ukubona okuthile okufana ne-chipboard noma i-plywood. Kodwa i-CLT ibukeka njengamapulangwe ajwayelekile angama-3 m ubude no-2,5 cm ubukhulu. Iphuzu liwukuthi amabhodi aba namandla ngokunamathela ndawonye amathathu ezingxenyeni ze-perpendicular. Lokhu kusho ukuthi amabhodi e-CLT "awagobi futhi abe namandla aphelele ezinhlangothini ezimbili."
Ezinye izinkuni zobuchwepheshe ezifana ne-plywood ne-MDF ziqukethe cishe u-10% wokunamathela, ngokuvamile i-urea formaldehyde, engakhulula amakhemikhali ayingozi ngesikhathi sokucubungula noma ukushiswa. I-CLT, nokho, ine-adhesive engaphansi kwe-1%. Amabhodi ahlanganiswe ndawonye ngaphansi kwethonya lokushisa nokucindezela, ngakho inani elincane leglue lanele ukuhlanganisa usebenzisa umswakama wezinkuni.
Nakuba i-CLT yasungulwa e-Austria, ifemu yezokwakha ezinze eLondon i-Waugh Thistleton yaba ngeyokuqala ukwakha isakhiwo esinezitezi esasetshenziswa u-Waugh Thistleton. I-Murray Grove, ibhilidi elivamile elinezitezi eziyisishiyagalolunye elinezitezi ezimpunga, libangele "ukwethuka nokwethuka e-Austria" lapho liqedwa ngo-2009, kusho uWu. I-CLT ngaphambili yayisetshenziselwa kuphela "izindlu ezinhle nezilula ezinezitezi ezimbili", kuyilapho ukhonkolo nensimbi kwakusetshenziselwa izakhiwo ezinde. Kodwa ku-Murray Grove, sonke isakhiwo siyi-CLT, enazo zonke izindonga, ama-slabs aphansi kanye nama-elevator shafts.
Lo msebenzi ugqugquzele abaklami bezakhiwo abangamakhulu ukuthi bakhe izakhiwo ezinde nge-CLT, kusukela eBrock Commons engamamitha angu-55 eVancouver, eCanada kuya eHoHo Tower enezitezi ezingu-24 engamamitha angu-84 esakhiwayo eVienna.
Muva nje, kube nezingcingo zokutshala izihlahla ngezinga elikhulu ukuze kuncishiswe i-CO2 nokuvimbela ukushintsha kwesimo sezulu. Kuthatha iminyaka engaba ngu-80 ukuba izihlahla zikaphayini emahlathini, njengesihlahla sonwele saseYurophu, zivuthwe. Izihlahla ziyizinki zekhabhoni phakathi neminyaka yazo yokukhula, kodwa lapho sezivuthiwe zikhipha ikhabhoni eningi ngangokunokwenzeka. Ngokwesibonelo, kusukela ngo-2001, amahlathi aseCanada empeleni abekhipha ikhabhoni eningi kunaleyo ayimuncayo, ngenxa yokuthi izihlahla ezivuthiwe ziyekile ukugawulwa.
Indlela yokuphuma ukugawulwa kwezihlahla emahlathini nokuvuselelwa kwazo. Imisebenzi yamahlathi ijwayele ukutshala izihlahla ezimbili kuya kwezintathu kuzo zonke izihlahla ezigawuliwe, okusho ukuthi uma kunesidingo esikhulu sokhuni, kuzovela izihlahla ezincane kakhulu.
Izakhiwo ezisebenzisa izinto ezenziwe ngokhuni nazo zivame ukushesha futhi zibe lula ukwakha, ukunciphisa abasebenzi, amafutha okuthutha kanye nezindleko zamandla wendawo. U-Alison Uring, umqondisi wenkampani yengqalasizinda i-Aecom, wenza isibonelo sesakhiwo sokuhlala i-CLT esingamayunithi angu-200 esathatha amasonto angu-16 nje kuphela ukwakhiwa, obekuzothatha okungenani amasonto angu-26 ukuba sakhiwe ngokwesiko ngohlaka lukakhonkolo. Ngokufanayo, uWu uthi isakhiwo esisha se-CLT esingamamitha-skwele angu-16 asebenze kuso “besingadinga ukudiliva amaloli kasimende angaba ngu-000 ukuze kusekelwe isisekelo kuphela.” Kwabathatha kuphela ukuthunyelwa okungu-1 ukuletha zonke izinto ze-CLT.