▁subject ▁to ▁a ▁cross - community ▁vote , ▁either ▁by ▁standing ▁orders ▁or ▁by ▁a ▁pet ition ▁of ▁concern , ▁require ▁support ▁from ▁both ▁a ▁majority ▁of ▁union ists ▁and ▁a ▁majority ▁of ▁national ists . ▁ ▁The ▁Northern ▁Ireland ▁Executive ▁is ▁joint ly ▁led ▁by ▁a ▁First ▁Minister ▁and ▁deput y ▁First ▁Minister ▁who ▁are ▁nominated ▁by ▁the ▁largest ▁parties ▁of ▁each ▁of ▁the ▁two ▁design ations . ▁In ▁ 2 0 1 6 , ▁these ▁parties ▁were ▁the ▁Democratic ▁Union ist ▁Party ▁and ▁S inn ▁F é in . ▁Because ▁the ▁Office ▁of ▁First ▁Minister ▁and ▁deput y ▁First ▁Minister ▁is ▁a ▁joint ▁one ▁under ▁Northern ▁Irish ▁law , ▁the ▁res ignation ▁of ▁either ▁vac ates ▁the ▁whole ▁office . ▁If ▁the ▁office ▁cannot ▁be ▁filled ▁after ▁a ▁seven - day ▁period , ▁the ▁entire ▁assembly ▁is ▁dissol ved ▁and ▁a ▁new ▁assembly ▁election ▁must ▁be ▁called . ▁ ▁History ▁ ▁The ▁R HI ▁scheme ▁in ▁Northern ▁Ireland ▁was ▁managed ▁and ▁set ▁up ▁by ▁the ▁then ▁Department ▁of ▁Enter prise , ▁Trade ▁and ▁In vest ment ▁( DE TI ) ▁in ▁ 2 0 1 2 ▁and ▁was ▁over seen ▁by ▁Ar l ene ▁F oster , ▁the ▁D ET I ▁Minister ▁at ▁the ▁time . ▁The ▁intention ▁of ▁the ▁scheme ▁was ▁for ▁business es ▁and ▁non - dom estic ▁properties ▁to ▁begin ▁using ▁renew able ▁he ating ▁sources ▁such ▁as ▁wood ▁pel lets ▁by ▁offering ▁them ▁gener ous ▁subs id ies . ▁ ▁In ▁the ▁Northern ▁Ireland ▁Program me ▁for