▁The ▁process ▁starts ▁with ▁a ▁cost ▁estimate ▁from ▁blue print s ▁and ▁material ▁take ▁off s . ▁ ▁The ▁tender ▁is ▁treated ▁as ▁an ▁offer ▁to ▁do ▁the ▁work ▁for ▁a ▁certain ▁amount ▁of ▁money ▁( f irm ▁price ), ▁or ▁a ▁certain ▁amount ▁of ▁profit ▁( cost ▁re imb urs ement ▁or ▁cost ▁plus ). ▁The ▁tender , ▁which ▁is ▁submitted ▁by ▁the ▁compet ing ▁fir ms , ▁is ▁generally ▁based ▁on ▁a ▁bill ▁of ▁quantities , ▁a ▁bill ▁of ▁approximate ▁quantities ▁or ▁other ▁specific ations ▁which ▁enable ▁the ▁tend ers ▁to ▁att ain ▁higher ▁levels ▁of ▁accuracy , ▁the ▁statement ▁of ▁work . ▁ ▁For ▁instance , ▁a ▁bill ▁of ▁quantities ▁is ▁a ▁list ▁of ▁all ▁the ▁materials ▁( and ▁other ▁work ▁such ▁as ▁amount ▁of ▁exc av ation ) ▁of ▁a ▁project ▁which ▁have ▁sufficient ▁detail ▁to ▁obtain ▁a ▁real istic ▁cost , ▁or ▁rate ▁per ▁described ▁item ▁of ▁work / material . ▁The ▁tend ers ▁should ▁not ▁only ▁show ▁the ▁unit ▁cost ▁per ▁material / work , ▁but ▁should ▁also ▁if ▁possible , ▁break ▁it ▁down ▁to ▁labour , ▁plant ▁and ▁material ▁costs . ▁In ▁this ▁way ▁the ▁individual ▁who ▁is ▁selecting ▁the ▁tender ▁will ▁be ▁quite ▁confident ▁that ▁the ▁tender ▁is ▁feas ible . ▁B ids ▁are ▁not ▁only ▁chosen ▁on ▁cost ▁alone . ▁Sometimes ▁contract ors ▁submit ▁lower ▁tend ers ▁to ▁win ▁the ▁contract ▁and ▁win ▁the ▁work . ▁Either ▁the ▁costs ▁that ▁the ▁contract or ▁inc urs ▁are ▁greater ▁than ▁the ▁price ▁he ▁is ▁charg ing