b ilt ▁was ▁involved ▁in ▁the ▁some ▁design ▁of ▁the ▁house , ▁it ▁was ▁primarily ▁a ▁result ▁of ▁the ▁collaboration ▁of ▁Al va ▁V ander b ilt ▁and ▁the ▁architect . ▁ ▁H unt ▁used ▁a ▁bl ending ▁of ▁late ▁French ▁Goth ic ▁style ▁and ▁Be aux - Ar ts ▁ref in ement ▁for ▁the ▁design ▁of ▁the ▁three - and - a - half - story ▁m ansion . ▁ ▁The ▁elaborate ▁asym met rical ▁fac ade ▁was ▁faced ▁in ▁gray ▁Indiana ▁lim estone , ▁with ▁an ▁irregular ▁roof ▁of ▁blue - gray ▁sl ate ▁trim med ▁with ▁co pper . ▁ ▁The ▁m ason ry ▁firm ▁of ▁Ell in ▁and ▁Kit son ▁executed ▁the ▁extensive ▁exterior ▁and ▁interior ▁stone ▁car ving , ▁reported ly ▁employ ing ▁more ▁than ▁ 4 0 ▁art is ans . ▁ ▁Contempor ary ▁architect ural ▁critics ▁generally ▁gave ▁good ▁reviews ▁of ▁the ▁design , ▁with ▁most ▁not ing ▁that ▁this ▁was ▁not , ▁as ▁had ▁previously ▁been ▁the ▁case ▁with ▁Car p enter ▁Goth ic ▁architecture , ▁the ▁past ing ▁of ▁Goth ic ▁detail ▁onto ▁an ▁essentially ▁American ▁frame ▁building . ▁ ▁Inter iors ▁ ▁The ▁interior ▁was ▁entered ▁from ▁Fif th ▁Avenue ▁via ▁an ▁entrance ▁vest ib ule . ▁ ▁The ▁vest ib ule ▁opened ▁onto ▁a ▁ ▁long ▁grand ▁hall , ▁which ▁could ▁be ▁used ▁to ▁access ▁all ▁of ▁the ▁primary ▁first ▁floor ▁rooms . ▁ ▁The ▁grand ▁hall ▁was ▁faced ▁in ▁Ca en ▁stone , ▁as ▁was ▁much ▁of ▁the ▁interior . ▁