The number of steps built down into the interior means that it is unsuitable for the infirm or those with heart problems.
( ( ( The number ) ( of ( steps ( ( built down ) ( into ( the interior ) ) ) ) ) ) ( ( means ( that ( it ( ( is ( unsuitable ( for ( ( ( the infirm ) or ) those ) ) ) ) ( with ( heart problems ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NP (NNS steps)) (VP (VBN built) (PRT (RP down)) (PP (IN into) (NP (DT the) (NN interior))))))) (VP (VBZ means) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ is) (ADJP (JJ unsuitable) (PP (IN for) (NP (NP (DT the) (NN infirm)) (CC or) (NP (DT those))))) (PP (IN with) (NP (NN heart) (NNS problems))))))) (. .)))
The interior is well suited for those with cardiac issues.
( ( The interior ) ( ( ( is well ) ( suited ( for ( those ( with ( cardiac issues ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN interior)) (VP (VBZ is) (ADVP (RB well)) (VP (VBN suited) (PP (IN for) (NP (NP (DT those)) (PP (IN with) (NP (JJ cardiac) (NNS issues))))))) (. .)))