Complex sentence: Apart from the house no part of this scheme was built and the two pre-existing red-brick wings (themselves perhaps owing something to Christopher Wren) remained, although the western (stable) wing was later demolished after the new stables were built.
Split into simpler sentences: Apart from the house no part of this scheme was built as the two pre-existing red-brick wings (themselves perhaps owing something to Christopher Wren). The western (stable) wing was later demolished after the new stables were built.