The point is that contemporary inserts into historical spaces are not always a bad thing. Contrast this with Raphael Moneo's addition to the Atocha Station- another building evoking the eighties and some of the horrors that Botta and Bofill were up to at the time. The interior spaces are interesting specially the train platforms themselves, which are a delight. But I am not sure how the drum-like central circulation space and the cuboid clock tower sit with the fabulousl19th century glass and iron station.
On the subject of retrofit, the last word surely goes to the lift installed in our tiny B&B- the Hostal Luz on the Arenal. Fitted in (the perhaps two feet three inches wide) stairwell of an older four floor building, the elevator is exquisite in its modernity- with all the fittings- the stainless steel and glass that made the Reina Sophia's what it is. Wide enough to accommodate me, but not me with a rucksack, making me feel like a mujera in a tube top, traveling in it made up in style, elegance and convenience whatever it lacked in volume.