Every now and then I come across small buildings that are an assemblage of reclaimed windows and doors fitted together like a game of Tetris. Many are like this glass house in, fittingly, Christiania, Denmark:

[Photo: seier+seier]

Or this Cabin in West Virginia by Nick Olson and Lilah Horwitz:

As much as I like the appearance of these sort of makeshift constructions, I figure any sustainability points gained in reusing old windows and doors are offset by the heat gain and loss of what I imagine to be single panes of glass. Hence these elements are better suited for interiors, as in Studio Boot in 's-Hertogenbosch, Netherlands, by Studio Boot + Hilberink Bosch Architecten:

Or temporary installations, as in Bow-House in Heerlen, Netherlands, by Malka Architecture:
But easily the most ambitious project I've come across with the architectural element of reclaimed windows and doors is the Collage House in Mumbai, India, by S+PS Architects:

[Photo: Sebastian Zachariah]

Much like Wang Shu and Lu Wenyu appropriate tiles from demolished buildings for their campus structures in China, the folks at S+PS have incorporated old windows and doors from demolished buildings in Mumbai. According to Domus, where I spotted this project, the incorporation of historical elements doesn't end at the walls at the front of the house: "Hundred-year-old columns from a dismantled house bring back memories ... One finds use of recycled materials like old textile blocks, flooring mad...