Overview
State-of-the-art curtain wall systems are based on unitized technology. Unitized curtain wall is shop-fabricated, shop-glazed, and installed as individual frames or ‘units’. Frames are normally one lite wide and one storey high, but double-width and double-height frames are not uncommon. The ‘added-value proposal’ behind unitization centers around performing all possible labor in the shop (not on site), because:
  - Unitized installation allows the Builder to close in the building quickly, normally steps behind the concrete pours, getting Inside Trades to work, and hastening turnover and commercialization of the building
  - Unitized fabrication enhances quality control (and minimizes defects in workmanship) by performing all possible work in factory-controlled conditions. Critical workmanship includes application of joint seals, priming and curing of structural silicones, installation of gaskets, and related quality inspection
    - Unitized installation minimizes field labor costs by transferring labor operations into the shop wherever possible. Fully-unitized systems include shop-installation of all in-fills (glazing, spandrel, panels, stone, etc). More sophisticated systems even have the glazing caps shop-installed, so Trades do not have to work outside of the building envelope on the main portions of the curtain wall.