{"id":"curtain-wall","version":"0.1.0","classification":{"uniformat":"B2020"},"names":["Curtain wall glazing"],"aliases":["curtain wall","IGU"],"service_life":{"median_years":40,"range_years":[40,40],"range_basis":"source_spread"},"pm_tasks":[],"basis":[{"type":"public_document","life_type":"planning","title":"CNA e-Tool Estimated Useful Life Table","by":"U.S. Department of Housing and Urban Development","url":"https://www.hud.gov/sites/documents/eul_for_cna_e_tool.pdf","page":7,"code":"HUD CNA 3.3.3.1.7","label":"Metal/Glass Curtain Wall","years":40,"note":"Same life for family and elderly properties. US multifamily housing."}],"confidence":{"grade":"C","sample_size":null},"open_questions":["Only one source so far: HUD planning lives for US multifamily housing. Canadian and observed sources are needed.","No preventive maintenance tasks are sourced yet."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-21","canonical_url":"https://unfinished.one/c/curtain-wall","versioned_url":"https://unfinished.one/c/curtain-wall/v/0.1.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Curtain wall glazing, v0.1.0. https://unfinished.one/c/curtain-wall/v/0.1.0"}