Lower cost/embodied-energy alternative to triple glazing; still a large step above single glazing.
Cost
Medium
Upkeep
None
Skill to build
Intermediate
Lifespan
20-35 years, same sealed-unit failure mode as triple glazing
Embodied carbon
Medium
Space / material use
Low
Output timing
None
Skill to repair
Intermediate
Regulation (FR example)
Changing the external appearance of an existing building normally requires a prior declaration (declaration prealable) at the mairie; stricter rules and an architect consultation apply within a protected or heritage perimeter.
Note: Cost, carbon and footprint are rated against the other options for this same need, not in absolute terms.
Inputs
none
Outputs
none
Sources
Glazing industry lifespan sources (Glass & Glazing Federation guidance via Everest/Gowercroft consumer glazing sites)
What this page does not tell you
No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.