The gap is substantial: major renovation typically emits 2 to 4 times less than new construction with an equivalent floor area. Demolition and waste treatment emissions are avoided, the existing structure is retained, having already amortised its construction emissions, and only renovation materials generate emissions (insulation, windows and doors, systems). Developers rarely make this calculation, but it is now incorporated into some ESG decisions.
Read the source article: A new building's carbon footprint: the RE2020 figures