"International research shows that the building industry produces nearly 40 percent of all greenhouse gases. Most new buildings erected in the present are built for a 50-year lifespan, meaning they will not survive long enough to repay the amount they cost in carbon to construct. Conversely, preserving older buildings contributes to climate change solutions by storing energy (or embodied energy)."
- #BenSchrader, Wellington historian, 2021
Older buildings have very low energy efficiency so they result in huge CO2 emissions during their operations. High energy efficiency standards would increase the cost of investment, so it would make more sense to keep them for longer to get better ROI.
@kravietz
> Older buildings have very low energy efficiency
... until you retrofit insulation etc to the degree that's possible. Ben's point is that spending a fraction of the money required for a new building is often enough to cancel out any advantages gained through new builds, even when they're optimized for greater energy efficiency, which is not always the case.
> you retrofit insulation
Been there, doesn't work 😉 Old buildings have hundreds of thermal bridges where energy escapes.
On the other hand, the improvements in this field are largely asymptotic - if you got your house built up to 15 kWh/m2 standard ("passive house") you don't really need to move any further for the next 100 years.
An average UK house has ~100 kWh/m2 usage there's certainly massive room for improvement.
No black & white answers here, need to look case per case.
@kravietz
> No black & white answers here, need to look case per case.
Agreed and I think this is exactly Ben's point. Challenging the idea that a new build is always the best solution and retrofitting is never worthwhile.