To refurbish or rebuild? That is the question. Is it more environmentally cheaper to knock down your old house and rebuild it so that it’s squeaky green? Or is it better to convert what you already have?
Many house builders claim that new homes are four times more efficient than older houses. Sure there’s the initial surplus of CO2 to get it built, but the lower emissions will make up for that over the years. That is not so.
The Building and Social Housing Foundation (BSHF) and The Empty Homes Agency of England did a study that compared the CO2 given off in building new homes and creating new homes through refurbishing old properties. The key findings are:
Carbon dioxide (CO2) emissions from new homes fall into two distinct sources: “embodied” CO2 given off during the house building process, and “operational” CO2 given off from normal energy use in the house once it is occupied.
Reusing empty homes could make an initial saving of 35 tons of carbon dioxide (CO2) per property by removing the need for the energy locked into new building materials and construction. Refurbished old homes have lower embodied CO2 and therefore a distinct head start over new homes.
Well-insulated new homes eventually make up for their high embodied energy costs through lower operational CO2 but it takes several decades. This means there almost no difference in the average emissions of new compared with refurbished housing for about 50 years.
Fifty years was not intended to represent the expected lifespan of the house but to represent the likely period before a major refurbishment might be expected. This would provide the next opportunity after initial development in which the environmental performance of the house could be reconsidered and changed.
So if there is no structural damage or need to rebuild, consider refurbishing your house until the next 50 years is up. It’ll save you money and a large CO2 footprint.
