Reduce Emissions: stop demolishing heritage buildings – adapt, retrofit and reuse them instead

Figure 4 of Ontario’s Climate Change Discussion Paper shows that the waste, transportation and building sectors  all showed increased emissions.  To stop this, ACO North Waterloo Region believes that Ontario’s climate change strategy should include measures which recognize the very positive environmental impact of conserving and retrofitting heritage buildings.

We strongly advocate that measures be taken to stop demolishing heritage buildings — adapt, retrofit and reuse them instead.

 There is strong evidence to show this will reduce emissions.

chart showing number of years it takes for a new energy efficient building to overcome the negative environmental impacts of construction and demolition of the heritage building it replaced

A 2012 study by the Preservation Green Lab of Washington’s National Trust for Historic Preservation showed that if old (heritage) buildings were demolished and replaced with new buildings, even highly energy efficient buildings, it would take between 10 and 80 years for the environmental assaults suffered in the new construction to be overcome by the higher operating efficiency of the new  buildings.[1]

The study looked at seven different building types, including commercial offices, single and multi-family homes, urban village mixed use, schools, and warehouse conversions.  It did Life Cycle Analyses of the emissions and other environmental impacts of retrofitting an existing heritage building  vs. building a new building of the same dimensions.  It did this in four climate areas: Chicago, Portland, Atlanta and Phoenix, a total of 28 different comparative studies.

Considering Ontario’s 2020 target date, and leaving aside conversions of warehouses to luxury living spaces, there was not a single case where it’s better for our climate and environment to replace old buildings with new, highly energy-efficient ones of a similar size.

The negative climate change effects come from the impacts of demolition (e.g. energy to destroy and truck to landfills) and from the manufacture and transportation of replacement raw materials and building components.

So, we need measures which discourage the demolition of heritage buildings:

  1. require Life Cycle Assessments to be part of all new construction proposals;
  2. require proof that demolition is necessary (reversing the current assumption that older and vacant buildings should be destroyed, where the onus is on heritage advocates to prove such buildings should be kept);
  3. prohibit property tax reduction for vacant premises;
  4. introduce a special Carbon Demolition Tax: a tipping fee at landfills that puts a high surcharge on waste materials from demolitions where there is no plan to replace the destroyed building with a structure that is demonstrably more energy efficient (this might slow down the demo of serviceable structures where the lot is then left empty);
  5. require recycling of building materials – bricks, timber, glass.

“The greenest building is the one already built”

 – Submitted March 23 to Ontario Climate Change Strategy Consultation

 If you like our submission, please vote it up.

[1] Preservation Green Lab.  The Greenest Building: Quantifying the Environmental Value of Building Reuse. Washington, D.C.: National Trust for Historic Preservation, 2012.  Available from Internet: