Could we 'recycle' more old buildings, instead of demolishing them?

A large part of this increase will involve the demolition of existing buildings to be replaced with new larger structures, most often involving extensive use of concrete.

Cement and concrete production create an estimated seven per cent of the world’s CO2 emissions and is the largest contributor to 'embodied carbon' in the built environment.

Embodied carbon is the amount of carbon produced in the process of manufacturing materials, transport and construction of a building as well as that produced in maintaining the building over its life span and eventually demolishing it, transporting the waste, and recycling it.

The embodied carbon of existing buildings can easily be quantified. Many architects and developers do quantify the operational carbon footprint of a new building. However, they rarely consider the embodied carbon of an existing building in proposing its demolition to be replaced by something new.

Some forward-thinking developers, including City of York Council and partner Caddick Construction (for phase 1) in their planning for the construction of 400 zero-carbon ‘Passivhaus’ homes in the city, have started to consider the embodied carbon in the design process of these new buildings.

Existing buildings, unless protected by some national or local designation, are often seen as too expensive to convert and therefore the easy option is to demolish and rebuild.

Many existing buildings do not fit with a modern aesthetic or are not easily converted to new uses. However, their removal does nothing to help with aspirations to be carbon neutral in the future.

The removal of existing buildings can also have a negative impact on people’s health and well-being. People build up strong associations with places that in many cases help form part of their identity.

Demolishing buildings that are socially significant, having been part of many thousands of people’s lives, has been shown to demolish part of people’s own identity.

Buildings and places often form strong associations with people’s lives - of course not always positive.

They are often linked to major events or have been a constant throughout part of our life - churches, workplaces, areas where we played, places we spent our leisure time or that offered respite.

The embodied experience of these buildings is very difficult to quantify but is perhaps just as important as assessing the embodied carbon of a building.

York’s economy in the 2020s is built on the city's appeal to people as a place to visit, live and work - its look and feel. Tourism is ever more focussing on an experience economy in the city.

As greater numbers of buildings are demolished to make way for larger new modern buildings there is a risk that the city will lose some of its layers of time appeal and buildings that people return to see, and feel may no longer exist. Once a building has gone from sight it is often diminished in memory.

Not all existing buildings are worth retention and new buildings can, of course, greatly improve a place. Many existing buildings were poorly built with short life expectancies whose materials and design even contributed to poor health and well-being. The removal of their negative impact on people can be a good thing. But how are we to know?

How do we quantify the embodied experience of buildings? As part of any proposal to demolish a building should there be additional elements of the process that require greater publicity of the loss of the building to encourage deeper engagement with people to provide opportunities for them to express and record their experiences of that place?

Should evidence of embodied experience be given weight in any decision making relating to demolition? Where does this information reside once a decision has been made?

York’s Local Heritage List, on which York Civic Trust is working closely with the City of York Council, communities, individuals and organisations to enhance, is one tool for highlighting those buildings that are important to local people.

But it is only a limited tool. Is it time to think more creatively about how we realize and record people’s experiences of buildings to ensure that we are not losing important elements of the social landscape of York for the future?

Andrew Morrison is chief executive of York Civic Trust