Renovation is both greener and cheaper than new-build

Green transition 2 December 2020 Peter Andreas Norn

The construction industry currently accounts for 30% of the total carbon emission in Denmark. As a response to the political aim of reducing 70% of the country's greenhouse gasses, an analysis has been conducted to investigate national carbon emission and economic impact of renovation and new constructions.

Expert columns
5 min

By Lejla Delalic

A Danish study on climate and economic consequences of construction has revealed that renovating is a more climate friendly and economically sound choice, as opposed to constructing new buildings. This is vital insight to encourage the buildings sector to play its part towards a low-carbon economy.

Renovating homes and buildings is often a highly complex task with unforeseen hurdles. So often, demolition and building something new is easier. But is new-build also wiser? No, says a new study conducted by Ramboll for ‘Renovering på Dagsordenen’, a Danish partnership organisation working to put renovations on the agenda.

As ‘easiness’ is not the key metric for a low-carbon economy, the sector needs to increase the use of renovation as this has a lower carbon impact compared to building new. And what is more, renovations are typically cheaper than building new.  

Four key insights

Using life cycle analyses (LCA) and life cycle cost analyses (LCC), Ramboll experts performed a comprehensive assessment of 16 cases ranging from family homes and terraced houses to tower blocks, non-residential buildings and public buildings. The main findings were:

  • Renovating is better for the environment and the economy
  • Carbon emission in new construction depends on materials used
  • The scope of renovation determines the degree of carbon impact
  • Carbon impact differs relative to a construction’s life cycle

"There is a huge potential to globally reduce carbon emission if relevant stakeholders adapt these insights and rethink the way that we currently work within the sector"

Peter Andreas Norn, Senior Market Manager, Ramboll

Renovating is better for the environment and the economy

But why are renovations more climate-friendly? According to Ramboll senior expert, Peter Andreas Norn, the life-cycle-perspective is a chief instrument for both the environmental and economic logic: 

- The reason for the remarkable difference can be found in the amount of greenhouse gasses that are released during the entire life cycle of the materials - with many more virgin materials going into building new. All the way from the extraction of the materials to the transport, the actual construction and to demolition of the old building. With this in mind, new-build is far more polluting than renovation.

Carbon emission in new constructions depends on materials used

In assessing whether to build new or renovate, it is important to consider which materials are to be used. Some materials cause more carbon emission than others, and when deciding in favour of the climate, wood is a convenient choice.

The report shows that wooden constructions are less polluting compared to conventional building materials, such as steel, concrete and bricks. 

The scope of renovation determines the degree of carbon impact

For older buildings, most carbon emissions are typically related to excessive consumption of heat, water, and electricity, due to inadequate insulation and potential leaks. 

On the other hand, new construction burdens the environment mostly due to the materials used for construction, whilst energy consumption in these cases remains relatively low.

Carbon impact differs relative to a construction’s life cycle

The 50-year life cycle analysis shows that there is a remarkable difference as to when carbon emission occurs in the processes of renovation and new construction. 

For renovation scenarios, carbon emission is relatively high in the first half of the period of observation. Later, the curve evens out.

In comparison, carbon emission from new-build is shown to be notably higher than that of renovation in the first 30 years period of time.

An increased focus on renovations rather than new-build will therefore enable a positive contribution to the work towards the reduction of carbon emission.

Specific actions towards the reduction of carbon emissions

The insights generated from the report provide the industry with guidelines as to how they can contribute to a solution to a central theme on the political agenda – namely the ambition to reduce Denmark’s carbon emission by 70% no later than 2030.

Despite the national focus, the findings have global potential:

- The analysis is based on Danish cases, but it can easily be transferred to other countries as well. There is a huge potential to globally reduce carbon emission if relevant stakeholders adapt these insights and rethink the way that we currently work within the sector, concludes Peter Andreas Norn.

> Download the report here (Danish version)

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