Temporary Buildings/Cofferdam

[Max4067]

Dear eTool,

I’m curious as to how temporary buildings or structures fit within the LCA scope/boundary. I understand formwork and the like is generally included within the templates. But, what about other temporary structures such as cofferdams? Projects that are constructed on or near water will generally have a temporary cofferdam to keep water away from the site. When construction works are completed, the cofferdam structure (which can be made soil, reinforced earth, timber bracing) is removed.

My question is whether the cofferdam is to be included in the LCA?

[Fei Ngeow]

Hi Max,

Thank you for your question! In terms of how they fit within the LCA scope, there are two categories for temporary structures according to the RICS new rules of measurement under ‘Facilitating Works’. These are ‘Temporary support to adjacent structures’ and ‘Temporary diversion works’. I believe cofferdams should fit pretty well under the latter sub-category. I hope that answers your question!

[Max4067]

Thanks Fei for the response; very helpful.

[Max4067]

Fei,

further to this. Say, for example, if the temporary structures were excluded from the scope of the project’s applicable rating tool (Green Star or the like) and specifically to the LCA credits, would the temporary structure not be required to be modelled in the LCA?

[Fei Ngeow]

Hi Max,

As long as the omissions comply with LCA standards’ cut-off rules then it should be fine. What are the cofferdams built from and what do the material estimates look like?

With regards to whether it’s ‘required’ or not, we always conduct our reviews and strongly encourage our users to model their LCA studies according to EN 15978 standards (i.e. as per cut-off rules) rather than to rating schemes.