The 1:5:200 ratio

Whilst preparing a presentation on the benefits of PPT and how it extends beyond construction I sought out a diagram for the 1:5:200 ratio. This is often shown in a whole life cycle management diagram usually shown as a growing series of bubbles.
If the initial construction costs of a building is 1, then its maintenance and operating costs over the years if 5 and the business operating costs (salary of people working in that building) is 200.

However when looking into this I came across the following paper which raised doubt on the accuracy of this ratio.
Exposing the Myth
I am still looking to see if there has been any response since this publication as the diagram is still “in circulation”. It does still do the job of focusing the mind on downstream aspects of building/construction whilst putting PPT into a much more far reaching envelope of influence and potential.

Further reference: (the font of all conjecture)


About Shaun Farrell

I have been involved in the construction sector since 1986 and over the years I have seen things change dramatically. Much of the change has been directly as a result of technology. This blog will be about the key combinations of People, Process and Technology. Any views expressed here are strictly my own.
This entry was posted in Brain Dump, People, Process, Tools. Bookmark the permalink.

One Response to The 1:5:200 ratio

  1. Mac says:


    I’d be interested to learn if you made any headway with this one – did you come across anything to support Hughes et al? Or any PROOF of the 1:5:200 ratio? I’m doing my MSc dissertation on WLC, and I’ve yet to come across a shred of hard data to support the 1:5:200 ratio, yet it’s referenced everywhere, including in the RICS consultation paper on WLC. Hughes et al. seemed to provide a supported, evidenced argument that this figure is wildly inaccurate – yet I have struggled to find anything in literature suggesting further thought has been given to it. It’s obviously only a ‘rule of thumb’ – but it’s somewhat worrying that it has been adopted on such a wide scale. So again, if you managed to find anything discussing the ratio – either supporting the 1:5:200 rule of thumb, or Hughes et al. – I’d be delighted to read it.



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