How much material is wasted on a construction project — and what causes it?
UK research going back to Egan puts it at 10% or more of materials per project, with site studies finding actual wastage at roughly double the standard allowances. And a meaningful share of it is not site waste at all: it is over-ordering and duplicate purchase — a procurement-process failure wearing a site failure’s clothes.
The part everybody blames, and the part nobody looks at
Offcuts, breakage, over-mixing, damage in storage — the visible waste, the kind that ends up in a skip and gets photographed for a toolbox talk. It is real, and it is not the whole story.
The invisible waste is the material that was never needed. Ordered twice because two work fronts each raised a requisition. Ordered again because the stock was in the store but nobody could see it. Over-ordered to be safe, and then written off at closeout as dead stock, which is a line item nobody wants to explain.
The duplicate order is procurement’s to own
Site waste belongs to the site. The duplicate order does not — it belongs to a requisition process that did not check live inventory before it became an enquiry.
Which makes it one of the cheapest things on any project to fix, and one of the least fixed. A requisition that checks existing stock — on this site, and on the sister project across town — removes the order before it becomes a delivery, a payment and eventually a skip.
Consolidation helps, and it has a cost
Consolidating small requisitions into one order saves money on minimum order quantities and delivery charges, and it reduces the over-ordering that comes from everybody rounding up independently.
It also delays the urgent lines. On a tight urban site with crane-slot offloading and municipal delivery windows, early over-delivery buys double handling, damage and theft exposure — and late delivery buys idle crews. There is no rule that resolves that. There is only a decision, made per line, against the programme.
References
- module: /modules/material-procurement/ — Egan “Rethinking Construction” and subsequent UK waste studies (MPA 2023)
Zepth is the construction project delivery platform — it runs construction, procurement and asset management on one record, and does the work: reading the drawings, reviewing the submittals, matching the invoices and flagging the risks, with a human sign-off on anything consequential.
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