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Organisation
Industry
Company size
Results
design optimisation
55% superstructure carbon reduction
tender response
Nearly 31% offered vs 20% asked
carbon data at scale
50 tenders in one year
Challenge
Solution
A team of architects and engineers runs LCAs and design optioneering in One Click LCA, comparing design options side by side in days rather than weeks. Every project feeds an in-house dashboard built on One Click LCA data, so the team can benchmark new options against past projects instantly rather than starting each comparison from scratch. That speed is what lets Sisk turn around costed, credible carbon options within tender timescales.
Outcome
"The client was asking for a 20% carbon reduction that was in the tender. And what we did is give them options that could achieve nearly 31% for them to consider and decide which of these they wanted to implement."
Why a contractor built a design team
John SISK & Son, the Irish Tier 1 contractor, employs a 10-person Integrated Sustainable Solutions team of architects and engineers led by Juan A. Morillas, Head of Sustainable Design. Speaking at One Click LCA’s Carbon Experts Summit in London, Juan A. Morillas explained that the team exists to answer a commercial question, not a compliance one.
Clients increasingly write carbon into tenders, and the requests have become more specific than a target on a cover page. A well-structured tender now typically asks for a costed carbon reduction proposal, an assessment of whole life carbon impacts in line with Greater London Authority whole life carbon requirements, and a description of how carbon will be tracked from an as-designed estimate at tender stage through to an as-built figure once the building is complete, scored as marks rather than treated as a pass or fail condition. SISK works with clients across these requirements, and contractors use LCA to win work as much as to report it. In one tender Juan A. Morillas showed, "10% of the marks were related to green procurement and sustainability." That weighting changes the economics of bidding.
“It can make you win or lose a tender because it’s impossible to achieve a 10% difference in cost,”
- Juan A. Morillas, Head of Sustainable Design at John SISK & Son
Design first, materials second
SISK’s method starts with design optimisation, then material optioneering. In one tender, the client asked for a 20% carbon reduction. Sisk responded with a one-table summary of costed options that could achieve nearly 31%, each marked with its carbon, cost, and programme impact, so the client and design team could choose what to implement.
The headline example is a data hall steel superstructure. The baseline design used heavy I-sections below a deep ceiling void that worked only as a plenum. SISK’s team checked the MEP design, found no large ducts crossing the space, and proposed a truss that used the void structurally.
“With the optimised design, the carbon could go down up to 55%. And it’s just because there is half the steel.”
- Juan A. Morillas, Head of Sustainable Design at John SISK & Son
Key takeaway: The redesign halved the amount of steel required, reducing embodied carbon from 32,345 to 14,594 kgCO2e, a 55% reduction at no additional cost, with further reductions available through reused steel content.
One dashboard for every project
Each assessment follows recognised methods such as the RICS whole life carbon assessment standard, and the results feed SISK’s in-house carbon dashboard, built on data from One Click LCA’s life cycle assessment software for design and construction. The dashboard lets the team compare every live LCA against the rest of the portfolio and report as-built carbon during construction. The team stays small by design. “We work as a team and then we move to where the need is,” Juan A. Morillas said. Last year, that meant around 50 tenders, 15 LCAs, and 20 to 30 design optimisation exercises.
Looking ahead
SISK continues to expand its carbon dashboard and as-built reporting, and is supporting industry demonstrators for lower carbon concrete and homegrown timber so that proven products reach projects faster.
TIP: BENCHMARK EVERY PROJECT, NOT JUST ONE
Compare live projects against your whole portfolio with LCA software for design and construction and lock in reductions before stage 3 with early design decarbonisation tools.
FAQ
Why do contractors run their own embodied carbon assessments?
Contractors run embodied carbon assessments to win work and de-risk delivery. Carbon now carries scored marks in tenders, and contractors who table costed reduction options gain an edge no pricing strategy can match. SISK runs its assessments in One Click LCA and benchmarks results across all projects.
How much embodied carbon can design optimisation save?
Design optimisation can cut embodied carbon far more than material swaps alone. SISK reduced a data hall steel superstructure’s embodied carbon by 55% at neutral cost by redesigning the structure. Tools such as One Click LCA let teams compare design options quickly enough to use them at tender stage.
What is a whole life carbon assessment in a tender?
A whole life carbon assessment quantifies a building’s carbon across its full life, following standards such as the RICS whole life carbon assessment standard. Tenders increasingly require one as a baseline for reduction targets. One Click LCA automates whole life carbon assessments for buildings and infrastructure.
What does SISK use One Click LCA for?
SISK uses One Click LCA to run project LCAs, then feeds the data into an in-house dashboard to compare every live project and report as-built carbon during construction. This supported around 50 tenders, 15 LCAs, and 20 to 30 design optimisation exercises in one year.
