As the UK transitions toward the Future Homes Standard, our team set out to understand how much it costs to deliver some of the most impactful whole life carbon reductions in a typical new home. Bringing together the carbon, cost, and carbon efficiency calculations in an easy to understand way was our challenge:
"What this paper makes clear is that cutting whole-life carbon isn't always a cost burden, it's a smart investment. With most measures either cost-neutral or delivering savings, at Property Box Finance we're committed to backing developers who want to build sustainably."
- Sarah Milne, Chief Executive, Property Box Finance
Our findings show that most embodied carbon reduction measures are cost-neutral—and implementing all the identified opportunities would add only around 10% to the total build cost of a standard three-bedroom house. Importantly, this house would have significantly (potentially zero) energy bills.
Study Overview
Using the ‘Future Homes Embodied and Whole Life Carbon: 2023–2025 Implementation Plan for the Homebuilding Industry’ as our benchmark, Construction Carbon carried out cost assessments through our in-house quantity surveyors.
We used Building Cost Information Service (BCIS) benchmarks and manufacturer data to model a 100 m², two-story, three-bedroom home, comparing a range of lower-carbon specification options.
The results demonstrate that meaningful reductions in embodied carbon (measured in kgCO₂e/m²) can often be achieved without materially increasing construction costs—and in several cases, they even save money.
Baseline
- Embodied carbon intensity (A1-A5): 435 kgCO₂e/m²
- Estimated build cost: £231,000
Alternative materials and systems were assessed across key building elements—outer and inner leaves, floor systems, roofing, and services.
Carbon reduction options - upfront carbon intensity
Outer Leaf Options
- Lightweight Fibre-Cement Cladding (Option 1b):
- Reduces embodied carbon to 398 kgCO₂e/m² (a 37 kgCO₂e/m² reduction)
- Cost saving: ~£2,547
- A standout opportunity combining lower carbon and lower cost
Inner Leaf Options
- Timber Frame Inner Leaf (Option 2a):
- Reduces embodied carbon to 363 kgCO₂e/m² (a 72 kgCO₂e/m² reduction)
- Cost increase: ~£12,261 (£1.01 per kgCO₂e saved / £1,014 per tonne)
- Also offers programme advantages with quicker weatherproofing and predictable timelines.
Intermediate Floors and Floor Systems
- Offsite Floor Cassette (Option 4a):
- Small carbon reduction with a minimal cost uplift (~£104)
- Offers precision, consistency, and time savings not captured in simple cost models.
- Beam & EPS Infill Floor System (Option 3a):
- Slight cost rise (~£847) with a moderate carbon reduction—a practical, low-risk improvement.
Roof Covering
Options such as fibre-cement slates (5c) and concrete tiles (5a) show marginal differences in both cost and carbon relative to baseline. Roof covering choices generally do not materially drive cost increases, even when chosen for carbon benefit.
2. Low- Whole Life Carbon Services: Air Source heat Pump, (ASHP), Photo Voltaic (PV) and Battery Storage
While the primary focus of this study is embodied carbon, service systems like air-source heat pumps (ASHP) and solar PV with battery storage play a major role in reducing operational carbon—a key component of total whole life impact. (WLC Intensity kgCO2e/m2).
Carbon reduction options – Whole life carbon intensity
ASHP Only (Option 6a):
- Cost uplift: ~£2,318 vs gas boiler
- Delivers long-term efficiency gains and aligns with forthcoming regulations.
ASHP + PV (Option 6b):
- Cost uplift: ~£6,397
- Provides significant operational carbon savings and energy bill reductions.
ASHP + PV + Battery Storage (Option 6c):
- Cost uplift: ~£14,400
- Maximises carbon and cost savings over the building’s life and supports future grid flexibility.
None of the low-carbon service options produce prohibitive front-end costs, especially when framed against lifetime energy savings and incoming regulation.
Key Insights
- Many embodied-carbon reduction strategies cost less than 1% of overall build cost.
- Some—particularly the lightweight cladding—reduce both carbon intensity and capital cost.
- Higher-impact changes, such as timber frames, come at a modest 5–6% increase but yield significant sustainability gains.
- Low-carbon systems like ASHPs and PV arrays enhance long-term performance and appeal, with energy savings offsetting initial investment.
When all measures are combined, whole life carbon reductions can be achieved for roughly a 10% increase in build cost, which is a modest premium for a substantial carbon benefit.
Full costing table
Acknowledgments:
The team at Construction Carbon gratefully acknowledge:
- Adam Graveley and all the contributors to the “Future Homes Embodied and Whole Life Carbon: 2023-2025 Implementation plan for the homebuilding industry” report published by the Future Homes Hub.
- Josh Gamston at Woodforde Scott for costing support.
- Tom Brown at Ingenious Real Estate Finance for continuing support.