Sustainability & Green Building Calculators
Embodied carbon, recycled materials, green roofs, Passivhaus and sustainable construction calculators.
Embodied Carbon Calculator
Calculate embodied carbon from material quantities using kg CO2e/kg lookup.
Recycled Aggregate Calculator
Compare recycled vs virgin aggregate with density adjustment and cost saving.
Green Roof Calculator
Calculate green roof substrate depth, drainage board, filter fleece and weight per m².
Rainwater Harvesting Tank Calculator
Size rainwater harvesting tank from roof area, rainfall and daily demand.
Hempcrete Calculator
Calculate hempcrete hemp shiv and lime binder quantities by wall thickness.
Passivhaus Metrics Calculator
Check Passivhaus metrics for space heating, airtightness and primary energy targets.
Whole Life Carbon Calculator
Calculate whole life carbon: embodied, operational and end-of-life per RICS methodology.
Natural Ventilation Calculator
Calculate natural ventilation opening area from stack effect and cross-ventilation.
Thermal Mass Calculator
Calculate thermal mass admittance, decrement factor and time lag by material.
Grey Water Recycling System Calculator
Calculate grey water recycling from shower and basin to WC with treatment and pump.
Living Wall Calculator
Calculate living wall frame, irrigation, planting pockets and water supply.
BREEAM Credits Calculator
Estimate BREEAM credits from design choices for energy, water, materials and ecology.
12 free calculators in Sustainability & Green Building
Sustainability & Green Building Calculators for UK Construction
Sustainability is no longer optional in UK construction - it's embedded in regulation and increasingly demanded by clients. Our green building calculators help you estimate embodied carbon in materials, calculate U-value improvements for insulation upgrades, size heat pumps and solar PV systems, and assess the energy performance impact of your building designs. These tools support both new-build and retrofit projects aiming to reduce carbon emissions and improve energy efficiency.
The 2021 updates to Building Regulations Approved Document L (Conservation of Fuel and Power) introduced significantly tighter fabric performance standards, with the Future Homes Standard expected to mandate even lower carbon heating from 2025. Part O (Overheating) now requires designers to address solar gain and ventilation in new dwellings. Our calculators align with these requirements, helping you assess whether designs meet target U-values, air permeability rates, and primary energy targets. They also support EPC (Energy Performance Certificate) improvement estimates for retrofit projects under MEES (Minimum Energy Efficiency Standards) regulations.
From calculating the payback period on air source heat pumps to estimating the carbon savings of switching from concrete blocks to timber frame, these tools help UK tradespeople and builders make informed decisions about sustainable construction methods. They reference current BRE guidance, SAP calculations methodology, and CIBSE design data to provide practical, real-world estimates that support both your environmental commitments and your bottom line.