The UKs Standard Assessment Procedure
SAP Appendix Q & RdSAP Showers EPC & Part L Compliance
Kelda Showers are recognised within Appendix Q of the UK governments Standard Assessment Procedure and the Reduced Data Standard Assessment Procedure
Kelda’s Air-Powered™ Showers & SAP Appendix Q
As UK housing regulations continue to evolve, reducing water and energy demand within homes is becoming increasingly important. Because hot water use represents a significant proportion of household energy consumption, efficient shower systems can play an important role in improving SAP calculations, EPC ratings, and Building Regulations compliance.
Kelda’s Air-Powered™ showers can be accurately modelled within SAP calculations using Appendix Q, ensuring their real-world efficiency is properly recognised.
This allows developers and specifiers to include Kelda showers with confidence when targeting Building Regulations compliance, particularly in new build and energy-efficient housing developments.
SAP Appendix Q Downloads & Model Qualifiers
Download the SAP Appendix Q Spreadsheet
Use our SAP-approved spreadsheet to model Kelda’s Air-Powered™ showers within your SAP assessment.
Download the Air-Powered™ Shower SAP Spreadsheet
SAP Model Qualifiers
The following Kelda products are approved for SAP Appendix Q modelling:
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– Deluxe Shower Panel – 93XXXXX5
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– Void Shower System – 91XXXXX5
Guidance notes are included within the spreadsheet. If you have any questions, our technical team is on hand to help.
Or
Consult our guidance notes if you have any queries.
Read our guide explaining what SAP Appendix Q is and how it works >
Part L Performance: Energy & Carbon Benefits
Independent SAP test calculations show that replacing a conventional mixer shower with a Kelda Air-Powered™ shower can deliver measurable improvements towards Building Regulations Part L compliance and can contribute towards lower dwelling emission rates in energy-efficient residential developments.
Without WWHRS:
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– Reduced DER and DPER by up to 10 percentage points
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– Achieved minimum emissions and primary energy targets with up to 2 fewer PV panels
When connected to a WWHRS (System A):
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– Reduced DER (Dwelling emission rate) and DPER (Dwellings primary energy rate) by up to 27 percentage points
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– Improved overall SAP score by up to 2 points
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– Achieved minimum emissions and primary energy targets with up to 4 fewer PV panels
By reducing hot water energy demand without compromising shower performance, Kelda’s Air-Powered™ technology helps optimise SAP results and reduces reliance on additional renewable technologies.
*Compliance will depend on the full dwelling specification and SAP model assumptions.
Discover how Kelda supports future-ready, energy-efficient housing developments >
Part G Performance: Water Efficiency & Cost Savings
Reducing hot water demand is one of the simplest ways to lower both household energy use and water consumption.
Kelda’s Air-Powered™ low water-use showers support Part G of the Building Regulations, helping to reduce potable water consumption in homes without compromising the shower experience.
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– Can help lower dwelling water use to 105 Litres per person, per day (LPPPD), in line with 2025 Building Regulations, using the fittings-based approach. With other efficient water fittings, consumption can be reduced to 75 LPPPD.
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– Can help qualify for a water efficiency discount of up to £280 per plot (applied to infrastructure charges by water and wastewater companies).
Additionally, homeowners could see combined water and energy bill savings of around £385 per year, according to the Energy Saving Trust.
*Based on a two-storey, three-bed semi-detached or end-of-terrace dwelling, with space and water heating from a mains-gas combi boiler, including one bath and one shower.
Explore more simple ways to save water at home >
Kelda & RdSAP Recognition
Kelda Showers’ innovative Air-Powered™ technology is officially recognised in RdSAP (Reduced Data Standard Assessment Procedure), the UK’s methodology used to assess the energy performance of homes.
This recognition means that installing Kelda showers can positively influence a property’s Energy Performance Certificate (EPC) rating, supporting more energy-efficient homes and helping developers meet modern sustainability targets.
As homebuyers increasingly prioritise lower running costs and sustainability, technologies that support energy efficiency are becoming a key feature of modern housing design.
We are proud to be the only shower brand recognised within this model, demonstrating our commitment to efficiency, innovation, and Building Regulations compliance.
Learn more about what RdSAP means and how it affects EPC ratings >
Frequently Asked Questions
SAP Appendix Q is a UK methodology that allows innovative energy-saving technologies to be accurately modelled within SAP calculations using independently verified performance data.
Have any questions? Our team will be happy to help.
Guidance Notes
Related Links
What is RdSAP and how Kelda can boost your energy rating
Find Out More
What is SAP Appendix Q and why it matters
Find Out More