Many people ask what is included in an SAP report as soon as an architect or building control officer mentions one. The short answer is that it holds far more than a simple pass or fail mark. At Ratio Seven, we prepare these reports for new builds and extensions, so we know how confusing the first one can look. Let us walk you through it, step by step.
A SAP report is the document that comes out of a SAP calculation. The calculation uses the Standard Assessment Procedure, which is the government’s approved method for predicting how much energy a home will use and how much carbon it will give off. The calculation is the work. The report is the proof you hand to building control.
What is included in a SAP report at design stage
The first version is produced before you build, using your drawings and specification. Building control wants to see that your plans will meet the rules before any bricks are laid. A design stage pack usually contains:
- An executive summary showing how the design meets the targets
- The full set of SAP calculation sheets
- A property specification listing walls, floors, roofs, windows and doors
- U-value calculations, which show how much heat each part of the building lets through
- Details of the heating system, hot water, lighting and ventilation
- Any low carbon extras, such as solar panels or a heat pump
- Thermal bridging information, which covers heat lost at junctions in the structure
- A predicted Energy Performance Certificate, where it applies
- A BREL report, where building control asks for one
The report also uses an assumed air permeability figure at this stage. That is simply an educated guess of how leaky the finished home will be. It gets replaced by a real test result later on.
You will need this paperwork for new houses and flats, self-build homes, barn conversions, office-to-residential conversions and some heavily glazed extensions. Our guide for homeowners and developers explains which projects fall into each group.
The key figures that show Part L compliance
Inside the report you will find a handful of headline numbers. Together they show whether your design meets Part L of the Building Regulations. Here is what each one means in plain terms.
Emission rates
The Dwelling Emission Rate is the carbon dioxide your home is predicted to produce. The Target Emission Rate is the limit it has to beat. The target comes from a notional home of the same size and shape, built to a set of baseline values. Your actual design must score the same or better.
Fabric and primary energy figures
Fabric Energy Efficiency measures how well the walls, roof, floor and windows hold in heat. Better insulation, tighter construction and neater junctions all help here. Primary Energy looks at the total energy the home needs across a year, and it gives different fuels different weightings. This is one reason electric heat pumps often score well.
The report also shows a SAP rating, usually on a scale from 1 to 100 or more. A higher number means lower running costs and lower emissions. That rating feeds into the Energy Performance Certificate that buyers and tenants see. To read more about how all of this works, take a look at our page on SAP calculations.
Many designs do not pass the first time, and that is normal. Your assessor can test different insulation levels, heating systems or glazing choices and show you which change gives the best result for the lowest cost. That back and forth is a useful part of the process, not a sign that something has gone wrong.
What changes in the as-built version
When construction ends, the report is updated to match the home you actually built. Things often change on site. A different boiler gets fitted, a window supplier switches, or the insulation thickness is adjusted. The as-built package records all of this. It usually includes:
- Final SAP calculations based on confirmed construction details
- The real air permeability result from the air test
- Updated heating and hot water details
- An as-built BREL report, where one applies
- The final Energy Performance Certificate
If the air test result is much worse than the figure we assumed, the home might no longer comply. That is why we like to check airtightness plans early. Building control uses this final pack to issue its sign-off, and without it the home cannot be marked as complete. We cover the reasons behind all this in why you need SAP calculations.
Most problems we see come from simple causes: wrong insulation details, missing junction information, heating changes that were never reported, or drawings that do not match the specification. Sending complete, accurate information at the start avoids most of them.
FAQs
What is included in a SAP report?
A SAP report includes the home’s specification, U-values, heating and ventilation details, the calculated energy use and carbon emissions, a comparison against the Part L targets, a clear pass or fail, and the rating used for the Energy Performance Certificate. Most projects also receive a BREL report where it is needed.
Is a SAP report the same as an EPC?
No. The SAP report is the assessment of your design. The EPC is the certificate produced from it. You receive a predicted EPC at the design stage and a final one once the home is finished. If you are new to all this, our beginner’s guide breaks the terms down clearly.
Can building control reject a SAP report?
Yes. If the report contains mistakes, or shows that the design does not meet Part L, building control can ask for changes before approval. Fixing the design early is far cheaper than changing a home that is half built. For more answers, read our SAP calculations FAQs.
Get Your SAP Report Right First Time and Keep Your Project Moving
A SAP report is the technical evidence that your home meets the energy rules. It lists the specification, the key emission and efficiency figures, the air test result and the certificates that follow. The design stage version proves your plans are sound, and the as-built version proves the finished home matches them.
If you have a new build, conversion or extension on the way, speak to Ratio Seven today. Send us your drawings, and we will tell you what your report needs to contain, spot any risks early and help you reach approval with fewer delays.
