How to Energy Rate a Property
The SAP (standard assessment procedure) report is the UK Government’s system that they use to determine the energy rating of UK residential properties. It was set up to provide an accurate way to calculate how much energy a home will consume as well as how much carbon dioxide will be emitted based on standardised occupancy conditions, which in turn allows for a like for like comparison from home to home. In short, the SAP tries to calculate the energy costs per unit of space and rough costs of water heating.
Why does this report exist and where did it come from?
The initial report was introduced back in 1995, and since then it has been reviewed and updated several times. One of the most significant updates happened in 2005 when carbon dioxide emissions were added. The initial report was developed from the National Home Energy Rating scheme, which was used mainly back in the 1980s.
Since 1995, every new-build property required a SAP rating, but full reports didn’t need to be submitted until 2005. It was not until April 2006, when SAP calculations were made a requirement for all new-build residential properties. It is widely expected that the SAP regulations will be updated against shortly to keep up with recent developments.
Currently SAP 2005 is used as a basis for checking compliance with the UK building regulations Part L, which is the section covering the conservation of fuel and power.
How is it calculated?
A number of factors are taken into account when the SAP is drawn up, but the report is independent of household size, ownership of particular electrical appliances and individual heating patterns as these are all subjective.
These are the points that are taken into account:
- If the property intends to have renewable energy technologies
- If there is energy space for cooling
- What materials had been used for construction
- If there is any thermal insulation
- If there are any solar gains through openings in the building
- Control and efficiency of the heating system
- How well the property is ventilated
- What fuel is used to provide heating, ventilation and lighting
Based on the above, the property is awarded with a number from 1-120 (SAP rating) based on expected yearly energy costs for space and water heating. It is then rated with another figure from 0.0 to 10.0 based on the potential carbon dioxide emissions. Once both numbers have been awarded, the latter figure is compared against the government’s target carbon dioxide rate to see if it can be awarded with a pass.
Ratings are not affected by the location of the household, which means that every property has the same rating in all parts of the UK.
How are they carried out?
Reports have to be calculated and submitted by accredited and fully trained SAP assessors. If the report is not carried out, then the building cannot be granted a Building Control Completion certificate. All new builds are required to have a full SAP report. However, some extensions and major alterations also require their own report. Extensions or conversions where the glazed area is over 25% of the total floor area require a SAP report if the property does not already have one.
In any event, SAP reports need to be produced at the planning stage before any work gets underway. This allows alterations to be made while the building is in progress rather than retrospective alterations that would be costly to implement. The quicker the report is carried out the better because the figures allow energy efficiency to be considered while the property is being designed. This allows the designers to come up with a cost-effective solution.
The SAP report for existing properties is carried out in the same way as a new property. The calculation is formed on an assessment of the property and nothing else. Even when there are people living in the property and the numbers are significantly different, in order to remain fair it is the property that is taken into account because living figures can deviate. In order to calculate the figures of an existing property the full floor plans are required.
Why is SAP report required?
A SAP report is required to show that a property is compliant with energy performance figures set out by the government. As mentioned the property is designated a figure from 1-120 and a separate figure from 0.0 to 10.0. This ‘scheme’ is part of a wider goal to increase the UKs energy efficiency in the long term.
What information is required to obtain an SAP report?
In order to receive a report the assessors require drawings of the property and the full build specifications. This means that floor plans, elevations, sections and site plans are all required before a figure can be assigned.
Hopefully, you now understand more about SAP reports. Of course, if you have any questions, please do not hesitate to contact us to discuss them.