1. RdSAP Conventions version 10.0
Mandatory Learning Module
This module cannot be used as part of an Energy Assessor’s annual CPD requirement as this is a mandatory change to the methodology that all assessors must know

2. Contents Introduction What are the RdSAP Conventions?
Who decides on the Conventions?
New Conventions
Amended Conventions
What does this mean for DEAs?
Further information

3. Introduction
A new set of RdSAP Conventions were released on 17th November 2017 for implementation from 31st December 2017
The Conventions must be followed by all Domestic Energy Assessors completing an RdSAP assessment on an existing dwelling
The RdSAP Conventions have been approved for use by:
Department of Communities & Local Government (England & Wales)
Building Standards Branch, Property Division, Dept. of Finance (N. Ireland)
Building Standards Division, Local Government & Communities Directorate (Scotland)

4. What are the RdSAP Conventions?
Whilst all DEAs strive to ensure that the assessments they complete are as accurate as possible, the assumptions made by the calculation engine produce inherent inaccuracy.
The RdSAP Conventions provide a framework so that all assessors can make the same assumptions based on the circumstances of the property.
The Conventions equalise the knowledge base amongst assessors, allowing newer assessors to produce the same results as more experienced DEAs, with the same basic equipment.

5. Who decides on the Conventions?
The Conventions are drawn up and decided upon by a group which represents the industry as a whole:
BRE – Developers of the SAP/RdSAP specification own by BEIS;
DCLG/Scottish Government/Northern Ireland Executive;
Representatives from the Accreditation Bodies;
Representatives of the DEA organisations (IDEA /Alliance)
By being represented in the group, Quidos can put forward the opinions and concerns of our assessors and include this input in the drafting of Conventions.

6. RdSAP Conventions v10.0 must be used for all lodgements from:
31st December 2017
The current Conventions (v9.0) will still be valid and used for auditing purposes until that date.

7. Q
New Conventions
This section will look at the full wording of the new Conventions

8. Convention 2. 25 Private access stairwell to a single dwelling (e. g
Convention 2.25 Private access stairwell to a single dwelling (e.g. access to upper flats in four in a block dwelling)
If access stairwell separated from the dwelling by an external quality door, - treat stairwell as a corridor.
If there is no external quality door between the dwelling and access stairwell – treat access stairwell as part of the dwelling.
Treat upper flat with an access stairwell as a single storey with the floor area which extends to the perimeter of the access stairwell (at the floor level of the dwelling); record height as the rest of the property.
For the ground floor flat ignore presence of stairwell (treat as external wall).

9. Convention 4.01b Design flow temperature for condensing boilers and heat-pumps
Where known, the design flow temperature should be entered for condensing boilers and heat pumps either from PCDB or SAP Table 4a. This applies to both systems – with radiators and underfloor.
The design flow temperature for condensing boilers should be recorded as unknown unless there is a documentary evidence that the system has been designed and commissioned as a low temperature one.

10. Deleted Conventions
The following Conventions have been delete from the document completely:
3.16 (see 2.24)
4.10
4.16

11. Reviewed – Convention 2.25 Drawbridge method
Where a flat only has ground floor access and the staircase is part of the dwelling, DEAs can use the ‘drawbridge method’ for modelling.
Imagine standing at the top of the stairs and pulling up a drawbridge to cover the stairwell.
This new ‘imaginary floor’ can now be considered as part of the total property floor area.
In this instance, you can consider there to be no corridor and a single door.

12. Reviewed – Convention 4.01b
It is unlikely that on assessment, a DEA will be able to determine the design flow temperature for a boiler or heat pump if not from the PCDB.
Display shows 23° but this is the current flow temperature, not the designed flow temperature
For a condensing boiler, this should be input as ‘unknown’ without appropriate documentary evidence.

13. Q
Amended Conventions
This section will highlight only the amended text within the existing Convention wording.
DEAs should review all the relevant text in the full Conventions document.

14. There have been numerous amendments made to the Conventions for this release:
1.01;
2.18;
3.07;
4.03;
6.05;
1.04a;
2.22;
3.08;
4.04;
6.06;
2.01;
2.24;
3.09;
4.09;
7.01;
2.02;
2.25;
3.10;
4.13;
9.01;
2.03;
3.02;
3.11;
4.17;
9.05;
2.04a;
3.03a;
3.12a;
4.18;
9.06;
2.04b;
3.03b;
3.12b;
4.19;
9.08;
2.06;
3.03c;
3.14;
5.01;
9.09;
2.13;
3.04;
4.01a;
5.02;
9.13;
2.14;
3.05;
4.01b;
6.03;
9.14
2.15;
3.06;
4.02;
6.04;

15. Convention 1.01 Use of RdSAP
RdSAP is used to produce Energy Performance Certificates (EPCs) for existing dwellings only.

16. Convention 1.04a Self-contained dwelling attached to or forming an extension of another building
A building unit designed or altered for separate self-contained use could be indicated by the accommodation having its own cooking and bathing facilities and its own access (from the outside, or via a communal corridor, without having to enter via the main dwelling), and may have separate or shared provision of heating and ventilation. Also, the presence of an internal connecting door between two dwellings will still qualify the dwelling as being self-contained.
An example might be a self-contained flat in a building.
If the ‘annexe’ is not self-contained see 1.04b.

17. Convention 2.02 Precision of lengths
Measure to two decimal places (0.01 m) or better.

18. Convention 2.13 Alternative wall
An alternative wall can be:
(i) A sheltered wall (to unheated corridor), or
(ii) A wall that has a construction type or heat-loss characteristics (U-value) different from the main external wall
Always include the alternative wall in the assessment in case (i);
and disregard it in case (ii) if it is less than 10% of total exposed wall area of the building part (including windows and doors).
If there is both a sheltered wall and one with different construction type or U-value, treat the sheltered wall as an alternative wall and split the dwelling into two parts to allow for the wall with the different construction type or U-value.

19. Convention 2.14 Definition of a “window”
A window is an opening in an external wall or roof of a building, fitted with glass or similar material, usually in a frame, that admits light. If it can be opened, then it is primarily to admit fresh air and not to provide entry into the property (with the exception of patio doors).
Patio doors may be treated as windows due to the high ratio of glazing in relation to the area of the whole opening.

20. Convention 2.24 Party wall lengths
To be recorded in all cases where a party wall is present.
A party wall is any wall between the dwelling and:
- another dwelling;
- commercial premises;
- a heated corridor or stairwell in blocks of flats;
- a heated common area.
Note: a heated corridor is one with controlled fixed heaters; heat from distribution pipes is disregarded.

21. Convention 3.04 Access to loft insulation and rafter insulation
If the loft, or part of the loft, is boarded and the assessor can establish and evidence the insulation present under the boards at multiple locations below the boarded area (visible through gaps or extending in from the edges) the boarded area is treated as insulated to the thickness that can be proved by the evidence.

22. Convention 3.12a Glazing age
Choose unknown date if there is no evidence of the date.
Multiple glazed units can be dated via the following methods:
a) The manufacturing date on the spacer bar, or possibly on the frame.
b) There is documentary evidence confirming the date of installation of the window e.g. FENSA / CERTASS / Building Control certificate or manufacturers guarantee.
c) Property build date if after the following trigger dates: Post 2002(E&W), (Scotland) or 2006(NI) where applicable.
If none of the above applies choose ‘unknown’.

23. Convention 4.17 Time and Temperature Zone Control (TTZC)
A system of controls that allows heating times of at least two zones to be programmed independently, as well as having independent temperature control.

24. Convention 6.05 Enclosed hot water cylinders and insulation of hot water cylinders
If factory insulated plus a jacket, measure the thickness of foam insulation plus 1/3 thickness of the jacket.

25. Convention 9.13 Electricity meters
Usually the dwelling uses either single-reading meter or a multiple-reading meter arrangement. Older properties may have two single-reading meters to record on-peak and off-peak readings (record as dual meter).
If tele-switch or time-switch is present – treat as dual.

26. Review of Amended Conventions
Assessors should refer to Scheme Guidance about the use of RdSAP or SAP. All buildings completed after 6th April 2008 should be completed using the SAP methodology; this includes any dwellings split up or added together to form new dwellings.
Convention 2.02
All measurements must be made to a precision of 10mm. These measurements should be input as, for example, 2.32 m and not 2.3 m.
Convention 2.24
The types of party walls have now been instilled directly into the Conventions, such as a heated corridor. It was never clearly specified in the Conventions that these were to be treated as party walls.

27. Review of Amended Conventions
Convention 3.12a
The Conventions Group has made it very clear now about how DEAs should be inputting glazing age into the software. The previous ambiguity and contradiction has been removed.
Convention 6.05
The assumptions made for instances where a cylinder with factory- applied foam as well as jacket have been simplified to ensure that all DEAs are following the same process. The total insulation input for the cylinder would be:
𝑇𝑜𝑡𝑎𝑙 𝑖𝑛𝑠𝑢𝑙𝑎𝑡𝑖𝑜𝑛=𝑡ℎ𝑖𝑐𝑘𝑛𝑒𝑠𝑠 𝑜𝑓 𝑓𝑎𝑐𝑡𝑜𝑟𝑦 𝑓𝑜𝑎𝑚 𝑡ℎ𝑖𝑐𝑘𝑛𝑒𝑠𝑠 𝑜𝑓 𝑗𝑎𝑐𝑘𝑒𝑡

28. Please remember to review ALL Convention changes to ensure your professional knowledge and understanding of the changes

29. What does this mean for DEAs?Q
What does this mean for DEAs?

30. What does this mean for DEAs?
On the face of it, there are a lot of changes made in this new version of the Conventions, but the majority are refined wording or evidencing requirements.
The Conventions should be seen as part of an assessor’s on- site equipment. DEAs should consider bringing a printed copy of them with them to each assessment they undertake to ensure that the correct methodology is undertaken.

31. Further information
The new RdSAP Conventions are available to download from iQ-Energy, the Quidos Support Log, and in accessible formats on request.
Should you have any questions about these changes, your first point of contact should be our Support Log; either or log your query to
Don’t forget to try the Conventions Quiz in iQ-Energy.
Please remember that these Conventions should be used from 31st December The previous release will still be used for lodgements and QA purposes up until that date.

32. Thank you for reading