Related content
| Building: Walls | ||
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Guidance on re-use of data for Walls can be found here |
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| Data Entry Item | Guidance | Documentary Evidence |
| Wall area | Internal areas must be measured and recorded using dwelling sketches or architectural drawings. |
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| Heat loss wall U-values |
It may be possible to gather information on site in relation to the dwelling walls and wall type and this information must be used where available. A filled cavity wall may show drill marks above, below and to the sides of each window and spread out across larger wall sections. These marks are typically filled with mortar. If using the presence of these marks as evidence of cavity wall fill insulation, they must be visible on each facade for which the filled cavity wall U- value is to be applied. To substantiate a non-default U-value for a cavity wall, the Assessor can measure thickness of retrofitted cavity fill insulation at meter box. Where insulation is not accessible, documentary evidence of type and thickness of installed insulation and other layers in the building element in question should be used where available. When using documentary evidence, the documentation must indicate that the entire heat loss surface has achieved the non-default U-value |
For non-default U-values:
or, Copies of Invoices with detailed description of materials (e.g., insulation type, thickness, and quantity); or, Declaration of works for SEAI grant schemes showing area of surface insulated, insulation thickness and type; or, |
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Where there is insufficient information available to calculate U-values, then defaults should be used For opaque curtain walling please refer to Heat loss window U values. If the wall type is unidentifiable, you must assume that the wall is “unknown” wall type. |
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Examples of inadequate substantiation of non-default U-values are given in Table 2.20. The procedures for Existing and New Final BER assessments require that BER Assessors carry out a full building survey to collate and verify data for assessment before publishing the BER.
Table 2.20 - U-value substantiation
| Issue | Non-Compliance detail | Correct U-value detail |
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| The thermal conductivity value used to calculate the U-value of the retrofitted wall is not the same as the Agrément certificate value. | The insulation contractor certificate states a thermal conductivity of 0.033 W/mK and references NSAI certificate 06/0168. The NSAI cert states a thermal conductivity of 0.035 W/mK. | Either the NSAI cert number is incorrect or the incorrect thermal conductivity has been used in the U-value calculation. Considering no further evidence is presented the correct thermal conductivity of 0.035 W/mK from the NSAI certificate is used. |
| A U-value of 0.29 W/m2K has been entered in DEAP by the Assessor based on contractor input to the Declaration of Works form for cavity fill insulation under the Better Energy Homes Scheme. | No Assessor U-value calculation provided or evidence to specify the exact insulation type, thickness, and certified evidence of thermal conductivity. A contractor’s statement of U-value is not acceptable alone but must be accompanied by full calculations. | In the absence of acceptable documentary evidence, the U-value defaults to filled cavity value of 0.6 W/m2K (this reflects the construction age of the dwelling). |