How It Works
The design fabric specification that has been input into the design section of the building control system for a particular dwelling will automatically populate the as constructed onsite and on line compliant documentation in the building control system.
The stakeholder but more importantly the builder uses their project ID for a particular dwelling to access the online as constructed documentation and download the customised onsite fabric compliance documents for the registered dwelling. The builder downloads the construction details that are being used on this particular project and then uses them to check the detail on site.
The builder uses these customised onsite fabric checklists to ensure all the construction details are checked for good workmanship in relation to integrity of the insulation, y factor detail and air permeability. When the as constructed fabric specification is equal to or better than the design fabric specification then the compliance boxes are ticked and the documentation can then be signed off and dated by the Builder. These on site checklists and air permeability test results need to be forwarded by the Builder to the administrator/assessor of the building control system.
When the administrator/assessor receives the onsite fabric checklists and air permeability results, he informs all the stakeholders of the actual as constructed fabric specification by editing the as constructed fabric online compliance documents, ticking the compliance boxes for the fabric and inputting the actual air permeability result, if there is an improvement on the design fabric specification it will be noted online.
The administrator informs the registered stakeholders that the online and onsite fabric compliance documents have been completed and are ready for inspection by sending an automatic e mail through the building control system, it is then the responsibility of the stakeholders to check the detail on site or request onsite fabric compliance documentation and air permeability test from the builder/administrator.
Can the design Y factor be used:
If all the y factor compliance boxes are ticked in these documents then the design y factor can be used to calculate the as constructed DER. If the compliance boxes are not tick or if no compliance documents for the y factor are provided, then the assessor will have to use the default figure of 0.15 W/m2K to calculate the as constructed DER. If the as constructed drawings are different to the as designed plans then the y factor should be recalculated and used to calculate the as constructed DER, if y factor compliance documents are available to the energy assessor.