Part L1B – Conversions.
Summary of Methods to Demonstrate Compliance for Conversions
Reference method
- Demonstrate new thermal elements meet the minimum compliance standards (see App B).
- Demonstrate new controlled fittings meet the minimum compliance standards (see App A).
- Demonstrate any retained thermal elements meet the minimum compliance standards (App C).
- Demonstrate the opening area does not exceed 25 percent of the extension floor area in addition to the area former openings.
- Any openings with a u-value greater than 3.3 require replacement.
SAP calculation
- Demonstrate the CO2 emission rate of the dwelling is equal to, or lower than, a notional dwelling that meets the minimum compliance standards for thermal elements and controlled fittings. Using this method a dwelling would not need to meet all the conditions of the reference method.
