The government has issued an interim draft approved Building Regulations Part L document summarising the decisions taken following the consultation period. <p></p><p>This unusual step has been taken to give industry advance warning of the changes while reserving judgement on a number of issues pending the completion of the Part E (sound insulation) review. </p><p>Planning minister Nick Raynsford pre-empted the publication by announcing that U-value changes would be introduced in a single phase and that wall U-values would be 0.35 (see April edition news). </p><p>But other changes include:</p><p>&amp;•there will be two separate approved documents - one for houses, flats and residential buildings; one for non-domestic buildings</p><p>&amp;• replacement windows, glazed doors and boilers will become subject to control under Building Regulations</p><p>&amp;• higher U-values for windows with metal frames will be introduced (0.22 rather than 0.2)</p><p>&amp;• the poorest acceptable U-value for elements of a wall construction in new dwellings will be 0.7, rather than 0.45 as previously proposed</p><p>&amp;•air leakage (and thermal bridging) for dwellings will be controlled by robust standard details rather than post-construction testing</p><p>&amp;• the &amp;"simplified&amp;" target U-value calculation procedure has been removed </p><p>The DETR said that the interim document is not a further opportunity for consultation on Part L.</p><p></p>