1. Change internal door D11 to steel framed silding doors with fixed panel 2. Change external door D12 to steel framed double glazed double doors 3. Change external door D13 to steel framed double glazed sliding folding doors 4. External windows W10 & W11 changed to steel framed double glazed windows in full height 5. New paved path to east, west, and south side of the extension linking with front entrance path and rear terrace