謝謝老貓的及時回複，還有一個問題

那就是現在他們批準我們沿著後院的溝建圍欄，以解決那裏safety issue (信中是這樣寫的：Council has provided landscaping guidelines which will meet the safety issues of your family, in particular, the ability to put fencing as defined by the guidelines.) 既然fence是建在common property上，解決的是safety issue, 費用是否應該由他們付？非常感謝您專業的意見！