In March 2015, the French government passed a law that is set to change the face of France's cities. The law states that the roofs of all new buildings in commercial zones must be covered in part with either plants or solar panels.

The benefits of these so-called rooftop gardens are many. They will help cut the amount of energy needed for heating and cooling the buildings in summer and winter. The plants on green roofs will help filter unpleasant gases, thus cleaning the polluted city air. The soil used to grow the plants will also help retain rainwater. This will make problems with runoff—such as the flooding of sewer systems—a lot rarer. In addition, these rooftop gardens will give birds a place to nest in an otherwise unsuitable city environment. And of course they will create new community areas in cities where space is limited.

French environmentalists wanted the law to state that plants should completely cover the roofs of all new buildings. However, as a first step, the government decided to limit the law’s power so that only commercial buildings would be affected. The government also suggested giving businesses the choice of fitting solar panels onto their roofs to generate their own power rather than growing plants. This would give businesses the chance to cut their own carbon footprints.

France is now one of many countries, including Germany, Australia, and Canada, that use green roofs to lower their negative effect on the environment.

法國政府於2015 年3月通過一項法律，意欲使法國的城市脫胎換骨。這條法律規定商業區的新建大樓屋頂，必須規劃一部分種植物或裝設太陽能板。

這些「屋頂花園」有許多好處，能夠讓大樓冬季減少暖氣的使用，夏季減少冷氣耗能。綠屋頂上的植物還能過濾髒空氣，改善城市空氣污染。種植栽的土壤也有利於雨水貯留，減少地表逕流問題（例如下水道系統溢流）。此外，屋頂植被讓鳥類於不利棲息的市區環境裡，能有築巢的地點。而且也可在寸土寸金的城市空間中，開創新的公共區域。

法國環保人士原本的提案，是希望新建築屋頂上必須一律覆滿植物，但政府決定第一步先折衷，僅綠化商業區內的建物。政府也建議業者，若不種植植物，可選擇在屋頂安裝太陽能板，自我發電，此方案也給企業減少碳足跡的機會。

法國是目前實施綠屋頂以降低對環境破壞的眾多國家之一，其他已施行的國家還包括德國、澳洲和加拿大。