[ABSTRAK Makalah Non Skirpsi ini membahas tentang Peraturan hemat air yang mewajibkan instalasi tangki air hujan untuk semua bangunan baru. Namun kebijakan tersebut dianggap memiliki banyak kelemahan karena NPV analisis efisiensi regulasi dengan menggunakan nilai terbaik hipotetis dan kelompok rujukan agregat keuntungan bersih adalah negative. Itu sebabnya, beberapa kelompok orang meminta pemerintah untuk mencabut peraturan tersebut. Untuk mengetahui apa tindakan terbaik pemerintah yang harus diambil, maka laporan ini melakukan sebuah analisis biaya dan manfaat mempertahankan peraturan yang ada bukan menghapusnya. Panjang diasumsikan regulasi dipertahankan adalah 25 tahun.ABSTRACT The water saving regulation that makes mandatory the installation of rainwater tanks for all new buildings is considered has many drawbacks since the efficiency analysis NPV of the regulation by using best hypothetical value is and aggregate referent group net benefit is negative. That?s why, some group of people are asked government to repeal the regulation. In order to know what best actions government should take, this report undertakes a BCA of retaining the existing regulation rather than removing them. The assumed length of retained regulation is 25 years., The water saving regulation that makes mandatory the installation of rainwater tanks for all new buildings is considered has many drawbacks since the efficiency analysis NPV of the regulation by using best hypothetical value is and aggregate referent group net benefit is negative. That’s why, some group of people are asked government to repeal the regulation. In order to know what best actions government should take, this report undertakes a BCA of retaining the existing regulation rather than removing them. The assumed length of retained regulation is 25 years.]