Building Professional Greywater Guide by Art Ludwig(Calif). Installation of greywatersystems in new construction and remodelling. A supplement to the book Create An Oasis With Greywater. How to work within or around building codes to install greywater systems in new construction or remodelling. If your project is going to involve permits, inspections, or building a system for someone else, or if you are a regulator, policy maker, or researcher, you will want this book.