This book explores in detail all the key terms that are in everyday use in planning and environmental law. Detailing what the terms mean, where they originate and how they have been interpreted by the courts, this book should prove invaluable. Written in a practical, easy to follow style it explains complex concepts clearly and concisely. The Planning and Development Act 2000 introduced important changes into Irish planning law such as provision for social and affordable housing and these provisions are explored in detail. The new Planning and Development Regulations 2001 are also dealt with fully.