The Business Technician Education Council (BTEC) standard unit in Building Services and Equipment for the award of the higher diploma or certificate, requires the student to develop an appreciation of the principles of services design in various specific areas. This volume has been written for students studying for the standard unit and the text covers closely the requirements of the TEC syllabus. Students in building, architecture and surveying studying for the higher diploma or certificate should, therefore, find this volume a useful addition to "Building Services and Equipment", volumes 1 and 2. The book should also be of assistance to students studying for the Chartered Institute of Building and the Royal Institution of Chartered Surveyors' examinations in services. The text covers, by carefully selected worked examples, the principles of services design, and the questions, with answers at the end of each chapter, should help the student to obtain a better understanding of the topics covered. While primarily intended for the student attending lectures, the book is also designed so that the reader will have little difficulty in studying the subjects covered in private study. Practicing technicians in building, architecture and surveying should also find the book useful by providing an appreciation of the design of building services. SI units are used throughout the book and a description of the units has been included. Wherever possible, diagrams and tables have been included to supplement the written descriptions and calculations.