Building Services Design Methodology

A Practical Guide

David Bownass, D. Bownass

• Publisher: Routledge
• Year: 2002
• Print ISBN: 9781138149304
• eBook ISBN: 9781135803407
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

Building Services Design Methodology clearly sets out and defines the building services design process from concept to post-construction phase. By providing a step-by-step methodology for students and practitioners of service engineering, the book will encourage improved efficiency (both in environmental terms and in terms of profit enhancement) through better project management. Generic advice and guidance is set in the current legal and contractual context, ensuring that this will be required reading for professionals. The book's practical style is reinforced by a number of case studies.

Chapter I

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Introduction

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1.1 Chapter contents

The topics covered in this chapter include:

• The aim of the book
• How to use the book

1.2 The aim of the book

The design of building services systems has changed considerable in the last 20 years. The change in approach, procurement, design tools and legislation has been phenomenal.

The consultant's role has changed from the authoritative adviser to a provider of design services and information. At the same time the industry has tended to segment into large design consultants, small niche design practices and a huge range of specialist subcontractors providing design and installation packages. Designers are no longer simply required to sit at a drawing board, produce designs and advise the client of their needs. There are few, if any drawing boards left in modern design offices! The designer is more likely to be sitting at a computer editing a document or integrating specialist suppliers' packages into the design solution or presenting the design to the client. The designers' skills have expanded from a simple emphasis on technical knowledge to include information technology skills, communication skills, presentation skills, finance and design management.

The procurement route for construction work has also changed. Design and build and its many derivatives now appears to be the main procurement method. The traditional, architect led contract is now the exception rather than the norm.

Design tools have evolved beyond recognition. Drawing boards, manual hand calculations, drawing pens, log tables, carbon copies and typewriters have all been replaced by the computer and information technology. Almost all drawing is now on computer aided design (CAD) stations. Computers are used for most calculations, they provide access to a growing range of information on the internet and act as the main means of exchanging information through e-mail and project document management systems. They can even model the design solution before it is built! Although teleconferencing is still not commonly used within the industry, mobile communications particularly mobile phones are accepted as a standard accessory. The use of letters has declined dramatically. They are only used for official correspondence as a record of events; the fax and increasingly e-mail have superseded them.

Legislation affecting design has increased significantly. The vast majority of this legislation relates to health, safety and the environment. More subtly, the legislation implementation has changed, shifting the emphasis onto the designer. Legislation used to be prescriptive, e.g. guards shall enclose all rotating machine parts. Current legislation is descriptive placing a duty on the designer to use ‘a reasonably practicable’ approach in defining the solution.

In summary, design services in the early twenty-first century are procured rather than appointed, the designer's skill base has broadened, there are more routes to procuring construction projects, information technology is an integral part of design work and there is more legislation affecting design. All these fundamental changes fit within a business culture that is more competitive, more global and a lot faster; time to market is often critical.

While the changes are significant, the rate of change is likely to accelerate. This is because the construction industry has been relatively slow to grasp the ‘service culture’ and starts from a point well behind other comparable industries. For instance, new teams of people are formed for virtually every project, financial disputes are still common place, construction productivity remains low and employment can be erratic.

There are a number of business and design issues that will force further change on the industry. The key business issues are global competition, alternative government procurement strategies, e.g. private finance initiative, and the consequences of the Egan Report. The Egan Report is currently being considered by the construction industry and it is likely to have a significant impact on design and the approach to design work. The key design issues in the immediate future are the need for ‘sustainable’ design solutions and the impact of information technology, both in the creation of new products and new design tools.

Within this environment of continuous change, designers need to look forward and consider how they can improve their design process as part of improving the performance of the construction industry. Logically, before any work can start on improving the design process the current process needs to be defined. This will provide a number of benefits, including:

• establishing a common understanding of the design activities
• defining a minimum standard for good design practice
• clarification of the terms used in the various stages of the design
• improving communication; and most importantly
• confirming the starting point for improving the design process

The aim of the book is to provide the first step by defining the design process. Surprisingly the current building services design process does not appear to be explicitly defined in any existing texts. How the design process can be improved is a much more complex issue that will involve debate across the industry and some innovative thinking.

1.3 How to use the book

Although the book is written as a continuous work that can be read from start to finish, it is likely that practising designers who are short of time will use the book as a reference tool, dipping into the chapters infrequently as a type of check list. For these people, read Chapter 2 particularly the sections on responsibilities and then Chapter 3 as it provides an overview of the whole process. The other chapters can then be sampled as your work progresses through the various design stages. For those people who are studying the design process to understand how it works or to improve the process then the book will probably need to be read as a whole. Reference texts and further reading are provided at the end of each chapter and these will provide additional information, particularly the BSRIA documents.

Chapter 2

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The building services designer's role and responsibilities

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2.1 Chapter contents

The topics covered in this chapter include:

• An explanation of mechanical building services systems
• Designer's legal responsibilities
• Designer's contractual responsibilities
• Designer's professional responsibilities.

2.2 Mechanical building services systems

The range of building services systems a designer is likely to experience is directly reflected in the purpose of the employer's business. A company specialising in feasibility studies and concept designs for the retail market will have a very focused range of building services work, while a design and build company operating in all the market sectors will probably have a very varied range of work.

Different organisations also package different engineering subjects into mechanical building services engineering. For the purposes of this book the scope of building services is defined as:

• HVAC (heating, ventilating and air conditioning)
• Mechanical fire protection
• Utility services
• Noise control

These subjects are described in more detail below.

2.2.1 Heating, ventilation and air conditioning (HVAC)

Any system involved with heating, ventilating or air conditioning inside a building falls into this category [1]. The primary mechanical systems that can apply to any project are presented in Table 2.1.

Table 2.I Typical HVAC systems

System	Description
Piped services
Low temperature hot water (LTHW)	Heating plant and pipework distribution systems with radiators, fan coils or heater batteries, etc. These systems can be subdivided into either constant volume, variable temperature or variable volume, constant temperature
Domestic water services	Hot and cold water to basins, sinks, baths, showers, vending machines, etc. including potable and non-potable water systems
Chilled water	Chillers and pipework systems for distributing chilled water for cooling air before it is passed into an air conditioned or comfort cooled space and to cool process plant and equipment
Direct expansion refrigerant	A piped system transporting refrigerant acting like a freezer although operating in reverse to cool a space. Refrigerant systems extend from small individual room cassettes to cold rooms for product storage
Cooling tower water	Cooling towers or air blast coolers (indirect cooling coils) and distribution pipework frequently used to provide a heat sink for liquid cooled chiller plant
Steam and condensate	Steam generation and distribution pipework for heating, sterilising, and humidifying with liquid condensate recovery return pipework
Compressed air	Compressor equipment and piped compressed air for operating machines, control devices, etc.
Specialist water treatment systems	De-mineralised, reverse osmosis, distilled, de-ionised water, etc. and associated water treatment equipment
Specialist gas systems	Carbon dioxide, nitrogen, hydrogen, etc. Usually supplied through specialist subcontractors
Vacuum systems	Vacuum cleaning systems primarily used in industrial process and health care facilities. Usually supplied through specialist subcontractors
Above ground drainage	Soil waste drainage from sanitary accommodation
Above ground process drainage	Drainage from process plant, wash down areas and
	laboratories that will probably require on site treatment before discharge to the local authority sewage system
Rainwater drainage	Rainwater drainage from roofs discharging at ground level into below ground drainage systems
Natural gas	Natural gas pipework distribution from the service provider's connection
Ventilation services
Mechanical ventilation	Supply and extract ventilation to occupied spaces
Toilet extract ventilation	Extract from toilets and change areas
Air conditioning	A ventilation system that controls the temperature and humidity in a space. Air conditioning systems have many different forms, dual duct, constant volume, etc.
Fume extract ventilation	Removal of contaminated air from processes generating fumes, e.g. work inside fume cabinets
Local extract ventilation	Removal of contaminated air from small point sources, e.g. solvent laden air from a chemical process, sampling point
Dust extract ventilation	Removal of dust from process plant handling solids, e.g. bagging of powders
Natural ventilation	Ventilation of spaces utilising naturally occurring variations in pressure caused by temperature and wind
Kitchen extract Clean area ventilation and pres...

Table of contents

• Cover
• Half Title
• Full Title
• Copyright
• Contents
• List of figures
• List of tables
• Acknowledgements
• Abbreviations
• Preface
• 1 Introduction
• 2 The building services designer's role and responsibilities
• 3 Design in engineering construction
• 4 Feasibility studies
• 5 Concept design stage
• 6 The design brief
• 7 Scheme design stage
• 8 Detail design stage
• 9 Construction design information
• 10 Construction
• 11 Design feedback
• Index