Principles of element design

THIRD EDITION

PRINCIPLES OF

eeme

desian '

Peter Rich &

Wonne Dean

Principles of

Element

Design

O Routledge

Taylor & Francis C ro u p

LO N D O N A N D NEW Y O R K

Principles of

Element

Design

Third edition

Peter Rich and Yvonne Dean

Architectural Press

A r c h ite c tu r a l P re ss is an im p rin t o f R o u tle d g e

F irs t p u b lis h e d by B u tte rw o rth -H e ln e m a n n

2 Park Square, M ilton Park, A b in g d o n , O xfo rd sh ire 0 X 1 4 4 R N

71 1 T h ird A ve n u e, N ew Y o rk , N Y 1 0 0 1 7

Routledge is an im print o f the Taylor and Francis G roup, an in fo rm s business

First Issued In hardback 2 0 1 5

© Peter Rich and Yvonne Dean 1999

A ll rights reserved. No part of this publication may be

reproduced in any m aterial form (including photocopying

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A pplications for the copyright holder’s written perm ission

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British Library Cataloguing in P ublication Data

A catalogue record for this book is available from the British Library

ISBN 978-0-7506-3113-6 (pbk)

ISBN 978-1-138-13886-5 (hbk)

lib ra r y o f Congress Cataloguing in Publication Data

A catalogue record for this book is available from the Library of Congress

Com position by Scribe Design, Gillingham , Kent, UK

Contents

Introduction vii

Foreword viii

Preface to the Third Edition ix

Section 1 Foundations: General 1

Section 2 Foundations in Detail 9

Section 3 External Walls: General 19

Section 4 External Walls: Basic Types 30

Section 5 External Walls: Detailed Sections 44

Section 6 Floors: General 49

Section 7 Floors in Detail 58

Section 8 Roofs: General 76

Section 9 Flat Roofs: Basic Types 86

Section 10 Flat Roofs in Detail 95

Section 11 Pitched Roofs in Detail 103

Section 12 Internal Walls: General 115

Section 13 Internal Walls in Detail 124

Section 14 Stairways, Ramps, Handrails and Balustrades: General 129

Section 15 Stairways, Ramps, Handrails and Balustrades in Detail 144

Section 16 Windows: General 150

Section 17 Windows in Detail 155

Section 18 External Domestic Doors 161

Introduction

Although som e construction textbooks recognize the

need to state principles rather than m erely describe

solutions, they often ju m p from over-generalized

principles to specific solutions Because of the increas￾ing variety of m aterials, com ponents and aesthetic

aim s, textbook solutions tend to be short-lived. In

addition, fluctuating cost ratios between m aterials and

labour as w ell as deteriorating levels of site craftsm an￾ship m ean that textbook solutions can rarely be used

by the designer w ithout som e degree of adaptation

Not all the b u ild in g failu res of recent years can be

blam ed on designers, but too m any, certainly, can be

traced back to a point in the design stage at w hich an

outdated textbook or w ell-tried solution w as falsely

adapted to meet a new set of circum stances. To help

overcom e the hazards of adaptation from textbook to

draw ing board or from job to job, these reference

sheets are conceived as a sim p le checklist of principles.

Thus for each b u ild in g elem ent the sheets system ati￾cally list the range of factors likely to require consider￾ation. Most of the elem ents dealt w ith include at least

one exam ple in order to dem onstrate a typical current

solution to the problem s discussed. An additional aim

has been to inform the designer of the wealth of refer￾ence m aterial applicable to each elem ent. References

have been separated into textbooks. Statutory Regula￾tions, British Standards, B u ild in g Research Establish￾m ent Digests and Current Papers as w ell as good

practice guides issued by the various trade and research

organizations. No textbook or checklist can possibly

keep pace w ith the ever increasing body of recom￾m endations and m andatory regulations: however, it is

hoped that the initial listing of sources in this format

w ill m ake it easier for designers to update their refer￾ences as and when they are required.

Peter Rich

Building Regulations

The docum ents referred to in this book relate to the

Bu ild in g Regulations 1991, Am d 1994, Docum ents A -N ,

apart from Docum ent L (1995 edition).

See also Bu ild in g (Scotland) Act (1959), revised 1977.

British Standards and Codes of Practice

Many standards and codes of practice have been

am ended since their first issue. Up-to-date am endm ent

slips are supplied autom atically when docum ents are

purchased. Am endm ent slips m ay also be obtained

separately. However, users should check w hich am end￾ment is referred to in the Bu ild in g Regulations.

To confirm the latest am endm ent for any particular BSI

document, consult Update’ published m onthly by BSI.

BSI Standards

389 Chiswick High Road

London W4 4AL

Tel. 0181-996 9000

Fax 0181-996 7400

Customer Services - Tel. 0181-996 7000

Building Research Establishment

publications

A full list of current BRE publications including Digests,

Current Papers, Inform ation Papers and Reports is

given in the annual Construction Publications catalogue

obtainable from:

B uilding Research Establishment: Construction Research

Com m unications Ltd

B ucknalls Lane

Garston

Watford WD2 7JR

Tel. 01923-894040

Fax 01923-664010

Foreword

O lder architects som etim es lam ent what they see as a

decline in technical skill am ong their younger

colleagues. What they often neglect to m ention are the

big developments in product design, building

processes, environm ental awareness, not to m ention

CAD, that have transformed architectural practice in the

last two or three decades.

Com paring this edition of Principles o f Element Design

with its excellent predecessors (the comm on factor, of

course, is Peter Rich) I am totally confident that the

tradition of intelligent, scientifically based but practical

teaching of constructional skills in British architectural

schools has not been broken. This tradition In Its

thorough, unem phatic. open-ended, systemic way dates

back to the founding of the Bu ild in g Research Station

(near BRE) over sixty years ago. It Is a wonderful tradi￾tion. Quite evidently from the pages of this new edition,

the spirit of enquiring, non-dogm atic. practical em piri￾cism lives on.

And so does another tradition, equally precious. This

is the ongoing habit In British architectural publishing

of m eticulously assem bling references, technical data

and sources of inform ation, not just in dry lists, but

with direct reference to design tasks that have to be

addressed today. The am ount of inform ation, directly

related to design invention, that Yvonne Dean has

brought together in this new edition is astonishing,

both in scope and In conciseness.

Architectural design is more than the m indless

repetition of standard details. Nor is It m indless inven￾tion. It is the continuing programme, shared by ail

architects of developm ent, in the context of action, of

a body of experience intended to achieve the greatest

benefits for clients and users with the most elegant and

intelligent use of lim ited resources.

Principles o f Element Design is a most useful source

of technical inform ation. It is also an outstanding

manifestation of continuing professionalism.

Francis Duffy

Formerly President of the RIBA

Preface to the Third Edition

Since th is book was o rig in a lly pu blish ed as P rinciples

of Elem ent Design, there have been a n u m b er of

changes in how b u ild in g is organ ized and how the

very nature of b u ild in g is perceived. A lthough the

m aterial w as p ublished as a series of inform ation

sheets in the Architect's Jo u rn a l betw een 1974 and

1976. the contents reflected the period of the

1960s.There w ere very real d iffic u ltie s fac in g p racti￾tioners w ho had to cope w ith a sudden expansion of

new b u ild in g techniques and products and th is was

com parable to the change in b u ild in g cultu re that

took place in the 1930s. A reassessm ent of b u ild in gs

was carried out in this period and greater guidance

given to the b u ild in g industry. P u b lica tio n s such as

A Q u alita tive Study o f Som e B uilding s in the London

Area pu blish ed by the HMSO in 1963 reviewed some

w ell-know n b u ild in g s between 20 and 30 years old

and recognized that the tech n iq u es and m aterials

used w ere often experim ental. The o v e rrid in g co nclu ­

sion in this review showed th at o rigin a l specifications

had not been follow ed and w as often a cause of

failure.

S im ila rly the period of the 1960s and 1970s devel￾oped yet another quite different b u ild in g culture of

m aterials, assem bly and know ledge of production

techniques that often superseded this interw ar period

as well as traditional m ethods. However, new percep￾tions with regard to like ly failu re had highlighted

areas w here newly defined prin cip les on b u ild in g

m ovem ent and w eathertightness w ere now follow ed

and these becam e incorporated into revised Codes of

Practice and the B u ild in g Regulations. To their credit,

George Godw in published, in book form , the series of

articles that Peter Rich had com piled. These broke

dom estic architecture down into m anageable

elem ents with the o verriding prin cip les that should

inform th eir construction. C hecklists of the main

factors that affected each elem ent w ere published

w ith key diagram s.

By its very nature adopting a principle-based

approach im plies a certain tim eless application of

ideology to building, and yet principles do change and

certainly the priorities in the application of principles

shift. For exam ple, the first volum e of Principles of

Modern Building, published in 1938 by the HMSO and

then revised in 1959 with the publication of the second

volum e, stayed in print until the late 1960s. These

books, written by experts at the B uilding Research

Station, took the first step away from traditional

textbooks by their clear application of b u ild in g science

to construction and the functional aspects of different

elements. They also considered the building as a whole

d ealing with principles that im pinged on every elem ent

including;

Strength and stability

Dim ensional stability

Exclusion of water

Heat insulation

Ventilation

Sound insulation

Daylighting

Fire protection

Durability, com position and m aintenance

B uilding econom ics

Principles of use of m aterials

D ealing with architecture in an elem ental w ay is

also not new. Viollet-le-D uc categorized elem ents of

architecture in the first volum e (1854) of his

Encyclopédie Médiéval and these included in d ivid u al

structural elem ents such as arches, spatial elem ents

such as types of rooms, and elem ental types of a rch i￾tecture. ranging from houses to colom bier (house for

pigeons), and in d ivid u al parts such as balustrades.

However, the second volum e was entitled Architecture

and included m ob ilier - m eaning literally m ovable

possessions. A lthough the m eaning today generally

refers to furniture, the word then had a far w ider

m eaning and included all m ovable artefacts inclu ding

clothing. It is a reflection of how specialized we have

becom e that the area of interest in b u ild in g has

becom e so narrow. True com fort does include clo th ­

ing: the ability to live does necessitate storage of

possessions (whether 'm obile' or fixed) and storage in

b u ild in gs is an issue, but the totality of designing and

Preface to the Third Edition

b u ild in g for livin g is now shared between different

industries and as a result th eir integration is poor.

Current research is re-evaluating com fort conditions in

b u ild in g s and th is cannot be done w ithout allow ing

for clothing.

Princip les o f Elem ent Design by Peter Rich applied

d ifferent che cklists to each elem ent, listin g the m ain

factors that w ould im pinge on any elem ent. Although

the fun d am en tal preoccupations in b u ild in g, for

com fort and shelter, have not changed, som etim es

the m ain a im s for b u ild in g can becom e lost in the

plethora of discrete checklists. As specialism s

develop, m any elem ents w hich should be designed as

a to tally integrated b u ild in g system becom e too

abstracted

This third edition categorizes the elem ents in such a

way that their interdependence is considered.

What are the additional or rediscovered principles

that im pinge on how we m ight build today? Priorities

certainly change and become m ajor criteria in deter￾m in in g the perform ance of elem ents. Overriding

concerns deal w ith a concept of efficiency that relates

not just to the execution of a m anufacturing process or

arrangem ent of the b u ild in g process, but to the

m inim ization of the use of energy. In fact, the building

itself must demonstrate increasingly not merely a

com pliance with current regulations w ith regard to

therm al perform ance but an optim ization of the use of

energy given current knowledge.

The industry is also more client-led. There are

increasing concerns with m aintenance and quality and

the growth of facilities management, a recognition ol

the need for looking after buildings in the long-term

and being able to m aintain them with the m inim um of

physical labour or disruption.

The dissatisfaction with m odern architecture that

experim ented and failed in the application of m any

new m aterials and com ponents has also led to a shift

in responsibility. As the expectation of failure increases

and insurance becomes a key com ponent in the

successful financing of buildings, a claim s-consclous

industry starts to set its own standards. As ownership

and fun d in g changes, the basic quality and equity of a

b u ild in g is increasingly led by m ortgage societies who

apply their own standards to their own assets. This

factor alone has changed standards in building. As

large com m ercial organizations, they can respond

sw iftly to changing conditions. G uidelines from

m ortgage and insurance com panies to the use of NHBC

standards now give additional dem ands and

som etim es a restrictive fram ew ork around the practice

of building. The response to clim atic change and

identification of high risk areas where ground condi￾tions are poor, is reflected in dem ands on home

owners to pay add itio nal insurance and Im prove the

foundation structure of buildings where failure is likely

or has occurred.

The changes in the responsibilities for health and

safety have also delegated the m echanics for com pli￾ance back to professionals. This is no bad thing as self￾certification should be inherent in a professional

qualification instead of reliance on inspectors to

regulate com pliance. However, the burden of extra

adm inistration and the tim e involved in m anaging the

bu ild in g process does detract from the m ain rationale

for building and consequently advances become incre￾m ental in the application of new ideas. As the infor￾mation base becom es further fragm ented, there are

few overall guides to a holistic view of building. Even

the BRE now deal with more self-contained aspects of

construction and this fragm entation of knowledge is

reflected In highly specific areas of research. Criticism

of this approach is by no means new. In Barry Russell's

introduction to Building Systems, Industrialisation and

Architecture, published by Wiley in 1981, he quoted

Stafford Beer on the analytic method of scientific

enquiry.

We are not trained to think in systemic terms

because our scientific approach has been analytic to

the ultim ate degree. We took thmgs apart histori￾cally. and described the atomic bits. We d id an

experiment, historically on these bits deliberately

holding invariant the behaviour of other bits with

which in fact they were systematically interacting

real life.

Peter Rich added that Bill Allen (of Bickerdicke Allen

and Partners) also concluded that most building

failures were the result of the ‘unknown interactions

between the known elements'.

This phenom ena is by no m eans confined to

research. It is prevalent in higher education with the

division of subject areas into sm aller pieces of packaged

inform ation. Although a broader approach can be

found In textbooks, these have a long tim escale in their

production. Shelf life for books can be lim ited unless

the book itself can be proactive in determ ining issues

that w ill be relevant in the future as well as reviewing

and rem inding people of the basic issues that will

Preface to the Third Edition

alw ays im pinge on construction. For this reason the

approach in the third edition has been to speculate on

events that are likely to influence methods of b u ild in g.

There are some events that can be reasonably

predicted. The chm atic variations experienced in the

last 20 years led to a rationale to build for worst case

scenarios, instead of com pliance with legislation that

sets m inim um standards. Although there is still

disagreem ent in the scientific com m unity as to the

reasons for clim atic change and whether global

w arm ing is happening as predicted, there is evidence

that change is occurring and the steady increase of CO^

em issions is harm ful and must be controlled.

As the dem and for m aterials becomes m ore acute

this is reflected in more lim ited choices. For exam ple,

the dem and for softwood has resulted in the use of

taster grow ing and inherently w eaker tim ber that sets

lower lim its of perlorm ance.

As the b u ild in g stock has increased, the application

of b u ild in g technology is inevitably concerned with the

renewal of existing housing stock. Buildings also have

to respond to shifts in use that are more profound and

can allow for change: the easy stripping out of services

and renewal of the fabric generally at the sam e tim e as

m in im izin g waste. To build for specific use is no longer

reasonable. Currently the conversion of 1960s and

1970s office buildings to housing is a m ajor exam ple of

this change.

The prediction of trends in the long-term now takes

on greater significance. The dem ographic changes of an

ageing population flattening out to a steady state, the

increase of an older and yet m ore fragile population

brings its own constraints. Urban conglom erates are

also increasing but the services for these becom e m ore

cum bersom e and there is a definite shift towards

sustainability w hich w ill affect the storage of water, and

other inbuilt facilities for sorting household waste to

reduce the collection of rubbish. All of these issues

relate even more to the conversion of existing housing

stock w here the workload w ill be greater rather than

with or in new buildings. The sorting of b u ild in g

m aterials is also im portant as a valuable recycling

resource, and to some extent eco-labelling deals w ith

the life cycle of b u ild in g products as well as their origin

and processing.

Health issues also im pinge on the construction of

buildings. The rem oval of chim neys has resulted in poor

ventilation and alternative m ethods of introducing fresh

air to buildings. These have had to be rethought with

filtration m echanism s to counteract high levels of pollu￾tion. especially in cities. The indoor surface environm ent

is also poor and some current research im plies that the

removal of carpets to m inim ize infestation by house

mites is im portant to relieve asthm atic conditions. This

directly affects one m ajor elem ent of construction which

may not be able to rely on sim ple slab systems that are

not easily covered with m ore natural floorings. The

concern with energy efficient construction w ill also

combat condensation problem s by evening out therm al

differentials in the building shell.

The world econom ic clim ate can affect attitudes

towards building. In the period of fast growth in the

1980s, fast turnovers in the property field were not

conducive to b u ild in g for long-term returns. A flatter

growth curve encourages longer-term investm ent and a

more careful review of b u ild in g quality.

Today’s list of principles varies som ewhat from the

1959 list in Principles o f Modern Building by stating the

function of the p rinciple m ore clearly and the reflec￾tion of current concerns, especially in response to

energy usage and clim atic change. A new list w ould

include;

Structural stability

W eatherproofing

Construction for zero energy dem and

Design for healthy a ir infiltration and high internal air

quality

Use of external features, buildings, landscape for

shading

Comfort levels to be achieved all year round

D aylighting for solar energy gain and health

Sustainable a sp e a s of design, recyclable

Fire prevention/incom bustible elem ents/protection￾controlled fire spread/fire loading

Fire prevention and w arning systems

Fully accessible buildings

Secure buildings

Materials and construction choice to m in im ize energy

usage in production and delivery

Preface to the Third Edition

Principles o f Modern Building 1959

Strength and stability

Dim ensional stability

Exclusion of water

Heat insulation

Ventilation

Sound insulation

Daylighting

Fire protection

Durability, composition and m aintenance

Build in g econom ics

Principles of use of m aterials

Principles applied to building 7997

Structural stability

W eatherproofing

Construction for zero energy demand

Design for healthy dir infiltration and high internal air

quality

Use of external features, buildings, landscape for shading

Comfort levels to be achieved all year round

Daylighting for solar energy gain and health

Sustainable aspects of design, recyclable

Fire prevention/incom bustible elements/protection￾controlled fire spread/fire loading

fire prevention and w arning systems

Fully accessible buildings

Secure buildings

M aterials and construction choice to m inim ize energy

usage in production and delivery

Principles, by their nature, should be applied to exist￾ing as well as new buildings and, because additional

principles and new priorities have been so significant,

the conversion of existing housing stock has to be

radical to meet the above demands. The inheritance of

a fast-built Victorian housing stock also means a neces￾sary review of the real inadequacies of those buildings.

The elem ents explored in this book and their related

principles still apply in housing renewal. Even in new

buildings the exam ination of these sam e elem ents is

still relevant given the great changes in m aterials and

techniques in the twentieth century, as ‘at the same

tim e m any ways of b u ild in g types of houses are struc￾turally unchanged since the end of the last century’

(Brian Montgomery in the Introduction to Interbuild,

1995, Montgomery Exhibitions Ltd).

This country o f ours is fast becoming one great

waste o f badly formed, poorly designed and

unhealthy houses sim ply because the architect has

no force o f mind, no feeling fo r his position, no self

respect, no belief in his great purpose a nd no powers

of p u b lic control.

Raym ond McGrath 1935

One of the biggest problem s in learning about and

practising construction is information retrieval. It Is a

common problem for every profession that information

used has to be current. National and European standards

mean that part of the work in construction is m aking

sure that the specification of materials and organization

of the construction process com plies with various legis￾lation. Most legislation is a means by which the best ways

of gaining knowledge, gathered through experience and

research, are available to everybody. For the student or

practitioner the knowledge base is continually changing

and has also become a commodity. The most useful

access to a distillation of knowledge available is still

through textbooks and compendia and also direct infor￾mation on products from manufacturers. However, even

after som e fam iliarity is gained inform ation needs to be

checked to make sure it is still relevant. A sim ple way of

doing this is to obtain the latest BRE catalogue for their

publications on all aspects of building, and trade associ￾ations also have their own guidance sheets and books.

The British Standards Institute publishes a catalogue

every year which lists British and European Standards

and Codes of Practice. A valuable commercial tool avail￾able for offices Is the Barbour Microfile, now on CD-ROM.

which contains the largest library of information, ranging

from all Standards, Codes of Practice. BRE Digests and

other relevant publications as well as product informa￾tion. In this book relevant and up-to-date information

and Standards {to October 1997) is given fairly extensively

for each element.

In retrieving information it is rare to find parts of a

building catalogued as elements apart from slabs, doors,

windows or foundations. Generally, a decision would

have to be made as to what an individual element

would be made of, for exam ple whether constructed in

Preface to the Third Edition

steel, tim ber or masonry, and then in the Code of

Practice for that material you would find design advice

for colum ns or beam s or w alling systems. Co-ordinated

project inform ation is a system that categorizes drawn

and specification inform ation som etim es referred to as

part of a common arrangement. This system, w hich does

list the elem ents and m aterials in building, is also used

by British Standards to cross-reference back to relevant

m aterials. It is used in the m easurement of building

works, called the Standard Method of Measurement

which is abbreviated to SMM7. Conceptually the SMM7

system and the comm on arrangem ent is activity-based

and then arranged in a sequence that mirrors the

process of building. This does have differences in how

the total b u ild in g can be visualized by designers, where

it is im portant that the whole is realized or understood

first. The SMM7 categorization is listed at the beginning

of each section and w ill be useful to quantity surveyors

lin king their knowledge of categorization to building

principles for each element. SMM7 relates directly to the

system of classification for the National B u ild in g Speci￾fication (NBS).

The original book also ensured that all advice given

was set within the framework of the B uilding Regulations

and this edition is in the sam e spirit. The different

docum ents of the Regulations also present a set of areas

of interest that are generally relevant to all elements. All

parts of a building, whether controlling structural stabil￾ity. fire safety, ventilation, conservation of fuel and

power or resistance to sound, moisture or full accessi￾bility, m ust fulfil these basic criteria to be successful.

There is still a danger that the categorization by any

system into a checklist of concerns, whether in terms of

elem ents or principles, can m ake the original purpose of

a b u ild in g elusive. A b u ild in g has to provide comfortable

shelter, without hazard and provide an alternative

environm ent to the outside which is health-prom oting

and enables a range of activities to take place. On top of

these basic needs it m ust be robust and low in its energy

needs. Alm ost inevitably most of these basic concerns

will be com prom ised by cost and location and for any

designer w anting to im plem ent a thoughtful agenda the

going w ill be tough.

U ltim ately b reakin g a b u ilding into identifiable

elem ents is useful because it reveals the sim ple hierar￾chy of parts that go to m ake a b u ild in g and so demys￾tifies the com plexity of the w hole. This book is useful

for all professions and trades in the b u ild in g industry.