Construction Waste Minimisation Design in China:中国建筑垃圾最小化设计 :

through a Comparative study between the UK and China

Yi Ying HAO, Jian KangSchool of Architecture, University of Sheffield

Introduction The UK and China are both confronted with an in

creasing rate of construction （建设速度） and a decreasing capacity of landfill （填埋能力） at present, which calls for construction waste minimisation urgently.

Considerable differences have been found in the effort on waste minimisation （垃圾最小化） as well as on construction waste minimisation design （建筑垃圾最小化设计） between the UK and China.

A comparative study was made based on the existing survey in the UK. The survey in China includes:

Acquaintance of the legislations ( 对法律的熟悉程度 ) Implementation of construction waste minimisation design ( 建

筑垃圾最小化设计实施 ) Causes of construction waste ( 建筑垃圾产生原因 ) Barriers & incentives for construction waste minimisation desi

gn ( 建筑垃圾最小化设计的障碍和鼓励措施 ) Architects’ attitudes to construction waste ( 建筑师对建筑垃圾

的态度 )

Source: http://photos.nphoto.net/photos/2007-09/06/ff80808114c5908e0114d6acb3cd5432.shtml

Introduction

UK China

Construction waste(建筑垃圾 )

120 million t of construction, demolition and excavation waste is produced by construction industry per annum.More than 25 million t of construction waste is disposed by landfill in the UK every year.

By 2020, China will increase 30 billion m2 of construction area, so the amount of potential construction waste will be an amazing number (1500-1800 million t).

Need for reclaimed and recycled materials (对回收再利用的材料的需求 )

(1)Minimisation of wastes during aggregates production(2)Careful use of aggregates in the process of construction,(3)Appropriate use of aggregates (4)Increased substitution of secondary and recycled materials for primary aggregates.

Green Construction Guideline (2007) (绿色施工导则 )encourages the development of new technology, new equipment and new materials in green construction, including the application technology of reclamation of the construction waste in envelop materials.

Information sources for construction waste minimisation design (建筑垃圾最小化设计的信息来源 )

Legislations on waste disposalHandbooks on construction waste minimizationWebsite, competition, training course for waste minimization design

Legislations on waste disposalInformation of material recyclinglittle information supports online

Models for construction waste evaluation (建筑垃圾评估模型 )

BREEAM, SPeAR, LCA In 2007, Green Building Assessment (绿色建筑评估 ) the first book in China systematically is published introducing the U.S. LEED, U.K. BREEAM, Japan CASBEE, GreenCalc+, Taiwan Green Building, Australian NABERS.

Role of construction waste minimisation design (建筑垃圾最小化设计的作用 )

Design for Reuse and Recovery;Design for Off Site Construction;Design for Materials Optimisation;Design for Waste Efficient Procurement; andDesign for Deconstruction and Flexibility.

when it comes to construction waste minimisation, waste management and technology supports seem to be emphasized most frequently. The views on designing out waste are limited.

Method Respondents

The architects in Grade A Architecture Design Institutes in provincial capitals ( 省会城市的甲级设计院 )

The ranking of these institutions in China is mainly based on the registered capital, the scale of projects and

the number of registered architects. Questions

The questionnaire totally includes 20 questions, with seven same questions as those of the survey in the UK.

Single-choice questions, multiple-choice questions, rating scales and open questions in the questionnaire. Questionnaire distribution and return

The use of questionnaire web page

The address of the web page was sent to 80 architects, with the response rate of 76%. Data Analysis

Statistical Package for Social Science (SPSS)

Approaches of analyzing:

One Sampling t-Test (comparing means)

Independent samples t- Test (compare variables

between two group)

Tabulated open-ended questions (collect and

analyze individual suggestions)

0

5

10

15

20

25

30

Bei J i ng ShangHai Ni ngBo GuangZhou ShenYang UnknowProvi nci al capi tal s

Reso

pons

es

Method

Working age

（工作年限）

Education level

（教育程度）

Workload

（工作量）

0

5

10

15

20

25

30

(0)0-1 year (1)2-5 years (2)more than 5 yearsWorki ng age

Quan

titi

es

0

5

10

15

20

25

30

35

40

Lower thanBachel or

Bachel or Master

Educat i on qual i fi cat i on

Quantity

05

1015202530354045

Very heavy Heavy Medi um Li ght Very l i ght

Work l oad

Resp

onse

s (%

)

Questionnaire Sample

RESULTS: Chinese architects

Acquaintance with relevant legislations ( 对相关法律的了解程度 )

The respondents do not know the legislations.

< PRC Law of Solid Waste Pollution Prevention and Control > 《中华人民共和国固体废物污染环境防治法》 34.4%

< Law of Urban Solid Waste Disposal > 《城市固体垃圾处理法 》 37.7%

<Green Construction Guideline> 《绿色施工导则》 39%

<Urban Construction Waste Management Regulations> 《城市建筑垃圾管理规定》 37.7%

Acquaintances of the concept of construction waste minimisation design ( 对建筑垃圾最小化设计概念的了解程度 )

Over 60% of respondents reported that they never heard the concept of constr

uction waste minimisation by design, therefore, most of them have not had a

clear and scientific idea on what is construction waste minimisation by design.

Courses and projects relevant to construction waste minimisation design in college ( 大学里和建筑垃圾最小化相关的课程和设计 )

More than 85% said that they never attended any courses on designing out wa

ste. Meanwhile, nearly 80% acknowledged that they never did the projects wh

ich were concerned with construction waste minimisation design in college.

0 10 20 30 40 50 60 70

Never

A l i tt l e

Medi um

Of ten

Very Of ten

Responses (%)

0102030405060708090

100

A great many Many Medi um A few None

Resp

onse

s (%

)

Courses Proj ects

Background Information

Green Housing Rating Systems

Usage of Green Housi ng Rati ng Systems

0 10 20 30 40 50 60 70

Never

A l i tt l e

Medi um

Of ten

Very Of ten

Responses (%)

The usage of Green Housing Rating Systems ( 绿色建筑评估系统 ) can reflect the Chinese architects’ concern with sustainable design and construction waste minimisation.

Never over 60%

A little nearly 20%

Often 6.6%.

Employ Green Housing Rating Systems in projects

0

0. 2

0. 4

0. 6

0. 8

1

1. 2

1. 4

1. 6

1. 8

2

(0)0- 1 year (1)2- 5 years (2)more than 5years

Worki ng age

Mean rating

1. 45

1. 5

1. 55

1. 6

1. 65

1. 7

(0) Bachel or (1) MasterEducati on

Mean

Rat

ing

1. 44

1. 46

1. 48

1. 5

1. 52

1. 54

1. 56

1. 58

1. 6

1. 62

(0)Medi um (1)Very heavy

Workl oad

Mean

Rat

ing

RESULTS: Chinese architects

Importance of construction waste mi

nimisation design

Very important over 35%

Extremely important about 22%

Not important at all 0%

I mportance of constructi on waste mi ni mi zati on desi gn

0

510

15

20

2530

35

40

Extremel y Very Moderatel y Sl i ght l y Not at al l

Resp

onse

s (%

)

Most of the Chinese architects acknowledge the importance of designing out waste. 3. 4

3. 5

3. 6

3. 7

3. 8

3. 9

4

4. 1

(0)0-1 year (1)2-5 years (2)more than 5years

Worki ng age

Mean rating

3. 4

3. 45

3. 5

3. 55

3. 6

3. 65

3. 7

3. 75

3. 8

(1)Bachel or (2)Master

Educati on

Mean

rat

ing

3. 68

3. 7

3. 72

3. 74

3. 76

3. 78

3. 8

3. 82

(0)Medi um (1)Very heavy

Workl oad

Mean rating

RESULTS: Chinese architects

Views on the importance of construction w

aste minimisation design ‘extremely important’ and ‘very important’(1) Beneficial to saving sources ( 资源 )and energy ( 能源 )(2) Reducing waste ( 垃圾 )and pollution ( 污染 )and protecting

environment. (3) Considered as a challenge ( 挑战 )as well as a responsibilit

y ( 责任 ) (4) The problem of waste would be more serious in the forese

eable future ‘moderately important’ (1) The current economic and management level ( 经济和管理

水平 )could not support it. (2) No requirement from clients ( 甲方 )and legislation( 法律 ), (3) Little knowledge ( 了解 )of it (4) A lack of design time ( 设计时间 ). ‘slightly important’(1) Mainly produced during the process of construction( 建造

过程 ), and not related to design strategies( 设计策略 )(2) Inevitable due to big design changes(3) Considered as a stunt ( 噱头 )(4) Complicated and difficult to put into practice, while less be

nefit(5)The public have not pay attention to it. ( 公众不重视 )

“ 尽管好多建成建筑，会因为设计不当，施工不当等等出现很多问题，但只要是满足审核，不影响销售，都会原封不动的接受。”

“ 说实话，觉得设计改动巨大，导致最后错误的信息巨多，无可避免。”

RESULTS: Chinese architects

“ 当建筑接近环境的承载量，建筑垃圾和环境之间的关系会变的极其敏感，所以在大量问题没出现之前，研究和用于实践，避免严重后果的出现时十分重要的。”

Information sources for waste minimisation

More than 50% of information of waste minimisation came from media and articles ( 媒体 / 文章 ), but the information support from training courses ( 培训课程 ) and professional bodies was very limited, each occupying 3.3%.

The architects in the UK had more information channels, including professional bodies ( 专业团体 ), personal research ( 个人研究 ).

The fact that the information sources are relatively inadequate （不足的） can reflect the current situation that the consciousness of the importance of information for designing out waste （垃圾最小化设计信息的重要性） is still not enough in the whole society of China.

RESULTS: comparison between the UK and China: what is the problem?

0 10 20 30 40 50 60

Medi a/ art i cl es

Personal research

Professi onalbodi es

Trai ni ng courses

Other

Wast

e mi

nimi

sati

on s

ourc

es o

fin

form

atio

n

Responses(%)

0 10 20 30 40 50 60

Medi a/ art i cl es

Personal research

Professi onalbodi es

Trai ni ng courses

Other

Wast

e mi

nisa

tion

sou

rces

of

info

rmat

ion

Responses (%)

UK (Source: Osmani & Glass, 2007)China

Waste minimisation design barriers

‘Lack of interest from clients’ ( 甲方缺少兴趣 )is also the top significant waste mini

misation barrier in China, followed by ‘poorly defined individual responsibility’ ( 不明确的个人职责 )and ‘lack of training’( 缺少培训 ).

(b) China

Barriers (China)Responses

Mean rating

Ranking

Lack of interest from clients 4.12 1

Poorly defined individual responsibilities 3.76 2

Lack of training 3.75 3

Waste accepted as inevitable 3.59 4

1. Not a barrier; 2. Insignificant barrier; 3. Minor barrier; 4. Significant barrier; 5. Major barrier.

(a) UK (Source: Osmani & Glass, 2007)

Barriers (UK)Responses

Mean rating

Ranking

Lack of interest from clients 3.88 1

Waste accepted as inevitable 3.83 2

Poorly defined individual responsibilities 3.80 3

Lack of training 3.70 4

Cl i nents' requi rement for waste mi ni mi zati on desi gn

0 10 20 30 40 50 60 70 80

Never

A l i tt l e

Medi um

Of ten

Very Of ten

Responses (%)

Nearly 70% said that clients never called for waste minimisation design, while only 3.3% declared clients often asked for it.

RESULTS: comparison between the UK and China: what is the problem?

Causes of construction waste Design stages

Site operations

0

1

2

3

4

5

Last mi nutechanges due to

cl i ent ’ srequi rements

Desi gn changes Del ays due todrawi ng

revi si on anddi st r i but i on

Detai l i ngerrors

Lack ofi nf ormat i on on

drawi ngs

Uncl earspeci fi cat i on

Causes of constructi on waste duri ng desi gn stages

Mean

rat

ing

Chi na the UK

0

1

2

3

4

5

off -cuts f romcutti ng materi al s

unused materi al sand products

waste f romappl i cati onprocesses

i mproper stori ngspace and methods

del ays i nforwardi ng

i nformati on onsi zes of

materi al s to beused

weathercondi t i ons

Causes of constructi on waste duri ng si te operati ons

Mean

rat

ing

Chi na the UK

Last minute change due to the clients’ requirement

( 甲方要求导致的最后的改动 ) 4.15Design changes

( 设计改动 ) 3.93 Detailing errors

( 细节错误 ) 3.66

The difference between these mean ratings of the listed causes is slight. The mean ratings a

re relatively high.

Off-cut from cutting materials ( 切割材料带来的下脚料 ) 4.31Unused materials and products ( 未使用的材料和产品 ) 4.28 waste from application processes ( 实施过程中产生的垃圾 ) 4.10

The mean ratings of each cause of waste during site operations are relatively higher than that during design stages, the same as the results fr

om the architects in the UK.

RESULTS: comparison between the UK and China: what is the problem?

Waste minimisation design incentives

Chinese architects also believed legislation ( 法律法规 ) was the key waste minimisation incentiv

e, followed by financial rewards, while training ( 培训 ) was the least significant measure.

An allowance ( 补助 ) for recycled construction products ( 再生建筑产品 ),

Tax credit ( 抵免所得税 ) for the construction companies use recycled products ( 使用再生产品 ),

a higher tax ( 较高税收 ) on the construction companies use original products ( 使用原始产品 ) to

encourage reducing( 减少 ), reusing ( 再利用 ) and recycling ( 循环使用 ) of waste materials.

China

Incentives (China) Responses

Mean rating

Ranking

Legislation 4.40 1

Financial rewards 4.30 2

Waste management policy in place 3.74 3

Training 3.35 4

1. Not an incentive; 2. Insignificant incentive; 3. Minor incentive; 4. Significant incentive; 5. Major incentive.

UK (Source: Osmani & Glass, 2007)

Incentives (UK)Responses

Mean rating

Ranking

Legislation 4.55 1

Financial rewards 4.55 1

Waste management policy in place 3.93 2

Training 3.90 3

RESULTS: comparison between the UK and China: what can we do?

Waste minimisation design strategies

Generally the waste minimisation design strategies are not very often used in projects in China. The difference between two countries are not significant.

F & D ( 垃圾测算可行性研究 )&( 可拆解设计 )strategies are the least popular in projects in China, which is the same as in the UK.

0

0. 5

1

1. 5

2

2. 5

3

3. 5

Feas

ibil

ity

stud

yof

was

te e

stim

atio

n

Desi

gnin

g fo

rde

cons

truc

tion

Use

of s

tand

ard

dime

nsio

ns a

ndun

its

Use

ofpr

efab

rica

ted

unit

s

Spec

ifyi

ngre

clai

med/

recy

cled

mate

rial

s

Use

of s

tand

ard

mate

rial

s to

avo

idCu

ttin

g

Avoi

danc

e of

lat

eva

riat

ions

in

desi

gn

Guid

ance

for

haza

rdou

s wa

ste

Mana

geme

nt

Waste mi ni zati on desi gn strategi es

Mean ra

ting

Chi na the UK

China

Waste minimisation design strategies (China)

Architects responses

Percentage Mean rating Ranking

1 2 3 4 5

Feasibility study of waste estimation 50.8 27.9 11.5 9.8 0 1.80 8

Designing for deconstruction 36.1 27.9 27.9 8.2 0 2.08 7

Use of standard dimensions and units 14.8 13.1 36.1 26.2 9.8 3.03 1

Use of prefabricated units 16.4 19.7 39.3 19.7 4.9 2.77 4

Specifying reclaimed/recycled materials 16.4 42.6 26.2 11.5 3.3 2.43 5

Use of standard materials to avoid Cutting 14.8 16.4 39.3 21.3 8.2 2.92 2

Avoidance of late variations in design 19.7 19.7 31.2 23.0 6.6 2.78 3

Guidance for hazardous waste Management 32.8 32.8 18.0 11.5 4.9 2.23 6

1. Never been used; 2. Rarely used; 3. Used in some projects; 4. Used in most projects; 5. Used in all project.

RESULTS: comparison between the UK and China ： what can we do?

Waste minimisation design

‘Old building reconstruction’ ( 旧建筑改造 )is the most usual in practical projects, and it is considered as the most effective construction cost-saving method.

The ‘use of recycled materials’( 使用再生材料 ) is rarely put in practice ，

but it is considered as the second effective method.

design types(China) Responses

Mean rating Ranking

Old building reconstruction 2.50 1

Flexible design 2.10 2

Reclamation of construction materials 2.07 3

Use of recycled materials (e.g. recycled concrete & recycled bricks)

2.02 4

1. Never been used; 2.Rarely used ; 3.Used in some projects; 4.Used in most projects; 5.Used in all projects .

Design types(China) Responses

Mean rating Ranking

Old building reconstruction 3.37 1

Use of recycled materials (e.g. recycled concrete & recycled bricks)

3.29 2

Flexible design 3.20 3

Reclamation of construction materials 2.67 4

1. Not at all; 2.Slightly; 3.Moderately; 4.Very; 5.Extremely.

Cost-saving of construction waste minimisation design

Implementation of construction waste minimisation design

RESULTS: comparison between the UK and China ： what can we do?

Waste minimisation management means

In China, more than 60% of respondents acknowledged that they never did anything in waste minimisation management means. The respondents who never did anything for these responsibilities in China were twice ( 两倍 )that in the UK.

The architects in the UK have more means in construction waste minimisation.

0 10 20 30 40 50 60 70

None

Prepare a l i st of each waste mater i al t o besal vaged,

reused of recycl ed

Desi gnat i ng waste di sposal operators

Other

Anal ysi ng si te waste to be generated

Waste management goal set t i ng

I ssui ng gui del i nes f or waste segregat i on

Organi si ng waste management meet i ngs

Responses (%)

0 10 20 30 40 50 60 70

Waste management goal set t i ng

I ssui ng gui del i nes f or waste segregat i on

Prepare a l i st of each waste mater i al to besal vaged,

reused of recycl ed

None

Desi gnat i ng waste di sposal operators

Anal ysi ng si te waste to be generated

Organi si ng waste management meet i ngs

Wast

e mi

nimi

sati

onre

spon

sibi

liti

es

Responses(%)

RESULTS: comparison between the UK and China ： what can we do?

Conclusion

潜在大量建筑垃圾的隐患需要被认识到。

需要更多的信息来源，例如网站以及专业团体的信息支持。

建筑师，工程师，甲方以及建筑公司，建筑材料公司的合作。强调建筑师的作用。

作为建筑设计辅助工具的建筑垃圾评估模型需要研发。

材料清单和数据库需要完善，加入更多的再生材料，为建筑师提供更多创新机会。