essay- why hk needs to rehabilitate to become sustainable (with illustrations)

7/30/2019 Essay- Why HK Needs to Rehabilitate to Become Sustainable (With Illustrations)

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Lecturer: Michael Robinson

Date: 6/6/2012

Student Name: Anne Cochin

Why Hong Kong Needs To

Rehabilitate Its Existing Buildings

To Design A Sustainable Future?

Hennessy Road, Hong Kong Island, 2012 (photograph: Anne Cochin)


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Abstract

Purpose

Considering the issues that HK is facing: population, scarcity of land, aging housing stock

and pollution- it can be interesting to examine if new construction is really a good option for

the city. For this purpose a definition of the sustainable city needs to be given, with three

different angles: urban landscape organization with a mixed used of buildings (for less

transportation) different heights of buildings, green spaces and water pools. On the

construction methods point of view the indoor air quality needs to be insured by ventilation

and use of low VOC* materials whereas energy efficiency is essential for low carbon

footprint. Lastly, time issues such as 'building to last', pride of one's heritage and culture

and economic growth will be explained

Findings

How far we are from the ideal city and wrong way to go was determined: urban decay is

examined with its consequences as health hazard and accidents, self image degradation

and loss of market value.

Demolition problems are stated, as waste treatment, energy need to crush waste,

impossibility of land use during works, nuisance (noise / dust...). Lastly, it is shown how

new developments are the current trend to redevelop rather than rehabilitate but the

rightness of this choice is far from obvious: questions are raised about the use of new land

(less nature), need for new infrastructures, high rises issues (energy efficiency / blocking

winds / social), construction footprint ( concrete / excavation for foundations / etc...) and

overall how the market enters a vicious circle.

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Then a strategy is developed: At the apartment level, about how the layout is to be

improved for modern way of living, with good care of indoor air quality (ventilation rather

than AC), windows, insulation and how materials need to be sourced locally. At the building

level, rejuvenating residential buildings as important as historical landmarks, addressing

maintenance issues (rather than wait for emergencies) is also required, and green roofs

are proposed as well as a facade scheme. At district level, solutions are proposed to re-

vitalize the urban fabric: creation of more green spaces, pedestrian zones, traffic control

and keeping environment to human scale. This will attract new high-income tenants or

companies. Lastly, shores also have to be especially preserved.

On a more spiritual level, the research finds how appreciation of heritage and local culture

of Hong Kong as a multi-layer environment can revitalize people and business and

impacts behaviors and how a plan for an informal city allows for more confident future.

Conclusions

Two major misconceptions are here proven wrong: firstly that Eco-friendly investments and

economic growth oppose each other and, secondly, that older buildings are worthless,

belief especially strong in Hong Kong. It is shown that, oppositely, green retrofitting is

rather a condition to future economic vitality in Hong Kong.

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Table Of Contents

Abstract...................................................................................................................................i

Purpose...............................................................................................................................iFindings...............................................................................................................................iConclusions........................................................................................................................ii

Table of Contents...................................................................................................................iii

List of Illustrations..................................................................................................................iv

Introduction.............................................................................................................................1Background:.......................................................................................................................1

Objectives..........................................................................................................................2Scopes and Limitations......................................................................................................2

Methodology...........................................................................................................................2

I/ Sustainable City: Definition.................................................................................................2A/ Urban landscape organization......................................................................................2B/ Design and Construction methods................................................................................4C/ Time consideration........................................................................................................5

II/ How far we are or The wrong way to go............................................................................5

A/ Urban decay..................................................................................................................5B/ Demolition......................................................................................................................6C/ New developments........................................................................................................7

III/ Recommended Strategy...................................................................................................8A/ Apartment level..............................................................................................................8B/ Building level.................................................................................................................9C/ District level.................................................................................................................10D/ Spiritual level...............................................................................................................11

Conclusion............................................................................................................................12

List of References................................................................................................................14Books...............................................................................................................................14Research Papers.............................................................................................................14Periodicals.......................................................................................................................14Web References..............................................................................................................15

Bibliography..........................................................................................................................16

Glossary...............................................................................................................................17

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List Of Illustrations

Figure 1: Smog in Hong Kong (Personal Photograph) 1

Figure 2: Building Heights Impact (source Hong Kong Planning Department, viewed 31May 2012 3

Figure 3: Greenhouse gases emission by Sectors (source Hong Kong EnvironmentProtection Agency, viewed 1 June 2012,)

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Figure 4: Electricity Consumption by Sectors (source Hong Kong Environment Protection

Agency, viewed 1 June 2012,)

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Figure 5: Decaying Buildings in Hong Kong (Personal Photograph) 6

Figure 6: New Developments in Hong Kong (Personal Photograph) 7

Figure 7: Example of Naturally ventilated Building (source Eco Building 101 Blog,) 9

Figure 8: Green wall at ICON Hotel (Personal Photograph) 10

Figure 9: Renovated Tong Lau in Hong Kong (Personal Photograph) 12

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Introduction

Background:

Hong Kong is a city with unique features: 7 million people on only 1,000 square kilometers

(HK in figures 2012, pp 9-10) and a complex history of many buildings layers: local ethnic

dwellings, colonial heritage, post-war construction under the pressure of Mainland

immigration waves, and, more recently, international high tech achievements...Now, if the

population growth has leveled off (only .7% in recent years, ibid.), the city is nonetheless

facing challenges in its urban planning choices: over speculation and a growing concern

about pollution.

Figure 1: Smog in Hong Kong (Personal Photograph)

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Objectives

Going one step ahead of recycle and re-use, let us see how rehabilitation is a better

choice for Hong Kong to build a sustainable future and therefore why the current trend of

always redeveloping has to stop. During this examination, Eco-friendly investments will not

be opposed to economic growth but, on the contrary, be shown as a factor of

development.

Scopes And Limitations

Hong Kong climate and cultural specificity will be examined and personal opinions will be

expressed but neither the political aspect of the question nor government decisions will be

commented. Besides, technical details of green construction will not be described.

Methodology

The report was carried out from secondary research, reading from a selection of books

and periodical stories as well as official websites accessed between May 10 th and June 5th,

2012. Conclusions come also from personal observation and reasoning.

I/ Sustainable City: Definition

'Sustainable' is a word that is used a lot (too much probably) nowadays but which can

cover different meanings, let us first define what a sustainable city should be.

A/ Urban Landscape Organization

In a sustainable city, each district has a mixed use of buildings. It allows inhabitants to

live, work, shop and even enjoy leisure time without resorting to transportation, which is a

major source of greenhouse gas* emissions (17% of emissions, source: HKSAR

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Environmental Protection Department). The lively atmosphere of a neighborhood with

diverse activities only reflects its environmental efficiency.

Because different buildings have different use, they have different heights and shapes. It

is important because the winds can circulate and ventilate the streets along with the

dwellings, allowing cooling as well as sweeping pollution particles.

Figure 2: Building Heights Impact (source Hong Kong Planning Department, viewed 31 May 2012

Green spaces are essentials to a better quality environment: not only can people enjoy

the sight of vegetation, and let their children play, but trees and plants absorb CO2 and

contribute to a better air quality, some plants can even clean the air from harmful particles.

Moreover, if those spaces are large enough, the water retained in their roots also has

cooling effects.

Waterpools, especially flowing water, do not have solely decorative purposes, they are

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actually a plus in terms of heat reduction in an urban context. That might be why Feng

Shui grant a great importance to them.

B/ Design And Construction Methods

One very important health issue that city dwellers face is respiratory diseases: according

to Hong Kong based independent think-tank Civic Exchange (press release dated 17

January 12012), the average annual deaths attributable to air pollution is 3,200. Good

ventilation along with the use of low VOC* materials is therefore essential. Ventilation

also insure better comfort during hot periods as well as humid periods.

To minimize the impact of human activity on our planet and limit climate change, we need

to lower our carbon footprint. Knowing that, in Hong Kong, buildings account for nearly

90% of electricity usage, all the range of energy efficiency strategies have to be

implemented: insulation, ventilation, daylight maximization, solar panels etc...

Figure 3: Greenhouse gases emission by Sectors (source Hong Kong Environment Protection Agency,viewed 1 June 2012, )

Figure 4: Electricity Consumption by Sectors (source Hong Kong Environment Protection Agency, viewed 1June 2012, )

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C/ Time Consideration

It seems only common sense to say that sustainable means build to last, indeed

sustainable means well-grounded, endurable and that includes a time dimension:

sustainable for a short period would be a paradox...

Thinking about the future immediately calls for historical considerations, as plants grow

from having good roots, a sustainable city must encompass a pride of one's heritage and

culture.

Lastly, Eco-friendly investments are too often opposed to business profitability but,

contrarily to popular thoughts, better environment means better conditions for economic

growth, especially when competing with other world cities in the region to attract foreign

investors.

II/ How Far We Are Or The Wrong Way To Go

A/ Urban Decay

According to the very official Urban Renewal Authority, there are around 4,000 buildings

aged more than 50 years old in Hong Kong and other sources mention 950 hectares of

obsolete housing. Many of those have been built quickly under the pressure of

immigration waves from Mainland and the lack of buildings with historical value in Hong

Kong leads to insufficient maintenance and therefore of general deterioration of older

housing stock.

In such dwellings, accidents increase from fires, poor electricity security, lift failures, illegal

apartments subdivisions, temporary structures etc.. Health hazards also occur from lead,

asbestos, undrinkable water and other hygiene issues.

The degradation of the dwellers self image does not encourage Eco responsible

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behaviors, and waste sorting, recycling or water conservation rules do not apply.

Figure 5: Decaying Buildings in Hong Kong (Personal Photograph)

Finally, decaying buildings lose their market value and consequently are vulnerable to

pressure of redevelopment. In a place where over emphasis has been placed on land

scarcity, real estate speculation is very strong.

B/ Demolition

Demolition itself needs energy (to knock down walls and crush waste), it also imply

transportation and waste treatment which consume energy and release greenhouse

gases* and diverse potentially harmful particles into the atmosphere.

When redeveloping, land cannot be used for works duration: this process can take up to

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5 years between the eviction of people till the completion of new construction.

Moreover, during this period, nuisances as noise and dust are inevitable whereas well

planned retrofitting can be gradual and allow inhabitants to stay on the spot.

C/ New Developments

Despite the many commercial and environmental advantages of retrofitting, the current

trend is still to redevelop rather than rehabilitate, One major obstacle we often find we

encounter especially here in Hong Kong, is the widespread perception that new is better

says Dr. Vincent Cheng, Head of Building Sustainability for Arup in Hong Kong.

So what are these disadvantages? Firstly, new developments need new land which

means less land left to nature (wild or cultivated) and lead to urban heat island effect*.

Secondly, construction carbon footprint is high, from concrete making, excavation for

foundations and other needs of transportation, machines engines while retrofitting

conserves the energy embodied within the structure.

Thirdly, new suburban towns need new infrastructures, which construction is again

damageable to environment.

Figure 6: New Developments in Hong Kong (Personal Photograph)

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Besides, new developments are mostly high rises which have their own issues in terms of

energy efficiency: there are conceived with high needs for air conditioning (windows are

often blocked for safely), lift operation, etc... Their shape make them block winds that

could ease the city hot and humid climate. As of social issues, Hong Kong seems to be

rather clear of them for now but other countries have observed correlation between high

rises and loss of human scale leading to violence and the risks can not be completely

ignored.

Lastly, building knowing that new construction will soon replace this one makes the market

enters the vicious circle of repeated cheap building redevelopments.

III/ Recommended Strategy

As new developments typically represent a maximum 2% of total housing stock, if some

green projects attract much attention, the impact on environment stays limited, the rest of

them, as seen above, presenting serious environmental problems. On the other hand,

letting older districts decay is not an option there is no choice but retrofitting them.

A/ Apartment Level

When retrofitting apartments, the layout must be adapted to a modern way of living,

which implies removing partitions and letting more day light in, improving fitted cabinets

and modern kitchen appliances. New bathroom fittings will have water preservation

features. To improve indoor air quality, the design will make sure that ventilation is

insured so air conditioning will be used as little as possible.

Windows are critical and must be double-glazed*, have studied orientation, and without

thermal leak- overall insulation beside needs to be improved. Please note that, besides

reducing electricity use, some studies show that a lighting upgrade in office buildings

brings an significant improvement in employees' productivity.

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Figure 7: Example of Naturally ventilated Building (source Eco Building 101 Blog,)

Materials must also be chosen to release as little VOC* as possible and will be sourced

locally to limit transportation, when possible they can even be reclaimed or recycled.

B/ Building Level

Recently an effort has been made to convert historical landmarks but it is essential to

rejuvenate residential buildings as well, they are the core of people's life and should not

be overlooked.

Rehabilitate dwellings, giving them the attention they deserve implies to address

maintenance issues, rather than wait for emergencies.

As mentioned before, including vegetation within the urban fabric not only will please

inhabitants but also improve living conditions by renewing air and compensate for heat

release from concrete during the night. Strategies such as vertical gardens and green

roofs (even urban farming involving the communities) are small but decisive steps

towards re-greening our world.

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Figure 8: Green wall at ICON Hotel (Personal Photograph)

Facades are the buildings skins and are the face of the city. For Hong Kong, a scheme

could be developed to improve the unity of facades and achieve a specific style

encompassing graphic elements from Art-Deco past (round shaped openings, balconies,..)

as well as characteristic Tong Lau* colors. This will create a sense of belonging to

dwellers by branding their neighborhood. In the scheme, living walls, sizes and

orientation of openings are key elements of a facade impacting climate control.

C/ District Level

As Peter Cookson Smith expresses, "It is no coincidence that the more dynamic parts of

the city [...] are situated in older multi-use areas" (2006, p 129); indeed, the vitality of multi-

layer activity districts are impossible to recreate through regularized urban planning and

that is why it is essential to keep the human scale by renovating slowly accumulated

buildings rather than erase and plan everything from scratch.

Moreover large redevelopments alter the air flow of entire district and create "canyon

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effects*" where pollution get trapped at street level, that is leaving mixed height buildings

blend is fundamental to a favorable urban landscape.

To revitalize an area, creation of more green spaces, pedestrian zones, traffic control

will participate in making possible the street activity essential to Hong Kongers without

compromising their health. Not only are those activities an essential aspect of Hong Kong

culture, but the less time people spend in air conditioned spaces, the less energy

consuming malls are going to be built. Pedestrians will not be pushed away to higher

platforms but will recover their rights over the territory.

These investments will be profitable by attracting of new high-income tenants or high-

tech green oriented companies and will create a more mixed social background.

For leisure activities as well as for air circulation (avoiding a wall effect*) a shores

preservation scheme has also to be developed.

D/ Spiritual Level

The state of mind of stakeholders makes a big difference in shaping their surroundings

and appreciation of heritage and local culture is a key step to revitalize people and

business. Hong Kong history shows many transformations and people have always found

a way to adapt while keeping local specificity: it is important that Hong Kongers appreciate

how much this constant variation is its very essence of collage city* in Colin Rowe's

sense. Preservation, environment-friendly ethics and economic vitality are closely tied

because they put the people back in charge instead of imposing an unadapted

international style that erases their city and their identities.

Accepting layers, mixing old and new construction, high and low incomes, urban zones

with green zones, higher structures with low rises, etc.. is the path to a more harmonious

environment and architecture and design should be the means for communities to link

their future with the past, in an informal spontaneous way.

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Figure 9: Renovated Tong Lau in Hong Kong (Personal Photograph)

Lastly, a city with a plan allows for more confident, hopefully green, future and therefore

attracts investors as well as tourists and will make possible for Hong Kong to keep its

status of World City.

Conclusion

While Hong Kongers are more and more sensitive to environmental related issues such as

pollution or climate change, sky scrapers are still built. Indeed, the local belief that "new is

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better" combined with an over-emphasis of land scarcity, leads to speculative new

developments. Yet, if they want a better and healthier future, Hong Kong people will have

to realize that they have no choice but retrofitting their existing housing stock ; furthermore,

they will soon discover how environment-friendly investments do not mean new and

sustainable is not opposed to economic growth.

On the contrary, preservation, sustainability and profitability are linked and being aware of

this will put the people back at the center of the city. The directions to create a sustainable

environment are simple: avoid over-regularized planing of urban areas but engage in

rejuvenating aging building and mixing a variety of spaces and shapes to allow

spontaneous informal activities that make Hong Kong's vitality unique.

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List Of References

Books

Bay, J. & Ong B. 2006, Tropical Sustainable Architecture, Elsevier, Burlington, USA.

Cookson Smith, P. 2006, The Urban Design of Impermanence, MCCM Creations, Hong Kong

Kwok, A. & Grondzik, W. 2011,The Green Studio Handbook second edition , Elsevier, Burlington, USA.

Rowe, C.& Koetter, F. 1984, Collage City, The MIT Press, Cambridge, MA, USA

Speer, A. 2009, A Manifesto for Sustainable Cities, Prestel, Munich Berlin London New York.

Research Papers

Durmisevic, E. 15 June 2009, Lifecycle Design of Buildings,Systems and Materials, ConferenceProceedings, International Council for Building Research Studies and Documentation (CIB), Netherlands.

Edge, S. and Thilakaratne, R. , Sustainable cities for our future, Woods Bagot Public Paper Isuue 0815

Lai, C. August 2010, Treating the symptoms a critical review of Urban Renewal in Hong Kong, CivicExchange, Hong Kong.

Ng, E. 2005, Feasibility Study for Establishment of Air Ventilation Assessment System, Department ofArchitecture, CUHK, Hong Kong

Townshend, D. 2007, Study on Green Roof Application In Hong Kong, Architectural Services Department,Hong Kong

Periodicals

2007, 'Hong Kong the Eco-City, Green Urban Planning', Hong Kong Industrialist, July 2007, pp 16-27

2010 'Act Locally, Share Globally -Why City Mayors are Critical in the Fight Against Climate Change,Sustainability Asia, Issue2, pp 27-28

2011, 'Retrofitting Existing Buildings: The low cost, high volume solution to climate change', SustainabilityAsia Pacific, Issue4, pp 10-15

Acuna, J. 2010 'Wanchai 2010:towards a sustainable urban transformation', HKIA Journal, Issue 48, pp 32-33

Brooke, N. 2010 'Building a Sustainable Hong Kong', Sustainability Asia, Issue1, pp 26-27

Ng, E. 2010, 'Designing for Thermal Comfort and Air Ventilation in High Density City Conditions - AirVentilation Assessment System (AVAS)', HKIA Journal, Issue 48, pp24-31

Wilson, K. and Cochrane, J 2010, 'Revamping Old Asia', Development Asia, Year III, Number V1 January

March 2010, pp 23-24

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Web References

Author Unknown 01 June 2012. An overview on air quality and air pollution control in Hong Kong,viewed 01 June2012

Author Unknown 2002, Urban Design Guidelines for Hong Kong, viewed 31 May 2012

http://www.pland.gov.hk/pland_en/p_study/comp_s/udg/udg_es/udg_es_eng.pdf>

author unknown 2003. Maintenance and resource manual: rehabilitation vs. new construction, viewed 31May 2012

Author Unknown 2012. Database: outdoor air pollution in cities, viewed 31 May 2012

Author Unknown 24 November 2011. Conserve and Revitalize Hong Kong Heritage, viewed 31 May 2012

Author Unknown 5 January 2012. Heritage Impact Assessment, viewed 31 May 2012

Author UnknownAugust 2011. Hong Kong Planning Standard and Guidelines, viewed 31 May 2012

Author Unknown February 2011. Urban Renewal Authority Strategy, viewed 31 May 2012

Author Unknown February 2012, Census and Statistics Department Hong Kong Special AdministrativeRegion, viewed 31 May 2012

Author Unknown HOK Hong Kong Office Green Retrofit Greening the Workplace, viewed 31 May 2012

Author Unknown September 2011.Air quality and health, viewed 31 May 2012

Chan, B. 2011 Combating Climate Change Energy Saving and Carbon Emission Reduction in Buildings,viewed 31 May 2012

Dewolf, C. 1 October 2010. Putting life back into Hong Kong's tong lau apartments, viewed 31 May 2012

Figueiro, M. Rea, M Rea, A & Stevens, R, Daylight and Productivity A Field Study, viewed 01 June 2012

Kilburn, M. Wong, M 17 January 2012. Revised Hedley Environmental Index Triples Estimates ofDeaths Attributable to Air Pollution in Hong Kong - Civic Exchange press release,viewed 31 May 2012

Moor, M. & Lloyd-Jones, T. 22 May 2009. Retrofitting Sustainability to Historic City Areas: an Urban DesignApproach, viewed 31 May 2012

Ng, T. 3 April 2007, HK Short of Breath from 'Wall Effect', viewed 02June 2012

Roy, B. 15 December 2011.Old faces, new lifts'Green' makeovers of buildings can go a long way in savingenergy, viewed 31 May 2012

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Bibliography

Wolf, M. 2009, Hong Kong Inside Outside, Asia One Books, Hong Kong

Young, D. 2009, My HK, GOD Limited, Hong Kong

Wu, R and Canham, S. 2009, Portraits from Above Hong Kong Informal Rooftop

Communities, MCCM Creations, Hong Kong

Yu, V. 2007, Our Home, Shek Kip Mei, MCCM Creations, Hong Kong

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Glossary

Canyon effect: Street canyons (also called urban canyons) are streets where high

buildings prevent air flow and consequently, particles from vehicle

engines get trapped at ground level. This is called Canyon Effect.

Collage City: Expression taken from Colin Rowe's book title in which he questions

the planning principles of modern movement lead by Le Corbusier

and advocates that the City was formed by successive layers, by

assembling various elements. The radical vision of the Modernists

and their "Tabula Rasa" is opposed to an urban tradition based on

the gradual sedimentation of Cities.

Double-glazed window: Window with two panes of glass and a space filled with air or other

gas between them; to reduce heat and noise transmission.

Greenhouse gas: Any gas that absorbs infrared radiation in the atmosphere. If the

atmospheric concentrations of these greenhouse gases rise, the

average temperature of the lower atmosphere will gradually

increase. This is called Greenhouse effect. (United States EPA

definition)

Living Wall: Vertical gardens created by planting vegetation on some sort of

growing medium on the outward face of the wall.

Tong Lau: Southern China tenement buildings from late of 19 th century to late

60s, designed for both commercial (ground floor) and residential use.

Urban Heat Island effect: The term "heat island" describes built up areas that are hotter than

nearby rural areas. The annual mean air temperature of a city with 1

million people or more can be 1.85.4F (13C) warmer than its

surroundings. In the evening, the difference can be as high as 22F

(12C). Heat islands can affect communities by increasing

summertime peak energy demand, air conditioning costs, air

pollution and greenhouse gas emissions, heat-related illness and

mortality, and water quality. (United States EPA definition)

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VOC materials: Volatile organic compounds, or VOCs are organic chemical

compounds whose composition makes it possible for them to

evaporate under normal indoor atmospheric conditions of

temperature and pressure. (United States EPA definition). Many

VOCs are dangerous to human health or cause harm to the

environment.

Wall effect: Impact of high rise buildings blocking the flow of fresh winds

(especially when coming from the sea).

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essay- why hk needs to rehabilitate to become sustainable (with illustrations)

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