Appraising and Explaining Unauthorized Building Works in Apartment Buildings in Hong Kong

by

Daniel Chi Wing HO Department of Real Estate and Construction

The University of Hong Kong Hong Kong SAR

People’s Republic of China E-mail: danielho@hku.hk

Kwong Wing CHAU

Department of Real Estate and Construction The University of Hong Kong

Hong Kong SAR People’s Republic of China E-mail: hrrbckw@hku.hk

Yung YAU*

Department of Public and Social Administration City University of Hong Kong

Hong Kong SAR People’s Republic of China E-mail: y.yau@cityu.edu.hk

Paper submitted to

Building Research & Information * Please send comments to: Dr. Yung Yau Assistant Professor Department of Public and Social Administration City University of Hong Kong Tat Chee Avenue Kowloon Tong Kowloon Hong Kong Telephone No.: (852) 2788 8958 Fax No.: (852) 2788 8926 E-mail: y.yau@cityu.edu.hk

APPRAISING AND EXPLAINING

UNAUTHORIZED BUILDING WORKS

IN APARTMENT BUILDINGS IN HONG KONG

ABSTRACT

Hong Kong is a densely-populated city where high-rise buildings are common.

In such an environment, building failures can pose a serious threat.

Unauthorized building works (UBWs), which are constructed without prior

approval and consent from the government, contribute a lot to the spate of

building-related accidents in the territory. In particular, those UBWs attached to

the external envelopes of buildings not only endanger the lives of their occupants,

but also the lives of passers-by and even the properties themselves. This study

provides an overview of the proliferation of UBWs in Hong Kong and is the first

empirical study on this topic. After inspecting 323 apartment buildings in two

districts, we analyzed factors affecting the proliferation of UBWs and found that

buildings with amenities incorporated into their designs generally had fewer

UBWs on their external envelopes. However, owners’ associations or property

management companies did not have any effects on UBW numbers for their

buildings. These findings have far-reaching implications on the formulation of

government policies for building safety. Promotion of forming statutory owners’

associations or employing property management companies is not effective in

containing the UBW problems in Hong Kong. Resorts should be made to

community education and stricter law enforcement.

KEYWORDS

Apartment buildings; building safety; unauthorized building works; Hong Kong

LENGTH OF MANUSCRIPT - 5,992 words

INTRODUCTION

In the past, people settled in caves and on trees to hide themselves from

the weather and predators. Nowadays, they live in different types of residences

and different settings. While the forms or styles of shelters have changed

continuously to meet people’s ever-changing requirements, shelter has been a

basic human need since the dawn of humanity (Pryor, 1983; Lawrence, 2004).

The desire for a shelter originated from the understanding that the world is seldom

attuned exactly to people’s physiological and social needs. In order to serve its

purpose, a shelter should not only be weatherproof and comfortable, but also safe.

Safety, as defined by the World Health Organization (WHO, 1998), is “a

state in which hazards and conditions leading to physical, psychological or

material harm are controlled in order to preserve the health and well-being of

individuals and the community” (pp.6). With reference to this definition, the

assertion that building safety “offers occupants freedom from hazards or risks”

(Al-Homoud and Khan, 2004, pp.300) is not full. Other than the occupants, the

well-being of the passers-by should be considered. This is particularly relevant

to compact cities like Hong Kong, where development density is so high that any

building failure can be disastrous.

Among the numerous threats posed by the built environment on

community safety, the proliferation of unauthorized building works (UBWs) has

long been a major problem. Although a lot of ink has been spilt on this topic

(e.g. Chan, 1998; Davison, 1990; Lai and Ho, 2001; Leung and Yiu, 2004; Yiu et

al., 2004; Yiu, 2005; Yiu and Yau, 2005), associated empirical studies have been

rare. In this light, this study empirically explores the factors that affect the

degree of the UBW problem in Hong Kong’s apartment buildings. Given that

the majority of Hong Kong’s population lived in high-rise apartment buildings,

the building occupants and the general public are prone to UBW hazards. Public

concern over these calamitous problems has been further amplified by the recent

spate of building-related accidents in the territory. Therefore, empirical studies

like this one are necessary to provide valuable insight into the formulation of a

sensible and effective building safety policy.

PROLIFERATION OF UNAUTHORIZED BUILDING WORKS

In Hong Kong, there are about 39,000 private multi-storey apartment

buildings, most of which are in multiple ownership, scattered all over the territory

(Housing, Planning and Lands Bureau, 2004). This stock of buildings provides a

total of about 1.04 million residential units (Rating and Valuation Department,

2006). However, the problems with UBWs have upset the safety of the built

environment in Hong Kong for many decades. Section 14 of the Buildings

Ordinance (Chapter 123 of the Laws of Hong Kong) stipulates that the Building

Authority’s approval and consent are required before any building works may

commence.1 Building works that are in contravention of this stipulation are

regarded as UBWs (Yiu et al., 2004; Yiu and Yau, 2005).

According to the Planning and Lands Bureau (2001), there were about

800,000 UBWs in Hong Kong, including illegal rooftop structures. In addition,

there were about 220,000 advertisement signs erected without the consent of the

Building Authority. As shown in Fig. 1, the number of reported UBWs received

by the Buildings Department in 2005 doubled the total in 1996. During the

period between January 1990 and December 2002, there were 21 deaths and 135

injuries inflicted by UBW-related accidents (Leung and Yiu, 2004).

[Fig. 1 about here]

Enforcement against UBWs

Section 24(1) of the Buildings Ordinance empowers the Building

Authority to serve statutory orders on building owners for the removal of any

UBWs within a specified period of time. These orders are also known as

“removal orders”. Every removal order specifies the UBWs to be removed, and

their owners are required to re-instate the parts of the building so affected in

accordance with original approved building plans (Chan and Chan, 2003). If the

removal and reinstatement works are substantial or involve structural works, the

Building Authority may specifically require owners to appoint an authorized

person or registered structural engineer to coordinate and supervise the works on

the owners’ behalf. A registered general building contractor should also be

appointed to carry out the works under the supervision of an authorized person.

Under Section 40(1B)(b) of the Buildings Ordinance, non-compliance

with a statutory order issued by the Building Authority without reasonable excuse

is a criminal offence. An offending owner may be liable, upon conviction, to a

fine of HK$200,000 and imprisonment for one year. Defaulted owners may also

be subject to a further fine of HK$20,000 for each day s/he fails to comply with an

order. All statutory orders issued under the Buildings Ordinance are copied to

the Land Registry for registration against the titles of owners. The registration

will only be discharged when the owner complies with a subject and the Building

Authority issues a letter of compliance (Buildings Department, 1997).

However, the government cannot deal with all the UBWs in the city due to

resource limitations. Therefore, it has to prioritize its enforcement actions.

Under the policy, which it announced in April 2001, the Building Authority gives

priority to the removal of the following types of UBWs (Chong, 2003):

(i) items constituting an obvious or imminent danger to life or property;

(ii) new items, irrespective of the date of completion of the building and

where they were carried out;

(iii) items in or on buildings, podiums, and rooftops, and in yards and

lanes (including unauthorized site formation works) constituting a

serious hazard or a serious environmental nuisance;

(iv) substantial individual items;

(v) items in or on individual buildings with extensive UBWs;

(vi) items identified in buildings or groups of buildings targeted for large

scale operations or maintenance programmes; and

(vii) unauthorized alterations to or works on the environmentally friendly

features of a building (e.g. balconies or sky gardens) for which

exemption from the gross floor area was granted by the Building

Authority.

Reasons for UBW Proliferation

Lai (2003) reckoned that the proliferation of UBWs in Hong Kong is due

to the lack of developable land in the city. The pressures from continuous

population growth and the influx of immigrants since the 1960s pushed up

demand for low-cost housing (Buildings Department, 1998). Under this

circumstance, people erected UBWs in order to maximize their usable floor areas.

The UBW problems have been further aggravated by poor building management

(Lai and Ho, 2001), high enforcement costs (Yiu, 2005), and ambiguities in the

Buildings Ordinance (Yiu and Yau, 2005).

Definitely, poor management of the buildings has contributed a great deal

to the gravity of the UBW problem in Hong Kong. One of the major obstacles to

effective building management in the territory is the high-rise pattern of building

development. Obviously, the management of multiple ownership high-rise

apartment buildings is much more difficult than that of low-rise, low-density

residential developments (Fong, 1985). The difficulties are usually ascribed to

the ownership arrangement in apartment buildings (Bailey and Robertson, 1997;

Yip and Forrest, 2002). Under the current ownership system in Hong Kong,

those shared areas and facilities, or common parts, in an apartment building are

co-owned by all owners of the constituent individual flats of the building. While

enjoying their ownership (and also the right of use), owners need to shoulder the

responsibility for keeping these common parts in good condition. However, in

order to carry out improvements to these common parts in an apartment building,

collective action is required because consent from all co-owners is a prerequisite

for the commencement of works. Intricacies often arise in obtaining owners’

consents for the works with regard to the common parts, which eventually turn

into maintenance and management problems for the building (Bailey and

Robertson, 1997).

The problems in building management and maintenance are frequently

exacerbated by the high development intensities of the buildings. Although the

large scale of a residential development may offer cost efficiency (e.g. the unit

costs of spare parts for building services and fittings are lower due to discounts

from bulk purchases) (Wood, 2003), the large number of households involved

may invoke tribulations for coordination and negotiation. An increase in the

number of dwellings in a building will, at the same time, introduce more

stakeholders. Therefore, more people will have a say on issues related to the

management and operations of a building, including major renovation and

improvement works. Difficulties in gathering opinions and obtaining consents

from numerous owners inevitably arise (Walters, 2002; Lai and Chan, 2004)

because they do not necessarily have similar objectives and tend to pursue their

own interests rather than compromise to resolve any problems (Leather and

Mackintosh, 1992; Walters and Hastings, 1998). As a result, it is more difficult

to have a consensus among the co-owners of a building, and thus collective

actions against individual owners’ improper acts (e.g. construction of UBWs) are

often hindered.

Last, but not least, the proliferation of UBWs could be ascribed to the

lack of provision of amenities space. In Hong Kong where Chinese households

dominate, it is the tradition for the householder to dry clothes in open or airy areas

regardless of the modern advances in washer and dryer technology (Wong et al.,

2005). For this reason, many households in Hong Kong hang their clothes on

drying racks or poles projecting from the external walls of their buildings.

However, some of these drying facilities are not approved building works, and

their safety standards are questionable. These building elements constitute

UBWs. Another obvious example is the air-conditioner support frame. As

Hong Kong is located in a sub-tropical region, air-conditioners have become an

indispensable home appliance to maintain a comfortable indoor environment.

However, many buildings constructed before 1990 do not provide any platform

(which is usually made of a more durable material, such as reinforced concrete) to

accommodate room-typed air-conditioners in their original design.

Effects of UBW Proliferation

UBWs affect building safety because their own structural soundness tends

to be uncertain, and this affects approved building works on or near which they

are built (Choy, 1998). In this regard, the consequences of UBW proliferation

can be influential and multi-faceted. First, there is a direct link between UBW

problems and associated casualties, property losses, and social costs (e.g.

hospitalization and legal costs). As aforementioned, fatal accidents involving

UBWs are not rare in Hong Kong. Besides, UBWs pose problems to the

structural stability and fire safety of a building (Lai and Ho, 2001).

Other than these safety problems, the presence of UBWs in a building can

jeopardize the health of its residents. UBWs such as advertisement signs and

metal cages are constructed along the external walls of buildings and thus often

block natural light and ventilation from entering them. Chan (2000) added that

over and above the direct safety hazards, these unauthorized structures might

indirectly aggravate the problems of building decay. Many of the UBWs and

advertisement signs were erected along the exterior and flat roofs of buildings so

that they hinder attempts to repair and maintain these buildings. Needless to say,

the presence of UBWs on a building, particularly on the façade, degrades its

external appearance. In addition to their adverse impact on safety, aesthetics,

lighting, and ventilation, UBWs render the titles of the properties concerned

defective. This would eventually restrict property transactions, which is

detrimental to the real estate market in the long run.

UBWs on Building Envelopes

Among all types of UBWs, the ones attached to the building envelopes,

particularly the external walls of buildings, are the most hazardous because they

not only affect the safety of occupants, but people and properties in the building’s

vicinity as well. Illegal appendages commonly seen in Hong Kong include cages,

drying racks, flower racks, lightweight canopies, and air-conditioner supports.

This type of UBW is very common in the territory because it is a relatively easier

way to increase the amount of usable space or amenities for residents. Let us say

that the owner of a particular unit in an apartment building would like to increase

the floor area of his/her flat by expanding the flat out onto the common corridor.

Other owners may feel that their property rights are infringed, as the corridor they

currently use becomes more constricted. Complaints or objections from these

owners against the UBW will arise more readily. One the other hand, building

owners are less conscious about UBWs along the external walls of a building

because they hardly affect the personal spaces under normal situations. Only

when some extensive UBWs are constructed to cause intolerable nuisance to other

residents (e.g. blocking their enjoying of the natural lighting or leading to water

seepage) will the latter raise objections.

EXPLANATORY MODEL FOR THE NUMBER OF UBWS IN HONG

KONG

From the above, it is quite clear that studies describing or explaining UBW

proliferation in Hong Kong abound. However, none of these studies are

supported by empirically data. In this light, this study investigates the issue

using empirical data in Hong Kong. As far as the authors are aware of, this

study is the first empirical study on the determinants of the proliferation of illegal

building works throughout the world.

We measure the extent of proliferation of UBW in an apartment building

by the number of UBWs per number of dwelling unit in the building. From the

literature reviewed above, variation in the extent of proliferation of UBW are due

to factors that can be broadly classified into building characteristic related factor

and factors that relate to the mode of management of the building.

Mathematically we can specify the relation as:

),( MGMTBLDGfUBW (1)

where UBW is the number of UBWs per number of dwelling unit in the building,

BLDG and MGMT are vectors of characteristics and management mode of

building respectively.

In principle, BLDG and MGMT are analogous to a building’s hardware

and software, respectively. BLDG is a set of physical characteristics of the

building that are results of design and disposition of a building, which are usually

difficult or costly to change once a building has commenced operations. On the

other hand, MGMT represents a set of factors related to how the building is

managed and are usually easier to change even after a building has been occupied.

For the purpose of empirical analysis, we have identified seven observable BLDG

variables and four MGMT variables and operationalized equation (1) as follows:

),,

,,,,,,,,(

LOCATIONDRYFACACHOOD

PMMACOCIOESTATEUNITSIZEAGEfUBW (2)

where AGE is the age of the building, measured in years;

SIZE is the average size of the dwelling units in the building, measured

in square metres;

UNIT is the total number of dwelling units within the building;

ESTATE is a dummy variable that equals 1 if the building comes from

an estate-type development, and zero if otherwise;

IO is a dummy variable that equals 1 if there is an owners’ corporation

formed for the building, and zero if otherwise;

OC is a dummy variable that equals 1 if there is an owners’ committee

formed for the building, and zero if otherwise;

MAC is a dummy variable that equals 1 if there is a mutual aid

committee formed for the building, and zero if otherwise;

PM is a dummy variable that equals 1 if an external property

management agent is employed for managing the building, and zero if

otherwise;

ACHOOD is a dummy variable that equals 1 if building-integrated

air-conditioner hoods are provided in the building, and zero if

otherwise;

DRYFAC is a dummy variable that equals 1 if building-integrated

drying facilities are provided in the building, and zero if otherwise; and

LOCATION is a vector of dummy variables representing the location of

the building.

Usable Space

The lack of usable space in an apartment unit is a potential motivating

factor for the construction of most UBWs. On the contrary, a larger average size

of the units in a building can result in more UBWs in the building because there

are more bedrooms accommodated in the building. Given that it is very common

to have a window-type air-conditioner in each bedroom in Hong Kong, the more

bedrooms in each dwelling unit means more unauthorized support frames for

air-conditioners if no approved building-integrated air-conditioner platforms are

available in the building. From the above, therefore, it is difficult to envisage the

effects of SIZE on the number of UBWs present in an apartment building.

Development Scale

Regarding the factors of building management, the number of dwelling

units in a building, UNIT, is used to measure the effects of development intensity

on the extent of UBW proliferation. The more dwelling units there are in a

building, the more interested owners will be in the building, leading to more

coordination difficulties in managing the building (Walters, 2002; Lai and Chan,

2004). As a result, it is expected that the per-unit number of UBWs in an

apartment building increases with the number of dwelling units in the building.

Similarly, the variable ESTATE also measures the scale effect of the

residential development investigated. This dummy variable equals one if the

apartment building is a part of an estate-type development, i.e. one containing

more than one apartment building. The expected effects of this variable on the

per-unit number of UBWs are complex. On one hand, estate-type development

generally means more number of dwelling units in total. As aforementioned,

involvements of more interested owners may hinder property management of a

building, resulting in an increase in the average number of UBWs in the building.

On the other hand, each building in an estate-type development imposes

externality effects on other buildings in the estate. For example, proliferation of

UBWs in one building lowers the property prices in other buildings in the same

estate, creating negative externalities (say, owing to poor aesthetic appearance or

increased safety risk). With a view to maximize the common value of the

properties, property owners in estate-scale developments tend to participate

actively in the control of UBW construction in their estates.

Building Management Mode

Other building management factors incorporated into the explanatory

model are connected to the structure of building management. Since the

management of the common parts in apartment buildings involves many

coordination problems, the formation of some form of organization or owners

association seems necessary. To counter the management problems in apartment

buildings in Hong Kong, the government has advised owners to either coordinate

the management matters themselves by forming and participating in statutory

owners associations, and/or employing external property management companies

or property management agents (PMAs), as termed by the authority (Home

Affairs Department, 2001). In short, a PMA is a paid agent hired to help

building owners supervise cleaners, security guards, and contractors, plus handle

correspondence, manage financial accounts, convene meetings, and coordinate

repair and maintenance works. Irrespective of the existence of any PMA in a

building, owners can form their own owners associations to manage their

buildings.

The owners association recommended by the government is known as an

owners’ corporation or incorporated owners (IO). An IO is an independent legal

entity formed under the Building Management Ordinance (Chapter 344 of the

Laws of Hong Kong).2 It mainly serves as a representative of all co-owners of a

multi-storey building or development. By virtue of the Building Management

Ordinance, an IO is empowered to convene general meetings of owners, and to

enforce resolutions arrived at the meeting (Kent et al., 2002), provided that the

rulings and procedures of the meetings strictly follow those provisions set out in

the ordinance. Besides, an IO possesses power sourcing from the statute to

appoint, terminate, and monitor those services provided by the PMA (Kent et al.,

2002; Ho et al., 2006). Since an IO is a statutory entity, it is empowered to sue,

but it is also liable to be sued (Home Affairs Department, 2001). In principle,

building management can be facilitated by the formation of IO because an IO can

serve a representative of the co-owners to deal with the management and

maintenance issues of a building, as provided in laws.

These are the unique powers of an IO that are generally not available in

non-statutory owners associations, such as owners committees (OCs) and mutual

aid committees (MACs). Technically speaking, an OC is an owners’ association

set up and governed in accordance with the conditions of a deed of mutual

covenants (DMC).3 In spite of its non-statutory nature, an OC takes similar

duties as an IO to provide a channel for effective communication among

co-owners in a building. Besides, with the power stipulated in the DMC, an OC

also is authorized to monitor the work of a PMA, if any, on behalf of all the

co-owners (Ho et al., 2006). In contrast, the standing of an MAC is more

informal than an OC. Its major function is to promote good neighbourliness

among owners and tenants of a building so an MAC is roughly similar to a social

community formed by the residents (Ho et al., 2006). Although an MAC can

help carry out basic building management work, it cannot make decisions for all

co-owners in reference to the terms laid down in a DMC like what an OC can do.

To a certain extent, an MAC is nothing more than an advisory body carrying no

solid power (Ho et al., 2006). Its effect on building management is minimal

because it can at most help initiate negotiations among residents on building

management issues.

There are plenty of studies advocating the significance of a PMA and IO in

the management of a building. For example, Yip (2001) suggested that the

general meetings regularly convened by the IO offered a channel for the

co-owners to give comments and advice on building management issues, allowing

more-informed decisions to be made. Kent et al. (2002) asserted that the

formation of owners associations like an IO was essential for the effective

management of a building, resulting in fewer problems and better conditions for

the building. This point of view was supported by an empirical study by

Werczberger and Ginsberg (1987). Based on Olson’s (1965) seminal group

theory, Walters and Kent (2000), Walters (2002), and Chen and Webster (2005)

highlighted the significance of an IO to serve as a central authority for

coordinating owners to take collective actions. Lai and Ho (2001) opined that

PMAs had better expertise in using legal means to contend with the problem of

UBW proliferation. From the above, it is logical to envisage that the presence of

an IO and/or a PMA in an apartment can help reduce the number of UBWs per

unit in the building.

Other Building Variables

UBWs, such as air-conditioner support frames and drying racks, are

constructed to enhance the properties’ amenities. Intuitively, the presence of

these unauthorized appendages is associated with the non-provision of essential

building features like drying facilities and air-conditioner hoods in the original

building design. For that reason, apartment buildings with these provisions

integrated into the building design should have fewer illegal appendages in the

building. Last, the factors AGE and LOCATION are included in the model to

control the possible ageing and location effects, if any, on the number of UBWs

present in the building.

DATA FOR REGRESSION ANALYSIS

Sources of Data

We test the relationships between the dependent and independent variables

by empirically estimating Equation (2) using Ordinary Least Squares technique.

The data for the empirical tests were obtained from the Building Quality Index

research project undertaken by the Faculty of Architecture at the University of

Hong Kong.4 In that project, the research team successfully surveyed 148

residential buildings in Yau Tsim Mong (YTM) and 175 residential buildings in

the Eastern District in 2004 and 2005, respectively. They also studied the

approved building plans (obtainable from the Buildings Department) for these

buildings and documents on management modes (obtainable from the Home

Affairs Department), supplemented by interviews with management personnel

on-site.

Two reasons underlie the selection of these two districts. First, YTM and

the Eastern District are the areas with the largest number of residential units in

Hong Kong. According to the Census and Statistics Department (2005), there

were 103,906 and 125,028 private residential units in YTM and the Eastern

District, respectively, at the end of 2004, accounting for 12.08 percent and 10.04

percent, respectively, of the total stock of private residential units in Hong Kong.

Second, there is a wide variety of residential buildings in YTM and the Eastern

District, ranging from post-war tenement blocks, residential buildings resting on

commercial podiums, to newly built large-scale residential estates. This

provides a high degree of variation in the age, design, and management regime of

the buildings, which is essential for obtaining a diversified sample for analysis.

These two reasons suggest that YTM and the Eastern District are representative

enough for us to study the quality of Hong Kong’s living built environment.

According to the government’s database,5 there were 2,716 and 1,749

private apartment buildings in YTM and the Eastern District, respectively. Our

by-district samples represent respectively approximately 5.5 percent of the total

stock of private residential building in YTM and 10 percent in the Eastern

District. Tables 1 and 2 show respectively the physical characteristics and mode

of management of the surveyed buildings. Surveyed buildings in YTM and the

Eastern District were of similar mean ages (around 32 years). Meanwhile, the

average flat sizes of buildings in YTM (53.53 square metres) were, on average,

smaller than those in the Eastern District (62.51 square metres). Buildings in the

sample of the Eastern District were a little taller (14.49 storeys on average) than

those in YTM (11.70 storeys on average). Also, since the sample contained

more lager estate-type developments from the Eastern District, the average scale

of development was larger than that in YTM. Overall, 118 buildings (36.53% of

the whole sample) were managed by owners’ corporations and property

management companies. Ninety-two (28.48%) buildings were managed by an

IO only, while forty-eight (14.86%) were managed by property management

companies only. The remaining sixty-five (20.13%) buildings were not managed

by either.

[Table 1 about here]

[Table 2 about here]

Among the various types of UBWs, only illegal appendages formed the

foci of our analyses. The reason for this confinement is that these illegal

projecting structures affect not only the occupants of and visitors to the buildings,

but also endanger the safety of passers-by and the properties of others.

Conversely, other UBWs, like those affecting a building’s fire safety, may not

have significant, direct impacts on the community.

Illegal Appendages Identified in the Survey

Taken as a whole, each surveyed building had an average of 107.88

unauthorized appendages at the time of inspection. However, the variation was

quite large. The maximum number of unauthorized appendages found was 869,

while zero was the minimum, with a standard deviation of 132.15. The average

number of unauthorized appendages per residential unit in the surveyed buildings

was 2.64 with a maximum of 24.50. Table 3 summarizes the statistics by the

type of unauthorized appendage. On the whole, an air-conditioner support frame

was the most common type of unauthorized appendages, followed by a drying

rack.

[Table 3 about here]

In Table 3, the unauthorized appendages identified were classified into two

categories according to their safety risks (Buildings Department, 2005). One

category is high-risk or actionable unauthorized appendages, and includes metal

cages and solid canopies. These UBWs pose imminent dangers to the

community so immediate removals should be accorded. Conversely, the other

category is low-risk or non-actionable unauthorized appendages which pose a

relatively limited degree of hazard on occupants and the public. On account of

the comparatively lower risks associated and the amenity offered to building users,

these low-risk UBWs are currently tolerated by the Buildings Department.3

EMPIRICAL RESULTS AND DISCUSSIONS

Results of the Regression Analysis

Table 4 summarizes the results of the regression analysis using the data

for 323 apartment buildings. We found the variables AGE, SIZE and UNIT to be

positively correlated with the per-unit number of UBWs in the buildings. Their

estimated coefficients were statistically significant at least at the 10% level. On

the contrary, the variable ESTATE was found to be negatively correlated with the

average UBW number and the estimated coefficient was statistically significant at

the 1% level. As for the variables ACHOOD and DRYFAC, their coefficients

were negative but the estimated coefficient of DRYFAC was statistically

significant at the 1% level while that of ACHOOD was insignificant.

Furthermore, none of the variables regarding the mode of building management

had a significant impact on the per-unit number of UBWs in the apartment

buildings.

[Table 4 about here]

We also performed regression analyses on the per-unit numbers of

high-risk UBWs (HRUBW) and low-risk UBWs (LRUBW), and their results are

summarised in Tables 5 and 6, respectively. The estimated coefficient of the

variable SIZE was positive and statistically significant for both models. Also,

the variables pertinent to building management mode again did not show any

significant influence on the per-unit number of UBWs in both analyses. The

estimated coefficient of the variable ESTATE, however, became insignificant in

both cases. The positive effect of AGE was retained in the model explaining the

number of high-risk UBWs but not in that for low-risk UBWs. Both the

variables ACHOOD and DRYFAC were found to have negative and statistically

significant impacts on the per-unit number of low-risk UBWs while that of

high-risk UWBs was only significantly affected by the variable ACHOOD.

[Table 5 about here]

[Table 6 about here]

Effects of Building Characteristics on the UBW

The results of the regression analysis using LRUBW as the dependent

variable indicate buildings with air-conditioner hoods and drying facilities

incorporated into their designs generally had fewer low-risk unauthorized

appendages in each dwelling unit, compared to those without these

building-integrated facilities. The provision of air-conditioner hoods reduces the

average number of UBWs in each unit by 1.32, while the provision of drying

facilities reduces this number by 0.64. While the results for the other two

models are different, it is still say that these amenity features can help reduce the

number of UBWs in a building, particularly for those low-risk UBWs such as

illegal drying racks and air-conditioner support frames. Therefore, the

government should observe the need for these amenities when apartment

buildings are designed and developed in future. While the government is on the

right track to promote the provision of air-conditioner hoods or platforms and

utility platforms by means of gross floor area concession, it should also consider

more determined measures, such as the mandatory provision of these amenity

features.

Nonetheless, the average size of a dwelling unit in each building had a

positive, rather than negative, effect on the number of unauthorized appendages in

each unit, irrespective of the choice of dependent variable. A lack of space was

probably not one of the major causes of UBW proliferation in the buildings we

investigated. Yet, caution must be taken when interpreting the results. Since

we did not input the populations of these buildings into the model, the average

unit size alone may not truly reflect each building’s population density, which we

think is more relevant to the number of UBWs present in the buildings.

However, there was no building-based data for population available in Hong

Kong, so we could not ascertain the actual effect of the living density on the UBW

number.

Effects of Development Scale on the UBW Number

Unfortunately, the analysis results about the effects of development scale

on the per-unit number of UBWs were mixed in this study. For the model using

UBW as the dependent variable, the number of dwelling units had a significant

positive effect whereas estate-type development had a significant negative effect

on the per-unit number of UBWs. These findings confirm our expectations of

the difficulties in coordination among building owners at the building level and

the common value effects motivating voluntary control of UBWs at the estate

level. Yet, in the other two models, estate-type development did not show any

significant effects, and dwelling unit number was found to have a statistically

significant and negative relationship with average UBW number. In this case,

there is no conclusive result on the relationships between development scale and

the average number of UBWs present. Further studies are recommended to

investigate the linkages.

Effects of Building Management Mode on the UBW Number

Contrary to common belief, buildings with an IO and/or PMA did not

necessarily have fewer unauthorized appendages. This may be attributed to

agency problems associated with building management agents. In many cases,

delegating decision-making powers to the management committee of an owners

association is not fool-proof. For example, an inactive owners association is not

conducive to proper building management (Housing, Planning and Lands Bureau,

2005b). Worse still, there are examples of rival groups being formed within

owners associations (Housing, Planning and Lands Bureau, 2004). This only

worsens, rather than resolves, any management problems. Besides, the

committee members of an IO are supposed to act on behalf of their principals (i.e.,

the building owners). However, due to the rent-seeking behaviour of these

committee members, a weak principal-strong agent situation in which decisions

are beneficial to the committee members themselves, but detrimental to other

owners, often results (Walters and Kent, 2000). For instance, if UBWs are found

in several dwelling units of a building, including the units of the committee

members, the committee members may try to protect their self-interests by not

enforcing the DMC against the offending owners.

Similar agency problems also occur even if a PMA has been employed for

managing a building. In the absence of a check-and-balance mechanism, a

situation with weak principal (i.e, the building owners) but strong agent (i.e., the

PMA) is commonly resulted. In some cases, even if the owners of a building are

not satisfied with the performance of their PMA, it may not be easy to get enough

votes for a resolution to terminate the PMA’s services if the owners are not

well-coordinated. This is particularly the case when an IO for the building does

not exist. In this regard, it is somewhat liberate for a PMA to hunt for its own

benefits (Walters and Kent, 2000). Even worse, the coexistence of an IO and a

PMA in a building may create problems rather than positive synergetic results, as

conflicts often exist between owners associations and PMAs (Cairncross et al.,

1997; Walters and Kent, 2000). All these problems may render the building

management mechanism ineffective in controlling UBWs in an apartment

building. Therefore, the government’s effort to eliminate the problems of UBWs

by promoting IO formation and PMA engagement could be in vain.

CONCLUSIONS

As Hong Kong is a concrete jungle made up of 39,000 private multi-storey

buildings, navigating through this forest of high-rises can be risky. Evidence

shows that UBW proliferation has created many problems to the local community.

In this light, requests for addressing the problem of UBWs have become more

frequent. This study is probably the first empirical study to explain the presence

of UBWs in apartment buildings in Hong Kong. We collected data by inspecting

323 apartment buildings in YTM and the Eastern District and studies plans and

documents in government departments. We use the data to estimate an empirical

model that expresses extent of proliferation of UBWs as a function of the potential

factors. The results of the empirical tests indicated that locality and each

building’s management mode did not have any significant impact on the number

of the unauthorized appendages.

The empirical results provide valuable insights into Hong Kong’s building

safety policies for the government. From the empirical results, the provision of

amenity features in building design could help reduce the number of illegal

appendages in appraised buildings. The government can make these provisions

mandatory in order to eliminate potential UBWs in future developments. On the

other hand, it has been ineffective in promoting IO formation and PMA

engagement to tackle UBW problems. Therefore, the government should take a

bold and determined step to resolve this quandary, particularly in existing

buildings, by way of community education and law amendments. Heavier

punishments and stricter enforcement actions may be required to remove these

offending structures. Few recommend further studies to investigate the effects of

heavier punishments and stricter enforcement by the government against UBWs.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the financial support provided by the

Research Grant Council of the Hong Kong Special Administrative Region (HKU

7107/04E and HKU 7131/05E), the Small Project Funding of The University of

Hong Kong, and the HKU Research Group on Sustainable Cities Seed Grant,

which made this research possible. We would also like to thank the Buildings

Department, Home Affairs Department of the Government of the Hong Kong

Special Administrative Region for their kindly provision of information and

support for the study.

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0

5,000

10,000

15,000

20,000

25,000

30,000

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Nu

mb

er o

f Rep

ort

s o

n U

BW

s

Year

Fig. 1: Numbers of reports on UBWs received by the Buildings Department

Source: Buildings Department (2001, 2007)

Table 1: Physical characteristics of the buildings surveyed in YTM and NP.

Characteristics Maximum Mean Minimum Standard

Deviation

Age (in years) 59.00 32.02 3.00 12.30

Average unit size (in square

metres)

170.20 58.39 19.60 23.45

Number of storeys 40.00 13.17 3.00 7.46

Number of units per

building

500.00 60.44 3.00 73.28

Number of units per

development

12,896.00 149.70 3.00 774.49

Table 2: Distribution of the buildings surveyed by management regime.

Management Regime

Number

of

Buildings

Portion of

Whole

Sample

Managed by PMA and IO 118 36.53 %

Managed by IO only 92 28.48 %

Managed by a PMA but

without any statutory

owners association

- Managed by PMA only 18 5.57 %

- Managed by PMA and OC 5 1.55 %

- Managed by PMA and

MAC

25 7.74 %

Not managed by a PMA

nor a statutory owners

association

- Managed by OC only 1 0.31 %

- Managed by MAC only 4 1.24 %

- Without any form of

management

60 18.58 %

Table 3: Number of unauthorized appendages by type.

Type of Unauthorized

Appendages Maximum Mean Minimum

Standard

Deviation

High-risk Unauthorized Appendages

Solid canopy 3.00 0.07 0 0.35

Light-weight canopy

(exceeding 0.5 metres)

86.00 2.52 0 10.03

Metal frame 44.00 1.51 0 4.62

Metal cage 23.00 0.43 0 1.60

Solid extension 3.00 0.08 0 0.39

Flower rack 37.00 1.13 0 3.74

Low-risk Unauthorized Appendages

Light-weight canopy (not

exceeding 0.5 metres)

315.00 13.49 0 30.14

Air-conditioner support

frame

549.00 67.36 0 86.34

Drying rack 363.00 20.69 0 34.93

Advertisement sign 12.00 0.60 0 1.47

Overall 869.00 107.88 0 132.15

Table 4: Results of the regression analysis on all UBWs

Variable Coefficient t-Statistic

Constant 0.9741 1.8187 **

AGE 0.0248 2.1500 **

SIZE 0.9741 1.8187 #

UNIT 0.0248 2.1500 **

ESTATE -0.0046 -4.1434 *

IO -0.0547 -0.1808

OC 0.2518 0.9479

MAC 0.5339 1.1163

PM -0.1612 -0.5049

ACHOOD -0.2425 -1.2082

DRYFAC -1.4047 -6.0404 *

PE -0.5810 -2.6326 *

MK 0.9206 2.9366 *

YMT 0.4871 1.7456 #

TKT 0.7905 2.1282 **

JD 0.2497 0.7606

TST 0.2755 0.7842

NP 0.6780 2.0661 **

TH 0.7831 2.8330 *

R-squared 0.3833 Adjusted R-squared 0.3468

F-statistic 10.4971 * No. of observations 323

Dependent variable UBW

Notes: (1) * significant at the 1 percent level ; ** significant at the 5 percent level; and

# significant at the 10 percent level

(2) PE, MK, YMT, TKT, JD, TST, NP and TH denote that the building is located in

Prince Edward, Mongkok, Yau Ma Tei, Tai Kok Tsui, Jordan, Tsim Sha Tsui,

North Point and Tin Hau, respectively. Buildings in the Quarry Bay are taken as

the base.

Table 5: Results of the regression analysis on the high-risk UBWs

Variable Coefficient t-Statistic

Constant -0.1259 -1.0601

AGE 0.0063 2.5381 **

SIZE 0.0031 1.8314 #

UNIT -0.0005 -1.9794 **

ESTATE -0.0624 -1.0709

IO -0.0906 -1.5098

OC -0.0143 -0.1892

MAC -0.0592 -0.6263

PM -0.0458 -1.1087

ACHOOD -0.0727 -1.7848 #

DRYFAC 0.0510 1.1434

PE 0.5056 4.5139 *

MK 0.2591 2.0092 **

YMT 0.0246 0.3760

TKT 0.1963 2.7237 *

JD 0.0214 0.3240

TST 0.0719 0.9211

NP -0.0420 -0.8168

TH 0.0131 0.2128

R-squared 0.3247 Adjusted R-squared 0.2847

F-statistic 8.1208 * No. of observations 323

Dependent variable HRUBW

Notes: * significant at the 1 percent level ; ** significant at the 5 percent level; and

# significant at the 10 percent level

Table 6: Results of the regression analysis on the low-risk UBWs

Variable Coefficient t-Statistic

Constant 1.0794 2.1317 **

AGE 0.0174 1.5921

SIZE 0.0141 2.5706 **

UNIT -0.0041 -3.9112 *

ESTATE 0.0001 0.0004

IO 0.3634 1.4124

OC 0.5602 1.2514

MAC -0.0875 -0.2950

PM -0.1733 -0.8833

ACHOOD -1.3249 -5.8309 *

DRYFAC -0.6392 -2.9957 *

PE 0.4131 1.5097

MK 0.2065 0.7522

YMT 0.7518 2.0296 **

TKT 0.0580 0.1858

JD 0.2162 0.6314

TST 0.5565 1.8036 #

NP 0.8276 3.1375 *

TH 0.7818 1.9120 #

R-squared 0.3312 Adjusted R-squared 0.3292

F-statistic 8.3621 * No. of observations 323

Dependent variable LRUBW

Notes: * significant at the 1 percent level ; ** significant at the 5 percent level; and

# significant at the 10 percent level

1 The Buildings Ordinance and its subsidiary regulations constitute the legal framework for the building control system in Hong Kong, aiming to ensure that certain standards of safety, health, and environmental conditions are attained. The Buildings Department serves as the enforcement agency. In the broadest sense, control of existing buildings involves enforcement against dangerous buildings and UBWs. 2 The objectives of the Building Management Ordinance are to facilitate the incorporation of the owners of flats in buildings, provide for the management of buildings, and deal with matters incidental or connected to them. In addition, the Secretary for Home Affairs is empowered by the Building Management Ordinance to impose a mandatory system of management on buildings that are not managed or not properly managed and thereby pose a risk to its occupants and/or owners (Buildings Department, 2002). 3 A DMC is a legal document containing terms that are binding on all owners of a multi-unit or multi-storey building held in multiple ownership. It clearly sets out the rights and obligations of the owners, tenants and management agents in relation to the control and management of the common parts of a building (Buildings Department, 2001). 4 For details of the BQI project, please refer to Ho et al. (2005). 5 The Home Affairs Department maintains a database of private buildings in Hong Kong that can be accessed at the website: http://www.buildingmgt.gov.hk. 3 Although these low-risk UBWs are tolerated by the government, they are still unlawful because they were constructed without the approval and consent of the Building Authority. These unauthorized structures may have to be removed if the government’s policy on UBWs changes.