Property price gradients: The vertical dimension

This is an empirical study on the pricing of two vertical property attributes: floor level and building height. Floor level is the vertical location of a unit in a multi-storey building; the extra price paid for a higher floor level is labelled a floor-level premium. Previous hedonic price studies unequivocally showed that the floor-level premium is positive, but they were silent on whether its magnitude varies with floor levels and with buildings of different heights. Indeed, building height is a feature of a building, not its constituent units, so it is not clear whether building height alone should affect the units' prices. Based on a sample of highly homogeneous housing units in buildings of varying heights, we found that (1) the floor-level premium was not constant, but diminished as floor level increases; (2) there was no significant difference in the pattern of the floor-level premium between high-rise and low-rise buildings; and (3) there was a positive and significant premium for units in low-rise buildings over those in high-rise ones. These findings can help developers determine the optimal height and shape of their development. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Floor-level premiums in high-rise and low-rise buildings

This paper examines a unique feature of multi-storey buildings – floor-level premiums. Floor-level premiums refer to the price paid for the vertical location of a flat, measured by its floor level. Previous hedonic price studies unequivocally showed that floor-level premiums are positive. However, they were often based on the assumptions that floorlevel premiums are constant 1) across different floor levels within the same building and/or 2) across different buildings given the same floor level. This second assumption is particularly interesting because it begs the question of whether the same premium is paid for high-rise and low-rise buildings. For instance, do we pay the same for the 5th floor of a low-rise building and that of a high-rise building? Based on a sample of highly homogeneous buildings (except for their heights), we found that floor-level premiums were not constant but diminishing with respect to floor levels. Moreover, there was no significant difference in the pattern of floor-level premiums between high-rise and lowrise buildings. Finally, there was a positive and significant premium for shorter buildings over taller buildings.published_or_final_versio

Comparative study of Building Performance Assessment Schemes in Hong Kong

Having access to information is essential when one needs to make a decision to buy property or renovate a building. However, information concerning the health, safety, and environmental performance of buildings is not always readily available. This creates a need for building performance assessment tools. This paper aims to compare the building performance assessment schemes available for use in Hong Kong, namely The Hong Kong Building Environment Assessment Method (HK-BEAM), The Intelligent Building Index (IBI), The Building Quality Index (BQI), and The Comprehensive Environmental Performance Assessment Scheme for Buildings (CEPAS). Their similarities and differences are pinpointed and discussed in detail. The findings of this study will serve as a guide for practitioners to decide on the schemes that best suit their purposes.postprin

The effect of SARS on the price of re-entrants in multi-storey apartment buildings

Natural lighting and ventilation have long been a primary consideration in building design, particularly for those high-rise and densely packed apartment blocks where mechanical ventilation is normally secondary. In Hong Kong, there are prescriptive legal requirements governing the provision of natural lighting and ventilation in private buildings. This, coupled with developers’ profit-maximizing incentives, often gives rise to re-entrant designs commonly found in apartment buildings in Hong Kong. This paper aims to study the economic impacts of the disposition of re-entrants on property prices with reference to the revelation of the chimney effect of re-entrants after the occurrence of the mass community outbreak of Severe Acute Respiratory Disease (SARS) in Amoy Gardens in 2003. In this study, we use a hedonic pricing model to examine whether flats designed with a re-entrant is sold at a different price than those without a re-entrant. We draw a sample of property transactions from a popular single residential development with variations in re-entrant designs. A total of 357 transactions were collected, of which 90 were transacted after the SARS event. The model is capable to monitor any significance changes in the premium of re-entrant and its relationship with floor level before and after SARS. Based on the hedonic pricing analysis, we found that the preference for re-entrants is floor-dependent. Before SARS, homebuyers were not fond of re-entrants on low floor levels, but they were willing to pay more for re-entrants as the floor level increases. Yet, the outbreak of SARS did not significantly change their preferences for re-entrants. The market is capable to capitalize the building design into property prices. Developers and designs should improve their building design to meet the ever changing needs of the market. This paper provides an empirical framework to examine how homebuyers price a particular design feature using property transaction data.published_or_final_versio

An empirical study on the neighbourhood effect of refurbishment

An important portion of property value comes from property location, which is a function of the quality of surrounding environment (e.g. external views). In a congested living environment like Hong Kong, it is difficult, if not impossible, to have a view unobstructed by buildings. As such, the quality of views is dependent upon the aesthetic quality of surrounding buildings. It is likely that poorly maintained buildings will emit negative visual effects to their immediate neighbourhood. Refurbishing these poor buildings should, therefore, reduce or even counter this negative externality. This study aims to empirically identify the effect of refurbishment on the prices of neighbourhood properties based on an analysis of panel data in Hong Kong. The data consists of property transactions in a large housing estate located in Pokfulam. This estate was chosen because its surrounding buildings underwent refurbishment in 1998. Results show that the refurbishment brought a significant increase in the price of properties facing the refurbished buildings, keeping other things constant. Given the aging building problem in most urban areas, the results pose significant practical implications on building refurbishment and urban rehabilitation as a whole. Developers or property owners may be lured to invest in the refurbishment of adjacent dilapidated properties with a view to a value enhancement of their own properties.published_or_final_versio

Familial adenomatous patients with desmoid tumours show increased expression of miR-34a in serum and high levels in tumours

Familial adenomatous polyposis (FAP) is rare affecting 1 in 10,000 people and a subset (10%) are at risk of myofibroblastic desmoid tumours (DTs) after colectomy to prevent cancer. DTs are a major cause of morbidity and mortality. The absence of markers to monitor progression and a lack of treatment options are significant limitations to clinical management. We investigated microRNAs (miRNA) levels in DTs and serum using expression array analysis on two independent cohorts of FAP patients (total, n=24). Each comprised equal numbers of patients who had formed DTs (cases) and those who had not (controls). All controls had absence of DTs confirmed by clinical and radiological assessment over at least three years post- colectomy. Technical qPCR validation was performed using an expanded cohort (29 FAP patients; 16 cases and 13 controls). The most significant elevated serum miRNA marker of DTs was miR-34a-5p and in-situ hybridisation (ISH) showed most DTs analysed (5/6) expressed miRNA-34a-5p. Exome sequencing of tumour and matched germline DNA did not detect mutations within the miR-34a-5p transcript sites or 3'-UTR of target genes that would alter functional miRNA activity. In conclusion, miR-34a-5p is a potential circulatory marker and therapy target. A large prospective world-wide multi-centre study is now warranted

Torus equivariant K-stability

It is conjectured that to test the K-polystability of a polarised variety it is enough to consider test-configurations which are equivariant with respect to a torus in the automorphism group. We prove partial results towards this conjecture. We also show that it would give a new proof of the K-polystability of constant scalar curvature polarised manifolds

Nasopharyngeal carcinoma: time lapse before diagnosis and treatment

This is a descriptive study of 168 patients with nasopharyngeal carcinoma who were referred to public oncology departments for primary treatment between July and September 1996. The mean duration from the onset of the symptoms to histological diagnosis was 5.0 months; the duration ranged from 6.1 months (for patients presenting with nasal symptoms) to 1.8 months (for those with cranial nerve dysfunction). The mean period between the onset of symptoms and the seeking of medical advice was 2.9months. For 54% of the patients, there was a further delay of up to 2.4 months between the initial medical consultation and referral to the appropriate specialist. The majority (84%) of patients attended public institutions for histological confirmation. The mean total time taken from the onset of symptoms to the commencement of radiotherapy was 6.5 months (range, 1.3-74.0 months)---45% of the delay was attributed to the patient, 20% to initial consultations, 14% to diagnostic arrangement, and 21% to preparation for radiotherapy. Concerted efforts are needed to minimise further the time between the onset of symptoms and treatment. A substantial reduction in this delay can be achieved if both public and primary care doctors were made more aware of the significance of relevant symptoms.published_or_final_versio

Numerical Hermitian Yang-Mills Connections and Kahler Cone Substructure

We further develop the numerical algorithm for computing the gauge connection of slope-stable holomorphic vector bundles on Calabi-Yau manifolds. In particular, recent work on the generalized Donaldson algorithm is extended to bundles with Kahler cone substructure on manifolds with h^{1,1}>1. Since the computation depends only on a one-dimensional ray in the Kahler moduli space, it can probe slope-stability regardless of the size of h^{1,1}. Suitably normalized error measures are introduced to quantitatively compare results for different directions in Kahler moduli space. A significantly improved numerical integration procedure based on adaptive refinements is described and implemented. Finally, an efficient numerical check is proposed for determining whether or not a vector bundle is slope-stable without computing its full connection.Comment: 38 pages, 10 figure

Kahler-Einstein metrics emerging from free fermions and statistical mechanics

We propose a statistical mechanical derivation of Kahler-Einstein metrics, i.e. solutions to Einstein's vacuum field equations in Euclidean signature (with a cosmological constant) on a compact Kahler manifold X. The microscopic theory is given by a canonical free fermion gas on X whose one-particle states are pluricanonical holomorphic sections on X (coinciding with higher spin states in the case of a Riemann surface). A heuristic, but hopefully physically illuminating, argument for the convergence in the thermodynamical (large N) limit is given, based on a recent mathematically rigorous result about exponentially small fluctuations of Slater determinants. Relations to effective bosonization and the Yau-Tian-Donaldson program in Kahler geometry are pointed out. The precise mathematical details will be investigated elsewhere.Comment: v1: 22 pages v2: 25 pages. The relation to quantum gravity has been further developed by working over the moduli space of all complex structures. Relations to Donaldson's program pointed out. References adde