# RECORD ebefda640bee5302366b339dc1624f32b129581a # TITLE: Property price gradients: the vertical dimension # YEAR: 2011.0 VENUE: nan DOI: 10.1007/s10901-010-9203-8 # AUTHORS: S. Wong; Wing-Chau Kwong; Y. Yau; A. Cheung # PAGES: 13 CANDIDATE TABLE PAGES (1-based): [7, 9] # ABSTRACT: 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. ===== PAGE 1 (score 6, numeric-paren 0, table-words 0, var-words 6) ===== ARTICLE Property price gradients: the vertical dimension S. K. Wong • K. W. Chau • Y. Yau • A. K. C. Cheung Received: 17 December 2008 / Accepted: 15 November 2010 / Published online: 4 December 2010  The Author(s) 2010. This article is published with open access at Springerlink.com Abstract 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 sig- nificant 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. Keywords Housing price  Hedonic model  Floor level  Building height  Price gradient 1 Introduction ‘‘Location, location, location’’ is a famous old saying that teaches us the importance of location in choosing and pricing property. Taken literally, location refers to the geographic position of a building. It has become a major focus in urban economics since Alonso’s (1964) famous work on land rents and location in a monocentric city came out. Nowadays, thanks to advances in technology (e.g., GIS), the concept of location not only refers to the S. K. Wong (&)  K. W. Chau  A. K. C. Cheung Department of Real Estate and Construction, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong e-mail: skwongb@hku.hk Y. Yau Department of Public and Social Administration, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong 123 J Hous and the Built Environ (2011) 26:33–45 DOI 10.1007/s10901-010-9203-8 ===== PAGE 7 (score 15, numeric-paren 0, table-words 3, var-words 7) ===== Pit ¼ b1LRi þ c1FLi þ c2FL2 i þ a0 þ a1AGEi þ a2SIZEi þ a3RDVi þ a4GDVi þ a5DPVi þ a6MTRDi þ a7INDEXi þ eit ð4aÞ The variables used in Eq. 4a are defined in Table 3. Variables like building age, flat size, views, distance to the MTR station, and time factors are control factors.6 Our first focus was on b1, which measures the relative price of a low-rise building to a high-rise building (i.e., a test of Hypothesis 3). We expected its sign to be positive because, as discussed before, living in a dense environment may lead to overcrowding and higher mental and physical health risks. Our second interest lay in the coefficients of floor levels c1 and c2. We added a square term for floor level to cater for any non-linear effect (i.e., a test of Hypothesis 1).7 We expected c1 to be positive and c2 to be negative. We also estimated a more flexible specification for the price—floor relationship by replacing the continuous floor variable with floor dummies FL(j) (see Table 3 for its definition) as the independent variables in the hedonic price model specification: Pit ¼ b1LRi þ X 10 j¼2 cjFL jð Þi þ a0 þ a1AGEi þ a2SIZEi þ a3RDVi þ a4GDVi þ a5DPVi þ a6MTRDi þ a6INDEXi þ eit ð4bÞ The first floor is taken as the base floor level. As such, the coefficients of the floor dummies should be positive and increasing with floor level. To test Hypothesis 2, we relaxed the assumption in Eq. 4a and 4b that the patterns of the floor-level premium are the same for both low-rise and high-rise buildings. We added an interaction term for the low-rise dummy (LR) and floor levels (FL and FL(j)) to Eq. 4a and 4b. The resulting equations were: Table 2 Descriptive statistics of the property transaction data Mean Std. dev. Min Max Telford Gardens (No. of transactions = 807) Property price (HK$mil) 1.66 0.34 0.95 2.69 Age (year) 22.08 1.96 18.00 26.08 Flat size (ft2) 601.42 30.98 392.00 681.00 Floor level 5.33 2.84 1.00 10.00 MTR distance (m) 155.45 55.87 64.35 231.23 Street view (%) 0.17 – – – Podium garden view (%) 0.27 – – – MTR depot view (%) 0.13 – – – Low-rise building (%) 0.75 – – – 6 The base period for the time dummies was January 2000. The base view type for the view dummies is a building view. 7 We tried to add the square terms of AGE and SIZE to the equation, but they were insignificant. Property price gradients 39 123 ===== PAGE 8 (score 12, numeric-paren 0, table-words 3, var-words 6) ===== Pit ¼ b1LRi þ b2LRi  FLi þ b3LRi  FL2 i þ c1FLi þ c2FL2 i þ a0 þ a1AGEi þ a2SIZEi þ a3RDVi þ a4GDVi þ a5DPVi þ a6MTRDi þ a7INDEXi þ eit ð5aÞ Pit ¼ b1LRi þ X 10 j¼2 bjLRi  FL jð Þi þ X 10 j¼2 cjFL jð Þi þ a0 þ a1AGEi þ a2SIZEi þ a3RDVi þ a4GDVi þ a5DPVi þ a6MTRDi þ a7INDEXi þ eit: ð5bÞ If the coefficients of these interactive terms are significant, then that would imply different patterns of the floor-level premium. We shall present and discuss the results in the next section. The statistical software employed is EViews 6. 4 Results The results of the two hedonic price models without interaction terms (i.e., Eq. 4a and 4b) are shown in Columns 1 and 2 of Table 4. The R-squared values of these models were over 85%, indicating that our models explained a great deal of variability in the data. The two models were similarly structured except that Eq. 4a assumed a quadratic floor function and Eq. 4b a flexible step function. For both models, the coefficients of the control variables (except AGE and MTRD) were highly significant with expected signs and comparable Table 3 Definition of the variables Variable Definition Pit The transaction price (in HK$million) of property i at time t LRi A building height dummy that equals 1 when property i is a low-rise and zero when it is a high-rise FLi The floor level of property i FL(j)i A floor dummy that equals 1 when property i is on the jth floor and zero if otherwise (base floor = 1/F) AGEi The building age of property i in months SIZEi The gross floor area of property i in square feet RDVi A view dummy that equals 1 when property i possesses a view facing the road and zero if otherwise GDVi A view dummy that equals 1 when property i possesses a view facing the podium garden and zero if otherwise DPVi A view dummy that equals 1 when property i possesses a view facing the MTR depot and zero if otherwise MTRDi The distance between property i and the MTR station in metres INDEXi A monthly property price index for residential developments published by the Rating and Valuation Department, HKSAR Government (Index = 100 in year 1999) a, b, c and v Coefficients to be estimated eit The error term capturing all unmeasured effects 40 S. K. Wong et al. 123 ===== PAGE 9 (score 17, numeric-paren 0, table-words 4, var-words 2) ===== magnitudes.8 Most importantly, we found the following results regarding floor-level and low-rise premiums: Table 4 Estimation results Eq. 4a Eq. 4b Eq. 5a Eq. 5b Variable Coefficient Coefficient Coefficient Coefficient LR 0.0486b 0.0391b 0.1092a 0.1060b FL 0.1181b – 0.1280b – FL2 -0.0082b – -0.0084b – FL(2) – 0.2460b – 0.2888b FL(3) – 0.2966b – 0.3455b FL(4) – 0.3214b – 0.4023b FL(5) – 0.3345b – 0.3566b FL(6) – 0.3490b – 0.4168b FL(7) – 0.3739b – 0.3993b FL(8) – 0.3691b – 0.4365b FL(9) – 0.3662b – 0.4075b FL(10) – 0.3611b – 0.4680b LR*FL – – -0.0143 – LR*FL2 – – 0.0004 – LR*FL(2) – – – -0.0605 LR*FL(3) – – – -0.0684 LR*FL(4) – – – -0.1117a LR*FL(5) – – – -0.0336 LR*FL(6) – – – -0.0983a LR*FL(7) – – – -0.0326 LR*FL(8) – – – -0.0903 LR*FL(9) – – – -0.0592 LR*FL(10) – – – -0.1452b CONSTANT -2.4929b -2.3789b -2.520b -2.3945b AGE 0.0022 0.0017 0.0023 -0.0017 SIZE 0.0034b 0.0033b 0.0034b 0.0033b RDV -0.0935b -0.0997b -0.0966b -0.1059b GDV 0.0420b 0.0470b 0.0415b 0.0436b DPV -0.0817b -0.0839b -0.0816b -0.0810b MTRD -2.68 9 10-5 -9.96 9 10-5 -2.13 9 10-5 -8.35 9 10-5 INDEX 0.0198b 0.0199b 0.0198b 0.0199b R-squared 0.8520 0.8671 0.8532 0.8698 Adj. R-squared 0.8501 0.8642 0.8510 0.8655 We employed White’s standard errors to adjust for heteroskedasticity a Significant at the 5% level b Significant at the 1% level 8 The insignificance of AGE and MTRD was probably due to low data variations. All buildings in the residential estate were built between 1980 and 1982 and were within 250 m of the subway station. Property price gradients 41 123 ===== PAGE 10 (score 8, numeric-paren 0, table-words 1, var-words 6) ===== Hypothesis 1 maintains that floor-level premiums are constant across different floor levels. However, in Eq. 4a, both c1 and c2 were significant at the 1% level with opposite signs. This suggested that the floor-level premium diminishes as floor level increases, hence rejecting Hypothesis 1. Since the quadratic floor function is rather restrictive, Eq. 4b provided a flexible step function for estimating floor-level premiums. Both the results of the step and quadratic functions are plotted in Fig. 2. For the step function, we found a drastic jump in property prices from the 1st to the 2nd floor (about 15% of a property’s price), which implied a great difference in perceived environmental quality (e.g., noise, security issues) between the first two floors. The premiums of the other floors appeared more or less the same, but a re-estimation of Eq. 4a without the first floor still showed a slightly diminishing pattern (with c1 = 0.0505 and c2 = -0.0031, both significant at the 1% level). Therefore, the hypothesis that the floor price gradient is linear was rejected as far as the low floor zone was concerned. A non-linear gradient likely resulted from vari- ations in environmental quality along the vertical dimension. Hypothesis 3 maintains that low-rise buildings do not command a premium or discount over high-rise buildings. However, in both Eq. 4a and 4b, the low-rise premium (b1) was consistently positive and significant at the 1% level, suggesting that units in taller (and thus, denser) buildings were sold at a discount to units in shorter buildings, ceteris paribus. The estimated low-rise premiums were HK$48,584 in Eq. 4a and HK$39,076 in Eq. 4b, representing about 2–3% of the mean transaction price in the sample. These results rejected the constant density hypothesis and confirmed that there was a greater premium for shorter buildings than for taller ones. The premium can be attributed to a lower population density in the common areas of shorter buildings, as elaborated on in Sect. 2. Next, we estimated Eq. 5a and 5b to test if the pattern of the floor-level premiums was constant across buildings of different heights, as maintained by Hypothesis 2. The regression results of Eq. 5a and 5b are shown in Columns 3 and 4 of Table 4. Central to these equations are the interaction of terms LR with the floor levels. Both interaction terms in Eq. 5a and most of the interaction terms in Eq. 5b, however, were insignificant. There was no evidence to support the ‘‘relative’’ logic that floor-level premiums varied with buildings of different heights. Hence, Hypothesis 2 was not rejected. 1.5 1.6 1.7 1.8 1.9 2.0 2.1 1 2 3 4 5 6 7 8 9 10 Floor level Price of a notional property (HK$mil) Quadratic function Step function Fig. 2 The relationship between floor levels and property prices 42 S. K. Wong et al. 123