This paper seeks to extend the definition of a sub-centre beyond the usual definition as a place with significantly larger employment density that has an effect on the overall employment density of the nearby locations. Together with the previous conditions, it is suggested that it is necessary to include another which represents a structural element of an urban sub-system within the metropolitan configuration—that is, a place with intense spatial interaction with its hinterland. Therefore, a metropolitan area can be seen as one comprising urban sub-systems characterised by greater or lesser polycentrism. In this paper, a ‘bottom—up’ methodology based on commuter flows is proposed in order to detect metropolitan sub-centres. Using empirical data from the Metropolitan Region of Barcelona, the proposed methodology is tested, comparing its results with those of other commonly used methodologies (cut-offs, parametric and non-parametric models). The results suggest that the proposed methodology permits optimising the sub-centre delimitation process.

In the literature, there is extensive, although in some cases inconclusive, evidence on the impact of Energy Performance Certificates (EPC) on housing prices. Nonetheless, the question of whether such an impact is homogenous across residential segments remains highly unexplored. This paper addresses this latter issue utilizing multifamily listing data in metropolitan Barcelona. In doing so, first the entire sample is analyzed using a hedonic model. Second, the sample is split on the basis of a multivariate segmentation. Finally, separated hedonic models are specified again. The results suggest that in general, there is a modest impact of EPC ratings on listing prices, nonetheless it is not homogeneous across housing segments: (1) for the most modern apartments, with state-of-the-art features and active environmental comfort, energy ratings seem to play a null role in the formation of prices; (2) conversely, for the cheapest apartments, apartments boasting the most basic features, and apartments located in low-income areas, the "brown discount" is enormously significant, potentially depreciating the equity of those who have the least resources to carry out an energy retrofit. These results have implications for the assessment of the EPBD and its Spanish transposition, since a very well-intentioned environmental policy could have potentially harmful social repercussions in the absence of corrective measures.Commission saw the EPC scheme as "a power tool to create a demand-driven market for energy efficient buildings (p. 5) [6].Among all the real estate markets, the residential one is a special case since, due to the size of its stock, it consumes much more energy than commercial properties [7]. In the literature, there is extensive, yet in some case inconclusive, evidence regarding the existence of market premiums for efficient homes. According to the studies reviewed in the next section, home selling prices can vary up to 30.5% (for rating A, the most efficient one, in relation to rating G as the most inefficient) in the Danish case [8] or as little as 5% (A/G) in the case of the Irish renting market [9]. However, there is evidence suggesting that EPC labels do not play any role in price discrimination in the Oslo market [1]. Differences in climate and energy costs in relation to home prices and, perhaps, environmental concerns may be behind such divergences. As such, there are no reasons to believe that the impact of EPC labels is stationary across housing segments within the same city, where household budgets, personal tastes, and priorities, as well as home attributes and prices also vary in a significant manner. As a matter of fact, in the office market, there is evidence suggesting that "green labels" are contingent to characteristics of buildings in the determination of prices [10].The aim of this paper is to test whether the impact of EPC ratings on housing prices is the same in different market segments within a city. This analysis is relevant since the identification of divergent impacts may help to orien...

Energy performance certificates (EPCs) are important tools aimed at improving buildings’ energy performance. They play a central role in the context of the Energy Performance of Buildings Directive (EPBD) which asks member states (MS) to take the necessary measures to establish a complete certification system. In this study, an application of the hedonic price method (HPM) assessing the effect of energy labels derived from the EPC on real estate market value is presented. The estimation methodology was applied to two European cities characterized by different climate conditions. The analysis was based on two datasets of listing prices referring to multi-family residential markets in Turin (Italy) and Barcelona (Spain). Four models for each dataset were applied to capture the marginal price of green attributes, but also to control for the spatial autocorrelation among values. The findings showed how the EPC has been applied in the two countries and how it has influenced the real estate market. Turin’s buyers pay more attention to the EPC label, while in Barcelona, they value much more single characteristics, such as air conditioning and a swimming pool, considered popular attributes among contemporary buildings in this climate zone. From the results, it is possible to deduce that the implementation of the EPC schemes is still irregular in EU countries and must be strengthened through a standardized rating model.

In most countries, energy efficiency at the residential level has been largely delegated to the dynamics of realestate markets after setting a minimum level. This regulatory definition is in certain cases supplemented by energy performance certificates, such as in the case of the European Union. This approach is based on the understanding that avoided energy-consumption costs positively affect the willingness to pay for them, thus leading to higher prices capable of offsetting production costs and thereby encouraging developers. The case of the private housing market in Santiago de Chile was selected as a reference for a developing country in which energy performance certificates, although they exist as an instrument, are not required to be applied in property transactions. However, unlike most of the research performed in developed countries, it is difficult to analyse price formation using methods based on observed preferences in areas in which there are few energy-certified buildings. Using the technique of contingent valuation, such as the method based on stated preferences, enables one to overcome this difficulty. This article investigates willingness to pay for improvements in the energy efficiency of buyers for new homes based on a representative investment/operation cost analysis. This approach has been addressed to open the debate on the convenience of modify the national construction code and rethink the energy certification scheme as well as an exploratory study to undercover further research lines to support the aforementioned debate. The results suggests that there is a number of potential home buyers ready to pay for energy efficiency when they are informed on the cost savings associated to structural modifications and the cost of providing such improvements and such willingness to pay is not monolithic across the respondents, but seems to be influenced by the education level plausibly associated to the purchase power.

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