Elsevier

Energy Policy

Volume 67, April 2014, Pages 82-86
Energy Policy

Efficient lighting in buildings: The lack of legislation in Portugal

https://doi.org/10.1016/j.enpol.2013.11.031Get rights and content

Highlights

  • In the Portuguese legislation there are no rules concerning the use of daylight.

  • Lack of specific regulation limiting power density of artificial lighting.

  • Revision of Portuguese building energy systems regulation.

  • Some proposals for future legislation.

  • Improvement of Portuguese buildings promoting energy efficiency.

Abstract

The behavior of building designers is conditioned by the existing legislation and regulations in the national context in which they operate. However, in the Portuguese legislation there are no rules concerning the use of daylight, and therefore, designers are not stimulated to adopt solutions that make use of the existing potential of sunlight availability. In the same way, it is difficult to understand the lack of specific regulation, with quantified targets, limiting power density of artificial lighting installed inside buildings. The present opportunity, generated by the need to carry out the revision of Portuguese building energy systems regulation, should be used to fill the existing gap in national legislation regarding those matters. In this paper the authors present some proposals for future legislation that will have as central purpose the utilization of efficient lighting systems and the promotion of architectural solutions that optimize the use of daylighting. It is possible, and desirable, to add new directives to national legislation that contribute to the improvement of Portuguese buildings, characterized by its good performance in terms of daylight availability, and at the same time, increasing the energy efficiency and reducing the energy consumption of lighting systems installed in those buildings.

Introduction

One of the sectors with higher preponderance on Portuguese energy consumption is the building sector, both in its residential and commercial components, as can be seen in the statistics of energy consumption published over past years. This is the case of the year 2009, more recent consolidated data, where energy consumption in buildings is 30% of total national consumption in final energy (DGEG, 2010) and approximately 60% of national electricity consumption (INE, 2011). A substantial portion of that energy consumption is electrical energy used to generate artificial lighting in commercial buildings. With this present concern, and to illustrate numerically the significance of lighting in energy consumption, it was possible to find a value for the rate of lighting energy consumption in the total electricity consumption of commercial buildings from the data published in the synthesis report “Caracterização Energética do Sector de Serviços” (DGE, 1994). Thus, energy consumption for lighting could be estimated at 29% of the total electricity consumption in commercial buildings for the year 1991. We present this value, although with reluctance for its antiquity, for the purpose of illustration of the difficulty in making an informed characterization with more recent data as it should be. The 29% figure is in line with the statistics for the nearby country of Spain that shows that for the year of 2010, 31.4% of electricity was consumed in lighting in commercial buildings (IDEA, 2011). Despite this difficulty, one can say without hesitation that lighting is one major consumer of electricity when analyzing energy consumption in the buildings sector. With reference to the above data, we can see the relevance of energy consumption of lighting and thus the available potential for energy savings. It is possible and desirable to add, in the new Portuguese law, directives that contribute to the improvement of buildings that are constructed in Portugal, characterized by its good performance in terms of availability of daylight, and at the same time, increasing the energy efficiency of lighting systems installed in those buildings.

Section snippets

Reference of the EU

Reducing levels of consumption for lighting in the building sector should be a concern for legislators taking them to put into law the necessary regulations to encourage the best available quality design, and construction, of residential and commercial buildings so they can make better use of daylight without forgetting or harming the thermal characteristics of those buildings. This concern is in consonance with what was defined as purpose and objective in various plans and programs produced

Portuguese legislation and European standards

As can be seen by the EPBD, the characteristics of positioning, orientation and construction of buildings are very important for its energy performance, and for this reason a field of action that the legislators should not forget. However, daylighting is almost nonexisting in Portuguese legislation. It shows a nearly complete regulatory uncertainty about the design and construction of buildings with the purpose of maximizing the use of daylight, and at the same time, increasing the visual

Situation in other countries

Traditionally, the legislations of several countries determined a minimum value for the area of openings in facades, typically 10% of the respective floor area. It is the case of Portuguese legislation for residential buildings. However, the major concern that originated with this measure was to promote the public health of the occupants of the buildings and, to a lesser degree, to promote the use of natural light in those buildings. The WFR of 10% is insufficient if we aim to partially replace

Efficient lighting, proposals

From the overall results of the analysis of the national situation with the lessons learned from the study of solutions in the legislation of other countries, we can conclude that it is possible and desirable to join some of the determinations and guidelines to the Portuguese law that are essential to ensure the construction of better buildings in our country, characterized by their optimum performance in terms of available light, natural and artificial, and by the efficiency of all the

Conclusions

Lighting in buildings has a relevance that, besides being intuitive, the share of energy consumption responsible can be recognized from the few known data. The few allusions to lighting in the legislation are, in most cases, statements with good intentions but without implementation of effective rules. This lack of specific regulations is not common in other countries. As we can see in the brief analysis of legislations of other countries presented in this paper, lighting is very much present

References (20)

  • ASHRAE, American Society of Heating, Refrigerating and Air-Conditioning Engineers, 2011. Advanced Energy Design Guide...
  • ASHRAE90.1, 2007. American National Standards Institute, ANSI/ASHRAE/IESNA Standard 90.1-2007. Energy Standard for...
  • BCA2009, 2009. Department of Innovation, Industry, Science and Research. Building Code of Australia 2009, Building...
  • BR2000, 2010. The Stationery Office. The Building Regulations 2000, AD L2 Conservation of Fuel and Power in Buildings...
  • CTE, 2009. Ministerio de Vivienda. Código Técnico de la Edificación, DB-HE: Ahorro de Energia. Spanish Legislation,...
  • DGE, Direcção Geral de Energia – Ministério da Economia, 1994. Caracterização Energética do Sector de Serviços....
  • DGEG, Direcção Geral de Energia e Geologia – Ministério da Economia, 2010. Indicadores Energéticos – Quadro III...
  • EN15193, 2007. CEN – European Committee for Standardization. EN15193: Energy Performance of Buildings – Energy...
  • EPBD

    Parlamento Europeu e Conselho da União Europeia, Directiva 2010/31/UE de 19 de Maio de 2010 relativa ao desempenho energético de edifícios

    J. Off. União Eur.

    (2010)
  • FR10CFR434, 2000. Department of Energy. Federal Register, 10 CFR Part 434, Energy Code for New Federal Commercial and...
There are more references available in the full text version of this article.

Cited by (5)

  • Enhancing the passive design of buildings: A mixed integer non-linear programming approach for the selection of building materials and construction building systems

    2021, Energy Reports
    Citation Excerpt :

    In hot climates, heat gain imposes a major load on the HVAC systems, which need to maintain cool temperatures to compensate for the heat flows indoor via the exterior walls, roof, floors, ceiling, and windows. The building’s lighting generates internal heat that can raise the indoor temperature to unpleasant levels (Almeida and Martins, 2014). Typically, heat gain across a building’s envelope occurs due to convection and solar heat (Tao et al., 2020).

  • Indoor lighting techniques: An overview of evolution and new trends for energy saving

    2017, Energy and Buildings
    Citation Excerpt :

    According to the same analysis, the LED market share in the office segment is estimated at approximately 2% and expected to grow to around 30% by 2016 and approximately 52% by 2020 [66]. Lighting is very much present not only in terms of objectives, but with mandatory targets and quantified measures both for artificial lighting as well as for day-lighting [74]. These determinations are manifested mainly by limiting the consumption of electricity for lighting and by promoting the use of day-lighting.

View full text