Illumination of monuments and historic facades

By: Secom
1 de June, 2021
Reading time: 13 min

The key to lighting historic facades and monuments is highlighting examples of historic heritage, making them stand out and drawing the eye to their more impressive architectural features. It is for that reason that operational and installation procedures are subject to such strict rules.

This article addresses...


Lighting projects require research and analysis: when it is time to carry out the work, a multidisciplinary group needs to be coordinated and tests and modifications must be made.

1. Factors to bear in mind when lighting a facade

When illuminating a city, we can divide the task into three distinct types of lighting: urban, commercial and ornamental. It is the third type that comes into play when illuminating the facades of monuments. This work takes into account a number of decisions with regard to the sources of light, the distribution of luminaires and the colour temperature, among others.

Other factors to consider in these projects are the planimetry, the possibility of designing tailor-made luminaires, the details of the construction, the data and technical information, the calculations and approximate budget.


The type of aesthetic needs

LED lighting on historical building facades is not subject to the same criteria as urban lighting. For instance, to a certain degree it is possible to emit light to the upper half of the building, providing that the lights meet the established laws. Therefore, it is necessary to design a solution with special care in order to avoid excessive light.

The lights must be out of sight and also easy to dismantle, in case it is necessary to restore the monument back to its original state. As well as that, using different light temperatures is recommendable, sometimes warm and others cold, depending on the desired effect.

The shape and contrast of the building

Thanks to LED technology, adaptable lighting of facades and monuments is achievable. This allows for solutions that are adequate, efficient and aesthetic, which nevertheless present a challenge of both creativity and professionalism for those responsible for the design.


LED luminaires contribute to the sustainability of monumental lighting projects and, when compared with conventional lights, can lead to energy savings of 85%.

Municipal regulations

Among the references to this type of work in Spanish legislation is one that is found in article 19.3 of the Law of 25 June, 16/1985 on Spanish Historic Heritage (artículo 19.3 de la Ley 16/1985, de 25 de junio, de Patrimonio Histórico Español). On the basis of this law, the laying of cables, antennas or advertising on facades or roofs is prohibited.

Another important law the Energy Efficiency Regulation on outdoor lighting installations and Technical Instructions EA-01-07 (RD 1890/2008) (Reglamento de Eficiencia Energética en instalaciones de alumbrado exterior e Instrucciones Técnicas EA-01-07 (RD 1890/2008) and Law 34/2007 on air quality and the protection of the atmosphere (Ley 34/2007 de calidad del aire y protección de la atmósfera) where the definition of light pollution can be found.

These projects are subject to oversight

In order to guarantee control over the illumination, a diagnostic evaluation is advisable, one which details the installation of the lighting and includes an infographic about the results.

Normally, in the case of projects for monumental buildings a multidisciplinary team is set up, one consisting of managers, town planners, as well as experts in the history of art, engineering and lighting design. In fact, many cities rely on lighting plans that include control criteria.


The necessary power

When carrying out a lighting study, it is necessary to avoid lighting the facade in question to an excessive degree. For that reason, employing LED luminaires is recommendable, due to their energy efficiency and reduced consumption, as well as the application of control systems that allow maximal efficiency.

As a point of reference, in Spain 1kWh is the equivalent of emitting 430g of CO2 into the atmosphere. Therefore, a small installation with around 5kW, which remains turned on for around 1000 hours annually, has an approximate emission of 2 tonnes of CO2.


2. Recommendations for the best lighting results

A successful monumental lighting project requires a report, a virtual simulation of the end result and an estimate of the final cost of the project.

Project planned in optimum phases. Research process

The execution plan must include a definitive illumination plan, another plan that details the electrical installation, the technical specifications, a health and safety evaluation, and an estimated budget. In turn, on completion of the work it is necessary to hand in the as-built drawings, a professional photographic report, the maintenance plan and other documents detailed in RD 1890/2008.

Colour control RGBW luminaires

RGBW luminaires are improvements on RGB luminaires. Basically, they include a diode of white light that can be either cold or warm white. This is very important for classical facades.

In general, using this type of luminaire leads to a wide chromatic spectrum within the visible light. The colour temperature depends on the building materials, although it is possible to capture the colours desired. The materials influence the colour tones and the vibrancy produced by the beam of light on these materials.


Energy savings from LED

LED technology allows a great quantity of energy to be saved in the installations for historic facades and monuments, which require an important number of lights. It is adaptable, making it possible to build the right light intensity distribution curve for each situation.

Lighting control systems

These are used to maintain control of energy efficiency and, also, to create different effects and atmospheres. It is possible to regulate and control them with cutting-edge technology.

Protection against overcurrent

The surge protectors that are inbuilt in the equipment used for these projects protect the electronics of the luminaire, as well as the most delicate electronic parts, from power surges.

In short, lighting historic facades and monuments requires a large, in-depth project. One must always follow a series of guidelines in order to highlight the architectural and aesthetic value of the building, while combining that goal with those that work towards guaranteeing sustainability and energy efficiency.


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