The SCSI has recently published a guidance note on how to deal with disputes relating to right to light.

Something that doesn’t crop up too often for the valuation practitioner is the request to assess the diminution in value resulting from the loss of light. A loss of light occurs where an adjoining development would materially diminish the daylight reaching a neighbouring property. This is a timely guidance note, as the economy picks up and with the increase in activity in the construction sector following the financial collapse of 2008.
The Society and the Royal Institute of the Architects of Ireland (RIAI) recently published a joint guidance note on the topic, and recommended best practice. Chartered Surveyors have a role in estimating both the loss of light and the loss in value due to an infringement of a right to light. It was Percy J. Waldram, a Chartered Surveyor and light engineer, who pioneered the study of daylight in the 1920s. The methodology he developed is largely used today for measuring and valuing the loss of daylight, and is known as the Waldram diagram. Essentially, this allows for the value of light from the spherical sky to be represented on a flat piece of paper. The diagram is very useful in calculating the effect of complicated external obstructions. Waldram suggested that the threshold of adequate daylight “for ordinary purposes, comparable with clerical work” was represented by a sky factor of 0.2%. It was this level, he maintained, at which the “average reasonable persons would consistently grumble” – otherwise now known as the grumble point (Chynoweth, 2005).

The calculations will be based on carrying out the measurements twice, to enable the grumble lines to be plotted before and after the construction of the offending obstruction. The completed diagram showing the two grumble lines can then be used to determine whether a loss of light has occurred. Where a loss is identified, the diagram will provide the basis for estimating the diminution in value as a result of light loss. In assessing the compensation for loss of light, it helps to have evidence of the light levels before and after, showing the extent of the loss. If the loss can be augmented by the provision of electric lighting, the capitalised cost might be a sufficient basis for compensation. Indeed, if it could be established that the drop in light would result in the loss of rent then, again, a suitable capitalised factor can be applied. It will of course be important to have comparative evidence of rent levels for a similar property in support of your opinion of the appropriate level of compensation, as there is always the possibility that the matter may be decided by the courts. Indeed, the parties could by agreement resolve the dispute by alternative dispute resolution (ADR) such as conciliation, mediation or arbitration (SCSI Right of Light, 2016).
The reduction in light to a premises was considered in the case of Deakins v Hooking (Irish Planning and Environmental Law Journal, Vol. 2, No. 2). The case concerned a reduction in the access to light to a terraced corner house resulting from an extension to the adjoining property. While the plaintiff had failed to obtain a mandatory injunction while building was in progress, due to uncertainty, and initially was not keen to become involved in a legal aid application, the judge held that a mandatory injunction was justified as the plaintiff had made her complaint known from the outset and her loss was sufficiently serious. The judge also assessed damages in the alternative to take into account the possibility that the mandatory injunction might be lifted on appeal, and he assessed these at £4,500. Significantly, the judge qualified the damages by reference to the benefit of the development to the defendant; the sum awarded represented 15% of the economic value of the extension to the defendant. Where an agreement is reached in a dispute, whether simple or more complex, it is advisable that the agreement should be subject to legal advice.

Know what you’re getting into
The right of light can be a complex area, requiring the participation of other specialist professionals such as architects and solicitors, in addition to surveyors. Before taking an instruction from a client, it is essential that a surveyor is fully conversant with and has an understanding of the nature of the dispute, so that proper advice is provided to the client. The SCSI/RIAI guidance note covers procedures to be followed, and gives a brief summary of the law and background to the legal issues that may be involved.
A right of light, for the purpose of the guidance note, is a private, legally enforceable easement or right to a minimum level of natural daylight illuminated through a “defined aperture”, usually a window opening, whether conferred by express or implied grant, or obtained at common law by a process of long uninterrupted enjoyment known as prescription. The enactment of the Land and Conveyancing Law Reform Act, 2009, however, has the effect of abolishing all easements to light or rights of light, unless registered before 2021, or unless that ‘right’ is given by way of an express grant. The nature of most rights of light in Ireland is that they have to be expressly granted, as the law has held that a person or a building has no automatic right of light. Therefore, in circumstances where a built structure materially affects the quality of the light received, the affected party will be unable to sue to prevent this, unless there is an express grant of a right of light in a legal form. The effect of the 2009 Act is to abolish the creation of easements to light in Ireland in future, which were not registered before 2021. After that date a ‘right of light’ has to be expressly granted by deed.
The Right of Light Guidance Note covers a wide area of this important subject, including the considerations to be taken into account when acting for either the dominant owner or the servient owner. There is a comprehensive index containing referenced articles and definitions, which will greatly assist the practising surveyor.

Irish Planning and Environmental Law Journal, Vol. 2, No. 2.
SCSI. Right of Light. SCSI/RIAI Right of Light Guidance Note, 2016.
Chynoweth, P. Progressing the rights to light debate part III: the grumble point revisited. Structural Survey 2005; 23 (4): 251-264.
Chynoweth, P. Progressing the rights to light debate – Part 1: a review of current practice. Structural Survey 2004; 22 (3): 131-137.
Chynoweth, P. Progressing the rights to light debate. Structural Survey 2009; 27 (1): 7-19.

John C. Elliott FRICS FSCSI MCIArb
Elliott & Fitzgerald Property Consultants & Chartered Surveyors