32 In Parsonage v Ku-ring-gai [2004] NSWLEC 347, Roseth SC dealt with the planning principles concerning the impact on solar access of neighbours. The relevant paragraphs of the decision read:
6. The Australia-wide resource document for residential development, AMCORD , suggests that a development should not reduce the sunlight received by the north-facing windows of living areas of neighbouring properties to less than 3 hours between 9am and 5pm at the winter solstice. The NSW-specific Residential Flat Design Code , which applies only to apartment buildings of three storeys and over, recommends 3 hours of sunlight to the living rooms and private open spaces of 70% of apartments between 9am and 3pm, reducing it to 2 hours in dense urban areas. The Code does not specifically deal with the impact on sunlight received by neighbouring buildings, though one may assume that the same criteria apply. Where local controls contain numerical guidelines, they usually require the retention for neighbouring properties of 3-4 hours of sunlight on living room windows and private open spaces between 9am and 3pm at the winter solstice.
7. The Court must, of course, take into account whatever guidelines are relevant to an application. However, numerical guidelines should be applied with a great deal of judgment. Consider a dwelling that now receives sunlight all day. Taking away that sunlight from 9am till noon would satisfy most guidelines; and yet the occupants of such a dwelling are likely to perceive it as a devastating impact on their dwelling's amenity. The other side of the coin is that the impact on a neighbour's sunlight must be assessed in the context of the reasonable development expectations of the proposal and the constraints imposed by the topography and the subdivision pattern. Preserving 3 hours of sunlight on a neighbouring site may require an unreasonable reduction in the development potential of the proposal.
8. Numerical guidelines dealing with the hours of sunlight on a window or open space usually leave open the question what proportion of the window or open space should be in sunlight, and whether the sunlight should be measured at floor, table or a standing person's eye level. Numerical guidelines should therefore be applied with the following principles in mind, where relevant:
- The ease with which sunlight access can be protected is inversely proportional to the density of development. At low densities, there is a reasonable expectation that a dwelling and some of its open space will retain its existing sunlight. (However, even at low densities there are sites and buildings that are highly vulnerable to being overshadowed.) At higher densities sunlight is harder to protect and the claim to retain it is not as strong.
- The amount of sunlight lost should be taken into account, as well as the amount of sunlight retained.
- Overshadowing arising out of poor design is not acceptable, even if it satisfies numerical guidelines. The poor quality of a proposal's design may be demonstrated by a more sensitive design that achieves the same amenity without substantial additional cost, while reducing the impact on neighbours.
- To be assessed as being in sunlight, the sun should strike a vertical surface at a horizontal angle of 22.50 or more. (This is because sunlight at extremely oblique angles has little effect.) For a window, door or glass wall to be assessed as being in sunlight, half of its area should be in sunlight. For private open space to be assessed as being in sunlight, either half its area or a useable strip adjoining the living area should be in sunlight, depending on the size of the space. The amount of sunlight on private open space should be measured at ground level.
- Overshadowing by fences, roof overhangs and changes in level should be taken into consideration. Overshadowing by vegetation should be ignored, except that vegetation may be taken into account in a qualitative way, in particular dense hedges that appear like a solid fence.
- In areas undergoing change, the impact on what is likely to be built on adjoining sites should be considered as well as the existing development.