Sun study
A sun study (Norwegian: solstudie) is an analysis of how sunlight and shadow fall on and around a building project through the day and through the year. It shows how much sun outdoor areas, façades and neighbouring properties receive on selected dates and times, and it is used to document that a project provides good enough sunlight conditions, and that it does not cast unacceptable shadow on its surroundings. The sun study is a standard attachment in most zoning cases for housing and urban development projects.
The analysis starts from the path of the sun, which is given by latitude and date, and a 3D model of existing and planned buildings and terrain. The result is shown as shadow diagrams for fixed reference times. Common Norwegian practice is to show the spring and autumn equinox (around 21 March and 23 September) and the summer solstice (21 June), often at 09:00, 12:00, 15:00 and 18:00, because these dates represent typical conditions through the year. Many municipalities set specific requirements in the zoning provisions, for example that a certain share of the outdoor amenity space must have at least five hours of sun at the equinox.
Sunlight conditions are closely linked to several other assessments in a project. Taller buildings from densification cast more shadow on the neighbours, and the sun study is often decisive for how high you can build. It is read together with sightlines and with the requirements for daylight inside the home under TEK17, which regulates how much daylight a habitable room must have. A sun study of the outdoor area and a daylight calculation indoors are two different analyses, but both concern light conditions and are often assessed at the same time. For an architect or developer, an early sun study is a useful tool in the feasibility study: it quickly reveals whether a desired height and position give acceptable conditions, before much design time has been spent.
In Placepoint you can use the shadow tool in 3D to see how shadow falls from buildings at a chosen time, as a quick starting point for assessing sunlight conditions before a full sun study is prepared.
How it looks in Placepoint
In Placepoint you find this in 3D-Designer:
From Placepoint's glossary: Sun study
More information: DiBK: TEK17 § 8-3 Uteoppholdsareal, Lovdata: TEK17 § 13-7 Lys og utsyn
English: Sun/shadow study (solar access analysis).
Frequently asked questions
What is a sun study?
A sun study is an analysis of how sunlight and shadow fall on and around a building project through the day and through the year. It documents that the project provides good enough sunlight conditions and does not cast unacceptable shadow on the neighbours, and it is a standard attachment in zoning cases.
Which dates and times are used in a sun study?
Norwegian practice is to show the spring and autumn equinox (around 21 March and 23 September) and the summer solstice (21 June), often at 09:00, 12:00, 15:00 and 18:00. These represent typical sunlight conditions through the year.
What is the difference between a sun study and a daylight calculation?
A sun study assesses sunlight and shadow on outdoor areas and façades. A daylight calculation under TEK17 assesses how much daylight habitable rooms receive inside the home. Both concern light conditions and are often done at the same time, but they are different analyses.
Why is a sun study important in densification?
Because taller buildings from densification cast more shadow on the neighbours. The sun study is often decisive for how high you can build, and many municipalities set requirements in the zoning provisions for the minimum number of sunlight hours on the outdoor amenity space.