Guide

What does west-facing mean — in sun hours?

"West-facing balcony with great sun" says the listing. But west-facing is a direction, not a number — and what the direction can actually give changes drastically through the year. Below is the ceiling: the most a completely free west wall can get in Oslo, month by month, computed with the same solar-position model as our reports. How much of it your wall keeps is decided by the neighbouring buildings and the trees — and that is what the report measures.

The short answer

West-facing means afternoon and evening sun, and never morning sun: the sun first comes around to a west wall just after solar noon — around 13:20 in summer, around 12:15 in winter — and stays on it until it sets. At midsummer that is a lot: the sun is on the wall from early afternoon until it sets in the northwest at 22:42, up to nine and a half hours. At the equinoxes the ceiling is about six hours. And on 21 December it is under three — because the sun sets at 15:10, in the southwest, without ever properly reaching west at all.

The ceiling, month by month

These figures are the most a west-facing wall in Oslo can get: free horizon, no buildings, no trees, no hills. Computed for the 15th of each month with the solar model behind the reports (the method), rounded to the nearest half hour. No real wall gets more than this; most get less.

Southwest beats west — all year

If you can choose, southwest gives more than due west in every single month. At midsummer the difference is small: around ten and a quarter hours against nine and a half. But on 21 December a southwest wall sees the whole short day — all of its barely six hours — while a due-west wall only gets the last half. The reason is simple: at the winter solstice the sun rises in the southeast and never gets further west than southwest before it sets. A northwest-facing wall, by comparison, gets zero direct sun that day — and close to zero from November through February — the same wall that in June has evening sun until 22:42.

In winter, direction doesn't decide — obstructions do

On 21 December the sun in Oslo never climbs higher than about 7 degrees above the horizon. That low, almost anything takes it: a three-storey building then casts a shadow more than a hundred metres long. That is why "west-facing with great sun" can be true as a direction and worthless as a winter promise — the ceiling in the table above assumes a free horizon, and almost nobody in the city has one when the sun is at its lowest. Whether your wall keeps its December hours is decided by what stands in the way — not by the compass direction in the listing.

The direction is the ceiling. The address is the answer.

The table says what the direction can give. Our report measures what the address actually gets: sun hours for your floor and facade through the whole year, computed from laser data in which both the neighbouring buildings and the trees are standing — with whatever takes the sun named on a map.

Check what your wall actually gets →

We currently cover Oslo. The rest of Norway is coming.