Which floor gets the most sun? Sun on a window or balcony, floor by floor (2026)

Last checked: 22 October 2026. Written by the Flatwalk team.

Short answer. A higher floor gets more sun only until it clears whatever stands opposite. Below that line, the low winter sun is blocked for hours; above it, each extra floor adds almost nothing. Most of the difference shows up in winter: in spring and summer the sun is high enough to reach low floors too. So the best floor for sun is usually the lowest one whose windows look over the roof of the building in front, on the sunny side. To compare two floors at a real address, set one floor in a free sun tool, copy the link, change the floor and copy again.

Try it free: type the address, pick a flat and floor, see the sun at your window

Floor by floor: a worked example

A south-facing window in London looks at a five-storey block, 15 m (49 ft) tall, across a street 20 m (66 ft) wide. Here are the hours of direct sun on that window, floor by floor, with nothing else in the way. Storey 1 is the ground floor (the first floor in US terms).

What it shows:

• Floors 1 to 3 lose almost all their winter sun. On the shortest day they get under an hour, when the sun slips past the end of the block.
• Floor 4 gets back over four hours, and from floor 5 up the window gets every minute of sun there is.
• Floor 10 gets no more direct sun than floor 5. Higher floors still see more sky and a wider view, but not more hours of sun.
• In March and June every floor is the same here, because the sun is high enough to clear the block.

Facing west, the same block changes the summer instead:

A west window on the ground floor loses about four hours of June evening sun to the block; from floor 6 up it keeps them all. In December the low sun reaches a west window from the southwest, round the side of the block, so the floors differ less.

The rule that tells you which floor clears the block

A building opposite blocks the sun whenever the sun is lower than the angle from your window to its roof. Turn that round: your window clears the block at midday when it sits higher than

the block's height, minus the distance to it times the tangent of the sun's midday height.

At midday on 21 December the sun is about 15° up in London (tangent about 0.27), about 26° in New York (about 0.49), about 23° in Toronto (about 0.42) and about 17° in Vancouver (about 0.31). In the London example: 15 m minus 20 m × 0.27 is about 9.6 m, so windows above about 10 m, from storey 4, see the December midday sun. That matches the table.

The same sum works for any city and block: the further north you live, the lower the winter sun, and the higher you need to be.

Tall towers: a New York example

A south-facing window in New York looks at a tower about 20 storeys tall (60 m, 197 ft), 30 m wide, 25 m (82 ft) away:

A narrow tower takes a block of hours out of the middle of the day, while the sun passes behind it. Every floor below its shadow line loses the same block. By the rule above, a window here needs to be above about 48 m to see the December midday sun.

Other things that change by floor

• A balcony above. On every floor but the top, the balcony of the flat above can shade your window. A deep balcony shades a south window in summer, when the sun is high, more than in winter.
• Trees. A tree in front shades the lower floors and not the ones above it. Trees that drop their leaves let more sun through in winter.
• The building next door. A taller neighbour to the east or west takes morning or evening sun from the lower floors first.
• What may be built. An empty plot opposite can take a lower floor's winter sun in a few years. Search the planning applications for the plot, or the plans for the towers around a new development.

Compare two floors, step by step

Flatwalk's free tool, Sun at your window, lets you set the floor and read the hours on your window.

1. Type the address under "See the sun at your window", and find the building on the satellite map.
2. Choose A flat ("One floor of this building"). Tap the building's corners on the roof (corners and walls snap). Set the number of storeys, Your floor and the storey height.
3. Put the window on the wall. Each wall has a tag, such as "South wall · sun side". Tap the wall, then tap where the window is, or drag to draw it. Pull out a balcony or overhang above if there is one.
4. Read the sun. Tap Shortest for December, then a spring month, and read the hours, the first and last sun, the 12 month bars and "What takes your sun".
5. Copy the link. It saves the floor, the window, the date and the hour.
6. Change the floor. Go back to the building step, set another floor, and read again. Copy that link too.
7. Open both links side by side to compare.

If the building opposite looks too low or too tall, tap Something off? and fix its height.

What it cannot tell you

• Modelled, not measured. The hours are worked out from maps and the sun's position, not from a light meter at the window.
• Where the data is best. Building heights are measured in London, Manchester, Cardiff, Edinburgh, Glasgow, Berlin, Munich, Hamburg, Warsaw, Kraków, Wrocław, New York City, Chicago, Toronto, Vancouver and Montreal. Elsewhere they are estimated, and the tool says so; outside the areas it covers in the UK, Germany, Poland, Lithuania, the US and Canada it is slower and treats the ground as flat.
• New buildings and trees. Buildings finished after the map data, and trees planted or cut since about 2017 to 2019, are missing or wrong until you add or fix them.
• Weather. Typical weather is a monthly average from 2005 to 2023, not a forecast, and can be about 10 to 15% off.
• Windows only. It does not measure a terrace floor or a roof.
• Not a legal or certified report. It is not a right-to-light survey.
• Small things it ignores: window frames, glass tint and your own roof shape. Map outlines can be a metre off the real wall.

Try it free: compare the sun on two floors

What Flatwalk does that older planners skip

Lights

Add ceiling lights, lamps and LED strips and see where you need them after the sun goes down.

Your flat in its city

Enter your address and the street and buildings around you appear in 3D, wherever the map has them.

Sun for your address

Real sunlight by date and hour, and how long each room gets direct sun.

One piece, in your own room

Through the live camera or in a photo of the room, stand a sofa on your own floor at its true size.

Detail

Window and door types, kitchens, wardrobes and bathrooms built piece by piece.

Made for a thumb

Slide the hour with one finger and watch the light move through the rooms.

Swipe for more. Every picture is the app itself.

One flat, free

Questions people ask

Which floor gets the most sun? The lowest floor whose windows clear the roof of the building opposite, on the sunny side. Above that, extra floors add little or no direct sun; below it, the winter sun is blocked for hours.

Does a higher floor get more sun? Up to a point. A higher floor gets more winter sun until it looks over the building in front; after that the hours of direct sun stay the same, though you see more sky.

Is a ground floor flat dark? It depends on what stands opposite and which way it faces. With a tall building close by to the south, a ground floor window can get under an hour of sun in December; with open space in front it can get as much as the top floor.

What is the best floor to live on for sunlight? The lowest floor that clears the buildings in front of your main windows. Find it with the rule above, or compare floors in a sun tool at the real address.

Does a balcony above reduce the sun on my floor? Yes, mostly in summer, when the sun is high. On a south window a deep balcony above shades the summer midday sun and lets the low winter sun in underneath.