Minneapolis (demonstration)

The hot tub that feels like a stage

When in the tub is open for the hot tub after dark

Each month read on its 30th, or the last day of a shorter month · 2026

Works
Tight
No
Unanswered

Rings run from 5 pm at the centre to 11 pm at the edge. Schematic: A shape of the facts, not a picture of a particular date or a measured outline. Each month is its 30th, or the last day of a shorter month, not a promise about the other days.

In the tub is open for the hot tub after dark 7:00 PM to 8:00 PM, March to August. Shut September to February.

September to February: shut for the hot tub after dark. Light after dark is what stops it.
March to August: open 7:00 PM to 8:00 PM. Light after dark is what closes it.

The shut months are shut for one reason: light after dark. That is the thing to change if you want the season longer, and it is a different job from making the open months better.

The same year as a table

Month	Open	Usable hours	What decides it
January 30	shut	—	Light after dark stops it
February 28	shut	—	Light after dark stops it
March 30	7:00 PM–8:00 PM	1 h	Light after dark closes it
April 30	7:00 PM–9:00 PM	2 h	Light after dark closes it
May 30	7:00 PM–9:00 PM	2 h	Light after dark closes it
June 30	7:00 PM–10:00 PM	3 h	Light after dark closes it
July 30	7:00 PM–9:00 PM	2 h	Light after dark closes it
August 30	7:00 PM–8:00 PM	1 h	Light after dark closes it
September 30	shut	—	Light after dark stops it
October 30	shut	—	Light after dark stops it
November 30	shut	—	Light after dark stops it
December 30	shut	—	Light after dark stops it

In the tub for In the hot tub after dark. October 30, 2026 at 3:01 AM, America/Chicago. Now on this date. Confidence low.

Reading

For

Wet, mostly submerged, outside in the cold, and lit from the wrong angle.

In the hot tub after dark

In the tub works for the hot tub after dark at this hour.

“Works” means the model's weighted checks support this use, and no reading is past its own limit. A reading listed as close still needs attention; it does not mean every reading passed.

Wind is inside what this use needs: about 3 mph against at most 6 mph.
Privacy exposure is inside what this use needs: 0 / 100 against at most 30.
Light after dark is inside what this use needs: about 0 / 100 against at most 35.

Confidence low (49%). Treat this as a starting hypothesis, not an answer.

What this answer was built from

Use: In the hot tub after dark
Place: In the tub
Weather: Cold continental, short intense summer, long hard winter (scenario shape), scenario (from a published source)
Method: Traced geometry and radiation at this hour, measured against what this use needs

Try a change Make a document

What next here

Testing a change

4 of 8 milestones. The place is described well enough to ask what a change would do, and to find out whether the forecast was right.

Getting an honest answer4 of 4 done
- Placed on the earth — done. The sun is in the right part of the sky for this address.
- A spot to read — done. 1 spot is being read.
- What stands in the way — done. 3 things are drawn, so the shade is worked out rather than assumed.
- Who can see in — done. Privacy and sightlines can be answered here.
Testing a changeyou are here0 of 2 done
- A change tested — not done. Testing a change before buying it is the cheapest part of the whole exercise.
- A forecast checked — not done. A forecast nobody goes back and checks is a guess with a date on it.
Proving it well enough to spend money0 of 2 done
- Corrected against reality — not done. After a couple of rechecks the model can be corrected against this specific garden.
- Photographed — not done. A photograph is what turns a drawing somebody sketched into a drawing somebody can check.

Get this place to Annotated
A photographic check on the mapped sightlines and geometry. That makes privacy estimates more credible, but does not replace measured dimensions. Right now: Sightlines drawn from mapped observers remain provisional until their positions and heights are checked. The drawn heights have not been verified against the actual place. What is missing: Photographs of the actual place: None annotated. A photograph is how a drawn height gets checked against a real one. Photographs that know where they were taken from: No photograph has a position and a bearing, so what is marked on them cannot become a measurement.
2 things left
Test a change before you buy anything
The plan is good enough to ask what a screen, a tree or a canopy would actually do here — including the ones that turn out to be a waste of money.
a few minutes, nothing bought
Add a second spot and compare the two
One spot gives a verdict; two give a reason. Most of what is worth learning here is why one corner works at six and the other never does.
one tap, then read across

2 more things worth doing here

See how this spot changes through the year
A terrace that works in July can be unusable in September for reasons that have nothing to do with temperature. The same geometry read in four seasons is the cheapest insight here.
a read, nothing to enter
Photograph the spot and mark what is in shot
A photograph is what separates a drawing you sketched from a drawing somebody else can check. It is also how heights get corrected without a ladder.
one photograph

How well this place is described

Mapped

Quick
Mapped
Annotated
Measured

Shade, sky view and daily light are computed from the geometry on this plan. Unmeasured dimensions remain estimates, not verified measurements.

Sightlines drawn from mapped observers remain provisional until their positions and heights are checked. The drawn heights have not been verified against the actual place.

To reach Annotated

Photographs of the actual place: None annotated. A photograph is how a drawn height gets checked against a real one.
Photographs that know where they were taken from: No photograph has a position and a bearing, so what is marked on them cannot become a measurement.

What that buys: A photographic check on the mapped sightlines and geometry. That makes privacy estimates more credible, but does not replace measured dimensions.

Everything that was checked

Quick A place on the earth: Minneapolis (demonstration), with a time zone, which is what makes an hour an hour.
Quick Somewhere to read: 1 spot marked. A reading is a height at a place, and moving it moves the answer.
Mapped The things in the way: 3 objects drawn. The house counts, and so does the neighbour's.
Mapped What is underfoot: 1 of 1 readings sit on a mapped surface.
Mapped Where the property ends: Drawn, so the product can tell you when the cheapest fix stands on someone else's land.
Annotated Photographs of the actual place: None annotated. A photograph is how a drawn height gets checked against a real one.
Annotated Photographs that know where they were taken from: No photograph has a position and a bearing, so what is marked on them cannot become a measurement.
Annotated Who can see in: 2 observers marked.
Measured Heights off a tape: 1 of 3 objects are measured. The remaining 2 are this product's own inference, so no figure here is a survey figure yet.
Measured Something checked against the day: Nothing has been checked against a real afternoon. The model is unopposed, which is not the same as being right.

What to measure next

Ranked by how far the answer moves, not by a checklist

1What you are looking atSit in the chair
Mark the direction of the view worth keeping. No view has been marked yet, so nothing weighs what the view is worth, and a screen that blocks it looks free.
This is not a refinement. Nothing can answer this question until somebody marks it.
Mark it on the plan
Currently assuming: no view is being protected. Tested across one corridor changes what screening is worth doing.

BuildingNot yours (dashed edge)CanopySun’s path today (schematic)Can see inWhat a window can see, cut short where something is in the wayProposed

To scale · to the measurements given: Drawn to scale from the measurements given. Not a survey. It is not a survey.

Reading at

3:01 AM·October

The sun is down.

October 30 · In the tub Schematic

7:50 AM3:19 PM

Works (solid)
Tight (lined)
No (pale, edged)

The sun reaches In the tub at 7:50 AM. In the tub loses the sun at 3:19 PM because of the spruce.

The evidence behind this whole day is thin, so nothing on the strip is marked out as worse than the rest. The shape of the day is still the model’s best reading; the confidence in it is low, and it stays low until something it needs is measured.

In the tub does not open for the hot tub after dark on this day, and light after dark is the reason. It clears the same limits at other hours, but not the ones you would use it in.

Nothing in October clears what the hot tub after dark needs here.

The same day as a table

The same day hour by hour, in text.
Hour	Sun	Verdict	Confidence	Sun position
12:00 AM	dark	Works	a starting hypothesis
3:00 AM	dark	Works	a starting hypothesis
6:00 AM	dark	Works	a starting hypothesis
8:00 AM	in sun	Tight	a starting hypothesis	1° up, bearing 111°
9:00 AM	in sun	Tight	a starting hypothesis	11° up, bearing 122°
10:00 AM	in sun	Tight	a starting hypothesis	19° up, bearing 134°
11:00 AM	in sun	Tight	a starting hypothesis	25° up, bearing 148°
12:00 PM	in sun	Tight	a starting hypothesis	30° up, bearing 164°
1:00 PM	in sun	Tight	a starting hypothesis	31° up, bearing 181°
2:00 PM	in sun	Tight	a starting hypothesis	29° up, bearing 198°
3:00 PM	in sun	Tight	a starting hypothesis	25° up, bearing 213°
4:00 PM	shaded by The spruce	Tight	a starting hypothesis	18° up, bearing 227°
5:00 PM	shaded by The spruce	Works	a starting hypothesis	9° up, bearing 239°
6:00 PM	shaded by The spruce	Works	a starting hypothesis	0° up, bearing 250°
9:00 PM	dark	No	a starting hypothesis

When the sun arrives and leaves, to the minute.
When	What happens
7:50 AM	The sun reaches In the tub at 7:50 AM.
3:19 PM	In the tub loses the sun at 3:19 PM because of the spruce.

Direct sun at in the tub, month by month

Schematic · computed

In the tub gets the most direct sun in June, about 14 hours on the 30th, or the last day of a shorter month, and the least in January, about 7 hours.

Sun reaches the spot (solid)
Sun up, something in the way (lined)
Sun down (empty)

The grid, in a table

Hours of direct sun at In the tub on the 30th, or the last day of a shorter month, and when.
Month	Direct sun	When
January	7 h	8:00 AM–3:00 PM
February	8 h	7:00 AM–3:00 PM
March	11 h	7:00 AM–4:00 PM, 6:00 PM–8:00 PM
April	11 h	7:00 AM–3:00 PM, 6:00 PM–9:00 PM
May	13 h	6:00 AM–3:00 PM, 5:00 PM–9:00 PM
June	14 h	6:00 AM–4:00 PM, 5:00 PM–9:00 PM
July	13 h	6:00 AM–3:00 PM, 5:00 PM–9:00 PM
August	10 h	7:00 AM–3:00 PM, 6:00 PM–8:00 PM
September	8 h	8:00 AM–4:00 PM
October	8 h	8:00 AM–4:00 PM
November	7 h	8:00 AM–3:00 PM
December	7 h	8:00 AM–3:00 PM

The sun’s path on the plan, October 30, in a table

Where the sun is at each hour it is up.
Hour	Comes from	Height
8:00 AM	E (111°)	1° up
9:00 AM	SE (122°)	11° up
10:00 AM	SE (134°)	19° up
11:00 AM	SE (148°)	25° up
12:00 PM	S (164°)	30° up
1:00 PM	S (181°)	31° up
2:00 PM	S (198°)	29° up
3:00 PM	SW (213°)	25° up
4:00 PM	SW (227°)	18° up
5:00 PM	SW (239°)	9° up
6:00 PM	W (250°)	0° up

What the place is doing at 3:01am in October

Cold continental, short intense summer, long hard winter (scenario shape).

What it feels like

Estimatecold

32°F

Felt temperature

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

The air is 36.7°F. It feels about 4.7 degrees cooler than the air, near 32°F.

What is doing it

Take every named influence away and this reads 31°F. Air movement adds 3°F, How much sky is overhead takes off 2°F. That lands at 32°F.

How this was worked out

Air: 36.7°F from Cold continental, short intense summer, long hard winter (scenario shape), scenario (from a published source)
Radiant: 19.5°F mean radiant temperature
Method: Six-directional radiation integration, then ASHRAE operative temperature (from a published source)

Direct sun

Worked outafter dark

0 W/m²

Beam reaching this point

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

The sun is down.

How this was worked out

Sun: below the horizon
Traced: 0% of the beam reaches this point

Glare

Worked outnone

On the 0–100 reporting scale: 0 is none of it, 100 the top of the scale. Not a measurement.

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

Nothing bright is in the line of sight at this hour.

How this was worked out

Facing: 118deg (assumed, not measured)
Assumed: Which way the seat faces has not been set, so glare is estimated from the open direction. (assumed, not measured)

Privacy exposure

Worked outscreened

On the 0–100 reporting scale: 0 is none of it, 100 the top of the scale. Not a measurement.

The bar is the 0–100 reporting scale, mapped from the reading above; the tick is where this use stops working.

Nothing marked here has a usable line to this seat.

What is doing it

Left neighbour's landing window
+0.0
Right neighbour's bedroom
+0.0

How this was worked out

Observers: 2 marked
Method: Eye-to-eye rays, then scaled by how much brighter the seat is than the observer's own surroundings

Wind

Estimatelight

3 mph

Wind at the seat

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

Wind here is light.

How this was worked out

Reference: 7.1 mph at 10 m from Cold continental, short intense summer, long hard winter (scenario shape), scenario (from a published source)
At seat height: 2.9 mph before shelter
Shelter: 0% removed by what stands upwind

View

Unanswered

No view worth keeping has been marked, so there is nothing to weigh a screen against yet.

Surface heat

Estimatecomfortable

37°F

Surface temperature

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

The surface is running about 37°F.

How this was worked out

Surface: Concrete pad
Method: Absorbed shortwave against air temperature, flattened by air movement (from a published source)

Wetness

Estimatedries-fast

1 × the open

Drying time against the open

The bar is the 0–100 reporting scale, mapped from the reading above: 0 is none of it, 100 the top of the scale.

Sun and air movement here are enough to dry the surface at an ordinary rate.

How this was worked out

Drying rate: 0.000 in/hour here
Method: Penman combination equation on the radiation and air actually reaching this spot (from a published source)

Light after dark

Estimateinvisible

0 lux

Light on the seat

The bar is the 0–100 reporting scale, mapped from the reading above; the tick is where this use stops working.

The seat is not appreciably brighter than its surroundings, so a person there is hard to pick out.

How this was worked out

Fixtures: 1 placed
On the seat: 0.0 lux
Spill: 0% of output leaves sideways or upward

Ask something else about this place

Everything on the plan, in text

Thing	Reading	Standing	Note
The house	22 ft	You said so: You told us this, and it beats what the model worked out.	100 per cent solid.
Board fence	5 ft 11 in	Measured: Taken with a tape, a compass or a clock at the place.	95 per cent solid.
The spruce	30 ft	You said so: You told us this, and it beats what the model worked out.	90 per cent solid.
Left neighbour's landing window	blocked	You said so: You told us this, and it beats what the model worked out.	42 ft away, eye height 14 ft 5 in, 13 degrees above the seat.
Right neighbour's bedroom	open	You said so: You told us this, and it beats what the model worked out.	38 ft away, eye height 15 ft 1 in, 15 degrees above the seat.