The pool surround nobody can cross barefoot

Buy nothing yetMove the table before you buy the pergola.

Before you buy a pergola, move the table.

Every change below is put into the plan and the whole model is run again. That is why a pergola's winter cost shows up here without anybody having written it down, and why the cheapest thing that actually buys hours back is allowed to win.

Fixing

For

Reading at

1:00 PM·October

In the sun. The sun is 41° up.

Where it stands now

Crossing it barefoot

The route to the water works for crossing barefoot 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.

Close to the limit Direct sun is 100 / 100 — 15 over (at most 85)Worked out: Computed from the geometry, the sun and the weather you gave it.
Direct sun is on this spot right now.
Sun on the crossing is only a problem because of what it has done to the slab for the last four hours.
Close to the limit Surface heat is about 122°F — 2°F over (at most 120°F)Estimate: Worked out, but at least one input was assumed rather than measured.
The surface is running about 122°F.
This is the one use where the ground decides everything and the air decides nothing. Skin blanches at about fifty degrees and burns not far above it, and a pale-looking paver in July sails past both.

What would change this. This would change if direct sun moved. A reversible test is how you find out whether the model named the right mechanism.

Confidence low (37%). Treat this as a starting hypothesis, not an answer.

What this answer was built from

Use: Crossing it barefoot
Place: The route to the water
Weather: Hot desert, brutal summers, almost no cloud (scenario shape), scenario (from a published source)
Method: Traced geometry and radiation at this hour, measured against what this use needs

The smallest thing that helps at this hour

A second seat 19 ft 8 in north

A second seat 19 ft 8 in north fixes surface heat.

Summer solstice, 21 June: still 1 hour usable.

Winter solstice, 21 December: still 7 hours usable.

No extra hours this daymove it

Nothing on the list buys extra hours on this day, so this is the least effort that still moves a limit.

Not offered, and why

Glare is not what is limiting this seat, so turning it changes very little.
No observer is marked, so there is no sightline to interrupt yet.
No observer is marked to screen from.
Wind is not the limiting factor at this spot, so a windbreak solves a problem you do not have.
Every fixture here is already fully shielded.
Nothing overhead here to hang a curtain from yet.
Nothing here has usable space underneath it.
The sun is high enough here that an overhead cover does this job better and blocks less.
No mature canopy here to work on.
No observer is marked to screen from.
No observer is marked to screen from.
No observer is marked to screen from.
Wind is not what is limiting this spot.
Wind is not what is limiting this spot.
Wind is not what is limiting this spot.
Wind is not what is limiting this spot.
Nothing here is relying on a deciduous canopy, so there is no winter gap to fill.
This point is a place for people, not a place for a plant.
This ground already sheds water quickly.
This surface already drains freely.
Every fixture here is already warm.
There is no lighting here to rearrange.

18 changes, tested at 1:00 PM in October

One at a time, so you can tell what caused whatLook at the plan

NoteYou have marked 2 spots here. Before building anything for this one, it is worth knowing whether another already works at this hour. Compare them side by side.

Does it have to suit you?

All 18 changes, in the order the engine ranked them. Say something about your situation and the ones that would not suit you get set aside.

I rent, so nothing permanentRules out anything that cannot be taken away again.
Nothing that needs a builderRules out changes that need footings, trades or a structure fixing to the house.
I want it working this seasonRules out planting and anything else that only works once it has grown.
I will not maintain itRules out anything needing regular watering, pruning or seasonal putting away.

CommitmentA projectPermanentYears to work

A deciduous tree 16 ft 5 in south of the seat

ForecastWorksstill Works

A deciduous tree 16 ft 5 in south of the seat fixes direct sun and surface heat.

A medium deciduous tree planted 16 feet 5 inches to the south, grown to about 26 feet, with a crown roughly 19 feet 8 inches across.

Gained: Direct sun
Surface heat
Lost: Nothing here.
Unchanged: Nothing here.
Still unanswered: Nothing here.

The test: A deciduous tree 16 ft 5 in south of the seat
If it worked: direct sun and surface heat no longer stops the hour.
If it didn’t: If the hour feels the same after you try it, the model guessed at the wrong thing.
Next evidence: Measure the actual height available before ordering: this is sized at 26 feet and about four inches either way changes whether it works.

+0 hours of usable time on this day. Opens 11:00 AM to 6:00 PM.

Summer solstice, 21 June: still 1 hour usable.

Winter solstice, 21 December: still 7 hours usable.

Solstice hours are how long this use can happen on those days. The beam sentence is one clock time, and a different number.

Summer beam up about 0 per cent, winter beam down about 18 per cent at this hour.

TestMove itYou can undo it

A second seat 19 ft 8 in north

ForecastWorksstill Works

A second seat 19 ft 8 in north fixes surface heat.

Put two chairs 19 feet 8 inches to the north and leave the main table where it is. The point is not to fix this spot but to stop needing it at the hour it does not work.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: A second seat 19 ft 8 in north
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Mark 19 feet 8 inches out on the ground and stand there before committing. The geometry is only as good as that distance.

+0 hours of usable time on this day. Opens 11:00 AM to 6:00 PM.

Summer solstice, 21 June: still 1 hour usable.

Winter solstice, 21 December: still 7 hours usable.

Solstice hours are how long this use can happen on those days. The beam sentence is one clock time, and a different number.

It does not meaningfully change the beam in either season.

TestA projectYou can undo it

A shade sail over the seating

ForecastWorksstill Works

A shade sail over the seating fixes surface heat.

A sail about 16 feet 5 inches by 13 feet 1 inch, set at about 9 feet 2 inches and angled to shed water.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: A shade sail over the seating
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 9 feet 2 inches and about four inches either way changes whether it works.

+0 hours of usable time on this day. Opens 11:00 AM to 6:00 PM.

Summer solstice, 21 June: 1 hour usable now, 6 hours with this change. 5 hours gained.

Winter solstice, 21 December: still 7 hours usable.

Solstice hours are how long this use can happen on those days. The beam sentence is one clock time, and a different number.

On the summer solstice: nothing named closes the usable span. With this change, surface heat is what closes it.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

CommitmentA projectPermanent

Raise the seating 2 ft 11 in

ForecastWorksstill Works

Raise the seating 2 ft 11 in fixes surface heat.

A raised platform lifting the seat about 2 feet 11 inches. It clears low boundaries, reaches faster air, and it works both ways: what you can see over, you can be seen over.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: Raise the seating 2 ft 11 in
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 2 feet 11 inches and about four inches either way changes whether it works.

+0 hours of usable time on this day. Opens 11:00 AM to 6:00 PM.

Summer solstice, 21 June: still 1 hour usable.

Winter solstice, 21 December: still 7 hours usable.

Solstice hours are how long this use can happen on those days. The beam sentence is one clock time, and a different number.

It does not meaningfully change the beam in either season.

CommitmentA buildPermanent

A pergola with close-spaced slats

ForecastWorksstill Works

A pergola with close-spaced slats fixes surface heat.

A pergola about 13 feet 1 inch square at 8 feet 6 inches with close-spaced slats, slats running roughly west.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: A pergola with close-spaced slats
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 8 feet 6 inches and about four inches either way changes whether it works.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

CommitmentA buildPermanent

An adjustable louvred roof

ForecastWorksstill Works

An adjustable louvred roof fixes surface heat.

A louvred roof about 13 feet 1 inch square at 8 feet 6 inches, blades running west and closable.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: An adjustable louvred roof
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 8 feet 6 inches and about four inches either way changes whether it works.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

CommitmentA buildPermanent

A solid canopy over the seating

ForecastWorksstill Works

A solid canopy over the seating fixes surface heat.

A solid roof about 11 feet 2 inches above the seating, 13 feet 1 inch by 11 feet 6 inches, guttered on the low edge. Unlike fabric it works in rain, and unlike a pergola it takes the winter light too.

Gained: Surface heat
Lost: Nothing here.
Unchanged: Direct sun
Still unanswered: Nothing here.

The test: A solid canopy over the seating
If it worked: surface heat no longer stops the hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 11 feet 2 inches and about four inches either way changes whether it works.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

TestMove itYou can undo it

Move the table 11 ft 6 in north

ForecastWorksstill Works

Move the table 11 ft 6 in north does not move this in any way worth the effort.

Slide the seating about 11 feet 6 inches toward the north and change nothing else.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Move the table 11 ft 6 in north
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Mark 11 feet 6 inches out on the ground and stand there before committing. The geometry is only as good as that distance.

It does not meaningfully change the beam in either season.

TestMove itYou can undo it

Two 8 ft 2 in parasols instead of one

ForecastWorksstill Works

Two 8 ft 2 in parasols instead of one does not move this in any way worth the effort.

Two parasols about 8 feet 2 inches across, set 7 feet 3 inches apart along the table. Between them they cover a rectangle, which is the shape a table actually is.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Two 8 ft 2 in parasols instead of one
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Try it on the plan, then go outside and see.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

TestAn afternoonYou can undo it

A 13 ft 9 in umbrella

ForecastWorksstill Works

A 13 ft 9 in umbrella does not move this in any way worth the effort.

A 13 feet 9 inches canopy at about 7 feet 7 inches, set square over the table.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: A 13 ft 9 in umbrella
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 7 feet 7 inches and about four inches either way changes whether it works.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

TestAn afternoonYou can undo it

Two low shielded lights instead of one high one

ForecastWorksstill Works

Two low shielded lights instead of one high one does not move this in any way worth the effort.

Add a pair of shielded 200 lumen fixtures at knee height near the seating, so the useful light is where people are rather than thrown across the garden.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Two low shielded lights instead of one high one
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 1 foot 8 inches and about four inches either way changes whether it works.

It does not meaningfully change the beam in either season.

TestAn afternoonYou can undo it

Add 1 ft 6 in of trellis to Block wall

ForecastWorksstill Works

Add 1 ft 6 in of trellis to Block wall does not move this in any way worth the effort.

An open trellis panel on top of Block wall, taking it from 6 feet 3 inches to 7 feet 9 inches. Open trellis blocks a sightline at an angle while letting light and air through, which a solid board does not.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Add 1 ft 6 in of trellis to Block wall
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 7 feet 9 inches and about four inches either way changes whether it works.

It does not meaningfully change the beam in either season.

TestA projectYou can undo itYears to work

A deciduous climber on tensioned wires

ForecastWorksstill Works

A deciduous climber on tensioned wires does not move this in any way worth the effort.

Wires strung about 8 feet 6 inches above the seating with a vigorous deciduous climber trained across them. In leaf it shades like a light pergola; bare, it gives back most of the winter sun a solid roof would have kept.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: A deciduous climber on tensioned wires
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 9 feet 6 inches and about four inches either way changes whether it works.

It takes the summer sun and leaves most of the winter sun, which is the behaviour worth paying for.

CommitmentA projectPermanent

An 11 ft 6 in awning

ForecastWorksstill Works

An 11 ft 6 in awning eases the hour without solving any single limit outright.

A folding-arm awning projecting 11 feet 6 inches from the house wall at about 8 feet 6 inches, retracted out of season.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: An 11 ft 6 in awning
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Measure the actual height available before ordering: this is sized at 8 feet 6 inches and about four inches either way changes whether it works.

It does not meaningfully change the beam in either season.

CommitmentA buildPermanent

A paler paving

ForecastWorksstill Works

A paler paving eases the hour without solving any single limit outright.

Replace Pool deck with a paler paving of similar mass. The surface itself runs cooler underfoot; the trade is that more light bounces back up at a seated person.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: A paler paving
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Try the reversible version first, even badly. A week with a borrowed umbrella tells you more than a drawing.

It does not meaningfully change the beam in either season.

CommitmentA buildPermanent

Horizontal fins above the opening

ForecastWorksstill Works

Horizontal fins above the opening does not move this in any way worth the effort.

A run of fixed horizontal fins projecting about 2 feet 4 inches from The house, set above head height. Geometry does the work: high summer sun is cut, low winter sun passes under, and the view out is barely touched.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Horizontal fins above the opening
If it worked: The route to the water works for crossing barefoot at this hour.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Try the reversible version first, even badly. A week with a borrowed umbrella tells you more than a drawing.

It does not meaningfully change the beam in either season.

CommitmentA buildPermanent

A ventilated timber deck instead

ForecastNofrom Works

A ventilated timber deck instead does not move this in any way worth the effort.

Replace Pool deck with a ventilated timber deck. Heavy paving charges all afternoon and radiates back until well after dark, which is why an evening terrace can feel hotter than the air. A light deck over an air gap is done within the hour.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: A ventilated timber deck instead
If it worked: The hour is easier, even if no single limit disappeared.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Try the reversible version first, even badly. A week with a borrowed umbrella tells you more than a drawing.

It does not meaningfully change the beam in either season.

CommitmentA buildPermanent

Take up the paving and plant it

ForecastNofrom Works

Take up the paving and plant it does not move this in any way worth the effort.

Lift Pool deck and plant it. Nothing else on this list moves surface temperature as far: paving in full sun sits twenty degrees or more above the air, while planted ground transpires and typically sits at or below it. It is also the only change here that gets better rather than worse over ten years.

Gained: Nothing here.
Lost: Nothing here.
Unchanged: Direct sun
Surface heat
Still unanswered: Nothing here.

The test: Take up the paving and plant it
If it worked: The hour is easier, even if no single limit disappeared.
If it didn’t: If direct sun still stops the hour after you try it, this was not the mechanism.
Next evidence: Try the reversible version first, even badly. A week with a borrowed umbrella tells you more than a drawing.

It does not meaningfully change the beam in either season.