The patio that disappears into its own glass after dark
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 works is allowed to win.
Reading at
Sit outside after dark
What it feels like is2.0°F under— 51.6°F against at least 53.6°F
Radiant heat held by paving is what makes an evening terrace work at all.
Confidence low (33%). Treat this as a starting hypothesis, not an answer.
A second seat 19.7 ft south fixes what it feels like.
Ranked by what solves the actual limit with the least effort, not by the biggest number.
Not offered, and why
A second seat 19.7 ft south fixes what it feels like.
Put two chairs 19.7 feet to the south 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.
+0 hours of usable time on this day.
It does not meaningfully change the beam in either season.
Move the table 8.2 ft south-east improves things by 4 points without solving any single limit outright.
Slide the seating about 8.2 feet toward the south-east and change nothing else.
+0 hours of usable time on this day.
It does not meaningfully change the beam in either season.
Change Bright wall lantern to a warmer lamp does not move this in any way worth the effort.
Swap Bright wall lantern for a 2200 kelvin lamp of the same output. Blue-weighted light scatters more in the air, spills further into the garden and reads as harsher at the same brightness. Nothing structural changes; it is a lamp.
+0 hours of usable time on this day.
It does not meaningfully change the beam in either season.
Shield Kitchen through glass does not move this in any way worth the effort.
Fit a full cut-off shield to Kitchen through glass so the output goes down rather than sideways. The light on the table barely changes; the light on the neighbour's wall mostly stops.
+0 hours of usable time on this day.
It does not meaningfully change the beam in either season.
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.
It does not meaningfully change the beam in either season.
Remove Kitchen through glass and mark the route instead does not move this in any way worth the effort.
Take out Kitchen through glass and put low shielded markers along the route in from the house. Being the brightest thing in a dark garden is the same as being on a stage, and the light that makes the step safe does not have to be the light you sit in.
It does not meaningfully change the beam in either season.
Raise the bed 1.3 ft improves things by 3 points without solving any single limit outright.
Build the bed up about 1.3 feet with free-draining material. Roots sitting in water kill more plants than the wrong hardiness zone does, and lifting the root zone out of it is cheaper and far more reliable than trying to make the ground below drain.
It does not meaningfully change the beam in either season.
A paler paving does not move this in any way worth the effort.
Replace Dark wet patio 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.
It does not meaningfully change the beam in either season.
Relay it as a permeable surface does not move this in any way worth the effort.
Relay Dark wet patio as permeable paving or resin-bound gravel over an open sub-base. Water goes down instead of sideways, so the spot dries hours earlier after rain and stops holding the film that makes it slippery and green.
It does not meaningfully change the beam in either season.
A ventilated timber deck instead does not move this in any way worth the effort.
Replace Dark wet patio 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.
It does not meaningfully change the beam in either season.
Take up the paving and plant it does not move this in any way worth the effort.
Lift Dark wet patio 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.
It does not meaningfully change the beam in either season.
A deciduous tree 23 ft west of the seat does not move this in any way worth the effort.
A medium deciduous tree planted 23 feet to the west, grown to about 26 feet, with a crown roughly 19.7 feet across.
It does not meaningfully change the beam in either season.
Horizontal fins above the opening does not move this in any way worth the effort.
A run of fixed horizontal fins projecting about 2.3 feet from 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.
It does not meaningfully change the beam in either season.
A deciduous climber on tensioned wires does not move this in any way worth the effort.
Wires strung about 8.5 feet 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.
It does not meaningfully change the beam in either season.
A 9.8 ft umbrella does not move this in any way worth the effort.
A 9.8 feet canopy at about 7.5 feet, set square over the table.
It does not meaningfully change the beam in either season.
A shade sail over the seating does not move this in any way worth the effort.
A sail about 16.4 feet by 13.1 feet, set at about 9.2 feet and angled to shed water.
It does not meaningfully change the beam in either season.
An adjustable louvred roof does not move this in any way worth the effort.
A louvred roof about 13.1 feet square at 8.5 feet, blades running north and closable.
It does not meaningfully change the beam in either season.
A 8.2 ft awning does not move this in any way worth the effort.
A folding-arm awning projecting 8.2 feet from the house wall at about 8.5 feet, retracted out of season.
It does not meaningfully change the beam in either season.
A solid canopy over the seating does not move this in any way worth the effort.
A solid roof about 11.2 feet above the seating, 13.1 feet by 11.5 feet, guttered on the low edge. Unlike fabric it works in rain, and unlike a pergola it takes the winter light too.
It does not meaningfully change the beam in either season.
A pergola with open slats does not move this in any way worth the effort.
A pergola about 13.1 feet square at 8.5 feet with open slats, slats running roughly north.
It does not meaningfully change the beam in either season.