How would daylighting influence architecture in a dense, multimilion city on a planet orbiting red dwarf?

Question

How would daylighting influence architecture in a dense, multimilion city on a planet orbiting red dwarf?

Setting: partially rebuilt post apo world (with human settlers)

Technology: comparable to early XXIst century

Affluence: first world equivalent

Astronomical conditions: earth like planet, tidal lock, no significant flares

I see two main issues that would be clearly different - day all time (I really doubt someone would build a city on the dark side of planet ;) ) with all the time same direction of the “Sun”. Different colour of light (much more red light, clearly less blue and violet) what can be approximately calculated using black body radiation.

OK, so how it would influence architecture? (assuming that there is no strong influence from local taste and zoning law is simply based on what’s the most practical in local conditions)

Idea 1: Difference is barely noticeable except no street lights or neon lighting.

Idea 2: Utilize the light perfectly by building windows perfectly directed towards the “Sun”. In denser district the best shape would be somewhat simmilar to prism so from one side windows would get the maximum possible amount of light. (So flat would tend to be long, narrow, with living room having huge windows, while deeper inside there would be all other rooms like bathroom, kitchen or bedrooms)

Idea 3: This light has got awful colour, who cares. I mean in order to get any normal light colour one would have to either use some green and blue lamps, or less densely populated areas just have big windows made of blue glass. If this light is so problematic to use and artificial light would have to be used anyway, maybe most of people would consider as simpler idea just to use artificial light. Then people would quite easily accept that their flat / office / whatever is without any windows what would encourage to build a multilevel district size buildings.

Or maybe something else?

Answer 1

First, red dwarfs aren't as red as you might think. Within the star system, they would look more orange-ish at best, and in fact will emit full spectrum light that is bright enough to look mostly white.

With that out of the way, the main thing will be the tidally locked orbit; the angle of the star's light (we'll just call it sunlight, ok?) will always be (nearly) the same, so windows will be built to take advantage of that, and architects could make much better use of mirrors for artistic reasons or to funnel natural light into hard-to-reach places.

If the red dwarf is close enough to give you a mean surface temperature above freezing, it'll be close enough to be an attractive energy source.

Solar panels would be much easier to incorporate into architectural designs, since they would be far more effective due to constant sunlight (barring bad weather), and would not need to be rotated to match the sun (at worst, they'd need to be wobbled a bit due to eccentric orbit or axial wobble, but nothing as bad as what we have to do on Earth).

Shaded areas would be easier to build (and probably more important). As with the other things, they'd always be in the same spots, so you might see dedicated shade hangout spots for people to socially congregate to get out of the sun, rather than just finding a tree or side of a building like we do on Earth. I'd quite like that, actually.

Answer 2

If the planet is tidally locked to the star (I'm not sure that's possible, but let's assume it is), then not only is it day all the time, but the position of the sun will be fixed in the sky. This results in

• windows only on one side of buildings
• buildings have a hot side, and a cold side, and would maybe require help with thermal distribution
• air would constantly rise on the warm side and fall on the cool side, which could be used for heating/vents

In addition, since shadows will not move, extra consideration would be paid to:

• incorporating shadows into the buildings aesthetic lines
• shadows cast by buildings on their neighbours will likely be regulated
• slums may arise in the shadowed areas behind very large buildings, as I assume sunlit spaces would be much more expensive

About color, the red dwarf will be supplying mostly red light. Just putting a pane of blue glass on front of that won't do anything, in fact the glass will be entirely black and opaque, since blue glass only allows blue light through it. If the only light source is red, the glass will appear black. For unadapted humans, they will have powerful white lighting indoors, and possibly outdoors too. Advertisers will no doubt have a lot of fun with eye-catching use of color. High-contrast building materials may be popular, especially if they reflect the non-red colors and absorb red (so either appearing somewhat colored, or black).

Building prism-shaped buildings is not an efficient use of space. The same amount of light will fall in any case. A prism building will only have more difficulty distributing the light to its center. Use louvered windows, terraces, and mirrors to direct light throughout a regular rectangular building form.

My guess would be that a direction like North would be rather arbitrary. Instead, orienting blocks and streets to be Sunward seems much more likely.

You may see very large scale use of mirrors to reflect sunlight around the sides of buildings, into side streets and dark areas, etc.