I just want to add some things that people must take into account when creating Sigil. I'll continue to add as I get more. People may also add to the list if they feel the need.
- Its blanketed in a haze of fog (soot laden air)
- Its constantly filled with the sounds and smells of a thousand, worlds, planes and their inhabitants
- Low hanging clouds, cities weather
- It has a dreary atmosphere, but also an amazing one.
- Sights and smells of cooking fires are abundant
- It isn't always a very pretty place
- The Ladies Ward has the least fog
- The Lower Ward has the most
- The area around the great foundry consists of a myriad of workshops and forges
-The foundry itself produces a yellowish smog that does spread to the other wards
- The fog clears up and worsens constantly
- Occasional acid drizzle (take note that some areas will show such weather damage)
- High eved buildings
- Blades, ornate spikes adorn walls and monuments everywhere.
- Birds of numerous types and breeds are found roosting or are impales on some blades
- All building tend to be unique in architectual style ie. No building is exactly alike
- Multicultural to the max
- traditional blades, spikes, spiked fences and stone ornamention apparent.
-Razorvine weeds is EVERYWHERE
- Racial enclaves and ghetto communities may differ from the more traditional Sigillian acrchitecture
- The blades and spikes are often used as security measures against, thieves and tresspassers
- Abstract, carved ornamentation and gargoyles or imitation perched figures are fairly commen (made of iron and stone)
- the more elaborate the ornamentation design the more wealthy the building occupant and owner
- Water spouts, eves and such are most common in the richer areas of Sigil, but are not exclusive to those areas.
- Iron and worked stone is the most common building matierial.
- Richer buildings may sometimes have wood implemented into the structure somehow
- grey or white stone, iron or slate, or rough hewn wood make up the the majority of the city.
- Sigils "ore" is useless as it weaken and crumbles the instant it is mined, so no building should be made from it.
- Razorvine is occasionally used as a deadly security measure in some parts and may cover some buildings
- Razovine is a commodity in Sigil, used as animal feed, cheap fire fuel, etc so expect vine bales and stall to sell it to some extent
Those are the basics so far. I've more detailed notes on the various wards but we should do each step by step I think.
Alternate-History Technologies in Planescape?
Don't forget the steam-punk aspect.