Door

Doors provide entry points through walls for colonists while still keeping out enemies and wild animals.

Acquisition

Constructing a door requires 25 Stuff (Metallic/Woody/Stony, 250 for SMVs) and 850 ticks (14.17 secs) of work.

Summary

Doors mostly act like walls. Doors are valid structures for supporting roofs and creating rooms. Opening a door will make heat transfer faster. Note that the room is still considered enclosed for temperature mechanics. So, unlike a hole in the wall, an open door will not equalize temperature instantly with the outdoors. Doors do not block the interaction spots of buildings.

Doors can be opened by colonists, regular animals, slaves and friendly mechanoids. Doors cannot be opened by raiders, pen animals, manhunter animals, or prisoners (usually). Prisoners in a prison break can open doors. Doors can be "Held Open" by selecting the door; the next time something passes through it, the door stays open.

Doors can be forbidden, also by selecting the door. Colonists and other tamed pawns will not pass through it. However, colonists under a mental break will ignore restrictions. Visitors and traders also ignore restrictions. Human and mechanoid raiders will try and break a door if there are no other paths. Manhunter animals will only try and break doors if they see something go inside it.

Analysis

Material choice

Typically, a colony constructs their first doors from wood, which is light and so opens more quickly than other doors. However, wood is both flammable and comparatively weak against attacks, so proves vulnerable as the early game moves into mid-/late-game conflict. Despite this, as interior doors, they are often still quite suitable, at least until better options are available.

Once they can be afforded, steel doors are a good balance of durability, flame resistance and price. The next step up for doors that are often closed/opened would be plasteel, a precious material but unsurpassed in strength for defensive positions.

Stone doors can be problematic because they open so slowly. However, they do have a 0% flammability, making them a nice option for a firebreak at key locations; select them to be Held Open for normal traffic, and draft/shut them if/when the need arises. They can also be used for areas that are rarely entered, perhaps your chemfuel powered generators (which only need to be fueled once/6 days), or for the switch to a bank of emergency batteries. If you do choose to make use of stone doors, granite is your strongest choice, and is no slower than any other stone.

Once autodoors have been researched, and you have the power and component supplies to reliably operate them, standard doors can be replaced with alternative materials and not slow down traffic at all, or at least slow it far less.

Temperature Regulation

Similar to double thick walls, double doors (not side-by-side, rather, both in the path of travel) improve insulation and reduce temperature equalization. A door can be left permanently open (mark the door to 'hold open' and have a pawn pass through) to help control temperature. Open doors allow temperature to more quickly equalize between rooms, or outdoors for exterior doors. Equalization through open doors is less potent than vents.^[Verify]

Mini-rooms

Because doors do not block the interaction spots of buildings, it's possible to build "mini-rooms" that are only large enough for the building itself, with the door at the interaction spot. Mini-rooms are best used for buildings that don't damage pawn mood when used in cramped quarters, such as cryptosleep caskets and biosculpter pods, or buildings that see only very brief use, such as a comms console.

These rooms are especially useful for biosculpter pods: mini-rooms only require 6 tiles of sterile tile per pod for maximum cleanliness. (While the door's tile does not need to be sterile tile itself, it does need to be kept free of dirt for the best bonus to apply.) The door can be held open to maximize speed of access while still maintaining the cleanliness bonus.

A biosculpter "mini-room" with a pawn undergoing sculpting. The pod is selected to show the interaction point, which overlaps the door. The pawn in suspended animation does not care about the tiny space. The door should probably be held open for easier nutritional loading and for emergency medic cycles.

Stats table

Door	Beauty	Work to Build	HP	Flammability	Door Speed	Market Value
Material	Beauty	Work to Build	HP	Flammability	Door Speed	Market Value
Bioferrite	0	002,125 ticks (35.42 secs)	320	75%	100%	26
Gold	20	000,765 ticks (12.75 secs)	96	40%	100%	2,505
Granite blocks	0	005,240 ticks (1.46 mins)	272	0%	45%	41
Limestone blocks	0	005,240 ticks (1.46 mins)	248	0%	45%	41
Marble blocks	1	004,815 ticks (1.34 mins)	192	0%	45%	40
Plasteel	0	001,870 ticks (31.17 secs)	448	0%	100%	230
Sandstone blocks	0	004,390 ticks (1.22 mins)	224	0%	45%	38
Silver	6	000,850 ticks (14.17 secs)	112	40%	100%	255
Slate blocks	0	005,240 ticks (1.46 mins)	208	0%	45%	41
Steel	0	000,850 ticks (14.17 secs)	160	40%	100%	51
Jade	10	004,250 ticks (1.18 mins)	80	0%	100%	140
Uranium	0	001,615 ticks (26.92 secs)	400	0%	75%	156
Wood	0	000,595 ticks (9.92 secs)	104	100%	120%	32