Room

From Clanfolk Official Wiki

A Room is a place to avoid the elements.

When an area of the map is completely covered by Roofing and enclosed by Walls (with at least one door) it will be considered a Room and potentially provide benefit(s) to Clanfolk.

Benefits

The simplest benefit is protection from weather elements. In addition to keeping the Rain (or Snow) off the tiles covered by the Roof (which may also be achieved via roofing without walls) having walls will make it possible to keep temperature more stable.
Related to this is the ability to heat the room with a fire of some sort, especially useful during Winter. Room size (and fuel availability) will dictate what type of heating will be most efficient. (Tiles heated by each: Cooking Fire (108), Stone Fireplace (108), and Tiled Peat Stove (192). Torches provide negligible heating.)
N.B. It is not possible to heat a room above 15°C during Winter (25° during Summer).

Having a bed in a private room will grant the Clanfellow sleeping in the room a Mood boost for private room. Sharing such a room with a domestic partner will also provide the same benefit. Having a baby or other child in the room will negate that benefit, even if the baby is that of the couple. (Also, Pregnancy will not happen unless the couple is sleeping in a private room.)

Digging into a Mountain (with Mine Mountains Jobs) can allow rooms to be created inside the mountain, with a Mountain Roof over the room. That natural roof will provide the room with a cooling effect that can aid in creating a freezer effect for food storage. (Accommodation in such a room is comparatively unwise due to the lowered Temperature, especially during Winter.)

Utilising Door Locks at the entrances to rooms can keep Livestock away from seeds or other things they would otherwise eat. It will not keep Rats away.
It can also prevent Visitors (Traders, Travellers, Workers) to the Clan going to certain places; perhaps keeping them from eating certain foods, wearing clothing the player would prefer they not access, or intruding on couples wanting private time. (Zones might serve a similar purpose.)

Room Size and Mood

Clanfolk in bigger rooms generally have better Mood ratings.
The size of a room is determined by the tiles it covers, excluding all Wall tiles, so if a support column has been used due to Roof Span issues it will reduce the tile count. e.g. A six by six room will still count as Huge (see table) as the 36 tiles will be counted as 35. When using walls to block light from fires, create privacy for Toilets, etc. the count of wall tiles should be taken into account when determining room size.

Room Size impact on Mood
Tiny Room 1-2 tiles -500 Max
Small Room 3-5 tiles -200 Max
Medium Room 6-14 tiles No impact
Large Room 15-34 tiles +200 Max
Huge Room 35+ tiles +500 Max

Environment

Different sizes of Room and different construction material will have an impact on the Environmental effect on the Clanfolk inside. Some other things that will impact Clanfolk mood are having Decorations in the room, dirt on the floor, a lack of light, or some specific objects.

The best environment in a Room (sans decorations) will result from Fancy Floors (whether Tile or Wood), Stone Windows, Iron Clad Doors, and Brick Walls. (N.B. Roofing has no environmental impact.) Putting Floor Mats at the entrances (outside) will reduce dirt in the room, aiding in keeping it clean. Torches will provide light, negating the Low Light or Darkness mood Afflictions.