If we haven’t traveled to other regions or countries much, we might not think architecture is part of culture, but it can be. We take the architectural style of where we live for granted but notice it in places that look very different. In some rural regions, a wrap-around porch is very common. In towns, bright pastel colors may dominate exterior walls, or everything is bright white stucco. In still others, murals or graffiti abound. Each of these influence the impression architecture creates, and this impression may be what we’re most after.
Saying construction is brooding and menacing, or quaint and homey, is more useful than using technical terms for building styles because many of us (including audiences) don’t understand those terms; authors should use them sparingly if at all. Materials can be commented on, such as clay, wood, stone, and metal, because these imply sophistication, sturdiness, and overall impression, and are easy visualize. The vibe that materials impart can influence how we feel about a place.
A log cabin with a thatched roof, or one made of bamboo, gives a very different impression than a steel and glass building. In between are buildings made of stone, tiles, and synthetic materials. The hue of these contributes to the impression of a location as drab or colorful, but this becomes cultural when such a style is not just in architecture but clothing and more.
Regardless of material, we can leverage the reality that villages often have narrow streets from when people only walked or rode a horse. Many roads aren’t wide enough for a wagon. Anyone who’s traveled to Europe has likely seen an “old town” where everything about the architecture is smaller, including the space between buildings.
One way to decide on styles is by government type. An authoritarian regime may be reflected in menacing, dark architecture that intrudes upon the psyche. A democratic one may favor bright colors and greenspaces. One that prizes order is likely to have well-designed spaces, possibly with geometrical layouts that include how gardens are structured. A poorly run or chaotic government might have housing that has sprung up wherever it could, where little planning has taken place; this could be true if war has taken a heavy toll, causing governments to rise and fall in quick succession over the past hundred years, leaving people on their own to “make do.” Even when a more successful government takes over, it may leave such slums as they are, even if crime and disease run rampart there. Such places intrude on culture because people consider the safety (or lack thereof) of them. It isn’t just homes that are affected, of course, but public buildings that are likely financed with taxes. Private businesses built and paid for by a company are impacted less in a fantasy setting where these companies don’t exist.
Necessity often dictates culture. Those in a medieval town may dump a chamber pot out a window into the street. Is this considered standard in our culture or are these people breaking a local law? The stench of many doing this could lead to people wearing a perfumed scarf over their lower faces; this becomes cultural and can outlast the original cause when society advances and people stop dumping poop in the street. Urban, suburban, and rural areas often have different styles, sometimes due to necessity or industry.
Culture affects the interior of buildings, too. In the United States, for what’s called a single-family home, we expect certain rooms. On the first floor, it’s the kitchen, dining area, formal dining room, formal living room, casual family room, an optional garage, and the laundry room (which might be on the second floor instead). On the second floor, we mostly expect multiple bedrooms and associated bathrooms. There may be a basement, and this could either be finished or unfinished with multiple rooms. Two stories with the optional basement is common in many areas, while single story, rambling houses appear in other areas and times. We can add expected rooms, such as ones dedicated to magic, religion, target practice, or weapons play. Rooms can also be designed with certain activities in mind but converted to another, such as a spare bedroom being used for a nursery. If our culture has a siesta, there is likely to be a room for this, or part of one, if people don’t always do this in their bedroom. This room might be closer to the front of the house for not only themselves but a guest to use.
Consider whether there are species and races of different heights in the setting and whether this is considered. For example, do dwarven homes have a front door tall enough for humans, and social room, too, but father inside, where guests are rare, the doors and rooms cater only to dwarves? If this is true in a society, people will expect and reach a conclusion about a dwarf whose home is exclusively dwarven-sized. Is he anti-human, for example? Or was this the only one available, prompting him to apologize to human guests all the time? Do people talk about him being anti-human behind his back?
Something we can leverage from history is the existence of utilities such as running water, power, and appliances. These impact the cleanliness of our inhabitants and their general fitness and longevity. Technology and medicine are the primary reasons that those of us alive today live much longer than in the past. In SF, we may just assume these (and better versions) exist, but certain things may or may not in fantasy. For example, running water actually can because it doesn’t depend on electricity.