Pokemon GSC/HGSS: Johto's Domestic Architecture
Before we begin, please note that none of the following information applies to the Blackthorn or Dragon Clan communities. Blackthorn's architecture is based off of the Dragon Clan's, and the Dragon Clan itself was established as a separate entity from Johto and only assimilated into the region much later. Therefore, traditional homes in the Blackthorn region of Johto resemble gassho-zukuri minka far more than they do other Johtonian homes.
Even in modern times, Johtonian architecture tends to focus on verticality. Much of the region is heavily forested, so pioneers would have to fell trees to make space before they could settle in wooded areas. Limiting the horizontal spread of a building reduced the effort and resources that needed to be spent before building could even begin. Most houses will host the kitchen/living area on the ground floor in a single, open room, private quarters are relegated to the second floor, and an attic will occupy the inside of the roof.
Urbanization pushes this concept further. In more developed areas such as Inner Ecruteak (imagine Ninenzaka of Kyoto), most buildings have expanded to crowd against each other. In this case, the ground floor's front room may be dedicated to a family business in order to best utilize street access, while the back rooms have the kitchen/living/storage areas and the upper floor houses the family's private quarters, similar to real-life machiya. Even in a cityscape like Goldenrod, apartments and offices often have separate establishments like markets or eateries occupying the ground floor.
Regardless of the overall structure, most houses will have at least three bedrooms, as Johtonian family units are multigenerational. Due to the aforementioned limited space, the eldest son would live with and take care of his parents and their assets while any younger brothers moved out and settled in the immediate area---daughters were expected to move in with their future husbands. Therefore, homes needed at least one bedroom for the eldest son and his wife, one bedroom for the son's parents, and one bedroom for any and all children (though in particularly small homes, children may have shared a room with their grandparents), as well as an optional guest room depending on how wealthy the family was.
While exact circumstances vary, many family units still follow this general model. However, in modern times, it's becoming increasingly popular for young adults to move out on their own regardless of gender or birth order. Additionally, apartments in urban areas typically lack the space necessary to house these extended families.
From Violet City's honmune-zukuri style homes to Cherrygrove's fishing huts, the visual aesthetics of Johto varies based on the local population's needs and the materials available to them. Despite this, many of the foundational building techniques remain consistent.
Modern homes replicating the style of Johtonian minka may use a concrete foundation, but historically, stone was almost never used except in areas of abundance like Cianwood. Instead, foundations would be raised off the ground as to avoid flooding from the region's rainy climate, leaving a crawlspace underneath. The frame is always built out of lumber (usually cedar/sugi due to its overwhelming abundance) and held together using interlocking joints; the walls are also usually made of wood, but buildings constructed between ~50-300 years ago may use mud plaster as a result of cultural exchange with Kanto. Thatch roofing used to be common, but because of the dedicated effort needed to cultivate it and the rate at which it needs to be replaced, most traditional homes that are still in use have been renovated with shingles instead.
Through the front door of all Johtonian homes lies the genkan, or entryway, where shoes must be taken off before entering the house fully. Not all genkan look the same. Sometimes, it may be located a step below the main floor. Other times, it's on the same level but is distinct from the main floor in that it's covered in tile or some other material that is easy to clean. Some particularly old homes still have a doma---Moomoo Farm has a doma that has been refloored with hardwood. In the case of Lyra's home, and many other smaller-sized homes like it, there's not enough space to have a properly designated genkan that wouldn't be in the way of indoor foot traffic. One common solution is to use a large mat or rug as a temporary genkan that can be laid out and put away as needed. Regardless of construction, the entryway will usually be furnished with a seat, a designated shelf or cubby for shoes, and a place to keep umbrellas and coats.
Once a visitor has made it inside, there are two places to host them: the dining table, or the family's sitting area. The dining table is reserved for more formal occasions including business matters, delivering important news, or receiving guests that are far above the host's own social standing. Otherwise, Johtonian hospitality hinges on treating guests as if they're part of the family, and so casual visitors will be herded towards the family's sitting area. Because of Johto's cooler climate, the sitting area historically was centered around a hearth, but with the evolution of technology, this has been replaced by the kotatsu. The sitting area may also include other furniture such as couches/armchairs, storage (particularly for the kontatsu's blankets, which are put away during warmer months), entertainment, and decoration, but the kotatsu will always remain the centerpiece of domestic life. Visitors aside, residents may choose to switch between the dining table and kotatsu as a situation demands. Additionally, residents in particularly small spaces like apartments may only have room for one table, so the prior distinctions become irrelevant.
Also important to the Johtonian household is the kamidana, located high atop a shelf or cabinet. These small shrines are most often dedicated to Ho-Oh, but may also include local deities such as the Dragon Clan's Lugia or Azalea's protector of Ilex Forest. Because these deities are considered as deeply ingrained into Johto's landscape as the forests, plains, and mountains, the contents of a kamidana can be incredibly simplistic, versatile, and suited to a resident's needs and tastes as long as it reflects the local geography. For instance, the kamidana in Lyra's home only has a glass bottle filled from the local river and a candle that is lit on important occasions like holidays and birthdays. Every person must greet the kamidana with a short bow when leaving or entering a house---this habit is so ingrained in Johtonians that they often find themselves bowing to nothing in particular when visiting homes in foreign lands.
Lyra's home only has two bedrooms, one of which is the master bedroom, and the other of which currently serves as a spare room. Both rooms have oshiire, or built-in closets, that are used to store bedding, clothing, and other items. The closet in the spare room also holds futons for hosting overnight guests. Modern sleeping arrangements consist of a mattress and frame, as is the case in the master bedroom, but futons are suitable for temporary arrangements. Beside the closets are shleved alcoves that may be used as addition storage or a desk.
The bathroom is always located in a central area of the house as to be easily accessed by residents and guests alike. Bathrooms tend to be small and simplistic, consisting of only a toilet, sink, and bathing area. Modern homes, and some older homes that have been retrofitted, will also have a washer and dryer in the bathroom, but they are still uncommon enough in lesser-developed areas that handwashing or visiting a laundromat remain common practices.
Johtonians bathe sitting down on a shower stool using a fauceted washbasin, some kind of scrubbing implement, and a pitcher or shower head to rinse off with. To avoid splashing water across the floors, the bathing area is partitioned off from the rest off the room, often by a water-resistant folding screen. These folding screens used to be made out of woven grasses, but waxed fabrics or plastic are now more common due to their longevity. Some houses may even install glass sliding doors.
Full-body baths used to be a luxurious commodity because of the time and effort required to warm such large quantities of water in Johto's cooler climate. With the introduction of water heaters, Kantonian-style bathtubs have become more popular---though some people, particularly older generations, consider it distasteful to stagnate in the same water as the dirt they're washing off. Furthermore, public bathhouses, as are popular in Sinnoh, are completely alien and offputting to Johtonians because of the immense privacy associated with bathing.
The attic is typically accessed by a loft ladder, and is where the bulk of storage is located, functioning as a nando. Even if an attic is divided into rooms as per the resident's needs, it's very rare for those rooms to legally qualify as a living space due to insufficient lighting/ventilation/other requirements, and at least one of those rooms will always be reserved for stowing away seasonal (or otherwise seldom used) items. In this case, Lyra's bedroom occupies most of the floor space, but the oshiire on the right are fully dedicated to household items, so her personal belongings are kept in her dresser, at her desk, or under her bed. Not pictured are a variety of boxes, plastic tubs, and other dusty clutter that also line the eastern wall.