It is common in north american design for small spaces to really squeeze the bathrooms and kitchens. Estonian firm Architect 11 shows different priorities; have a look at the plan here:
Almost a third of the plan is taken up by the sauna and the big shower room, while the toilet and laundry are in their own enclosure. There is a big dressing room that has a fold-down bed as a second function. There is also a version with a larger bedroom and no sauna, but it's interesting that this is what they build as their model home. It is the first of a line of prefabs that will extend up to large villas.
This series will enter into fierce and competitive prefab market. It is designed to fulfill the energy consuption requirements in nordic countries, even snow load requirements up to 3 kN. Houses are equipped with high standard ventilation systems, full automation and management systems, they are designed to utilize a solar heating during spring and autumn, have shelter from sun during summer months, thus not requiring a cooling system. Used building materials are in most parts wood, walls are vapour permeable and facades are ventilated. Structural frame is made of glulam, walls have rockwool insulation, internal walls are made of cross-laminated-timber panels, windows are wood-aluminium and furniture is either painted or laminated MDF boards.
There is a lot of glass, but a lot of overhang to shield it from the sun.
There are some unusual choices of materials for a prefab; most architects and builders go for lightweight materials. Here they use stone, even for the soffits of the big overhang. That's tough to do and is expensive. But they wanted a feel of solidity:
The design concept is intended to have more similarities with stone or concrete house than traditional wooden house. From original reinforced concrete design we maintained this simple form and ideology ...the outer form – stone-clad facade and cantilevered roof on top of the terrace – will act like protective shell for softer and warmer interior. The resulting form is one design element that is defining the architectural language for the whole series.