A compact building forgives neglect less readily than a large one. The good news is that the list of things that genuinely need attention is short, and almost all of it is visible from outside.
Moisture before everything else
Moisture that would go unnoticed across 140 square metres becomes visible in 28 within one heating season. Ventilation is the first operational point in a tiny house, ahead of heating. Where heat-recovery ventilation is fitted, the job is to keep filters clean and the unit running. Where it is not, the job falls to the occupants — and February is exactly when nobody wants to open a window.
The façade sets the rhythm
Thermowood+ greys in a controlled way; that is the material behaving as intended, not failing, and it mostly needs looking at rather than treating. Coated composite panels and standing seam ask less, but they need clean junctions and free drainage to keep asking less. Whichever you choose, the roof, the gutters and the transitions around windows deserve one proper inspection a year — ideally in autumn, before the weather makes the inspection unpleasant.
What wears, and how fast
In a permanently occupied house: hinges, seals, taps and the shower area. In a let unit: the same list, three to five times faster, plus surfaces and soft furnishings. Budget a replacement reserve from the first year rather than discovering the number in the fourth. Nothing on this list is unusual — it is simply concentrated, because everything in a small house is used by everyone.
The long view
A load-bearing steel frame, a properly detailed build-up and a façade that drains are what make a thirty-year view reasonable. What shortens it is water finding a way in and staying there — around a badly resealed window, under a blocked gutter, behind furniture on an under-ventilated wall. Almost every serious problem in a compact building starts as a small, visible one.