42 m² with 450 group addresses — more than the 67 m² apartment next to it
- Floor area
- 42 m²Floor area
- KNX devices
- 35KNX devices
- Group addresses
- 450Group addresses
- Of them named
- 100 %Of them named
Overview
A 42 m² city apartment, handed over in 2025 after eight months of works. Lighting, blinds, air conditioning and multimedia on Iridium. It is the smallest object we have published, and it answers a question we are asked often: whether automation makes any sense on a small floor area.
Challenge
The assumption behind the question is that a small apartment needs a small system. The data from our own two apartments says otherwise: this 42 m² flat carries 450 group addresses on 35 devices, against 362 addresses on 29 devices in the 67 m² one. Sixty per cent more floor area, fewer of both.
The reason is that automation follows functions, not square metres. A studio still has heating, cooling, a temperature setpoint, blinds, several lighting circuits and an extract fan — the same list a house has, only pressed into fewer rooms. What scales with area is the number of rooms; what scales with the address count is how many distinct things have to be controlled and reported.
The constraint is physical rather than logical. Everything has to fit one small distribution board, and every device in it dissipates heat into a cabinet that has no room to spare.
Solution
The address structure is the one we would build for a house: separate groups for heating, for cooling, for temperature setpoints and for the thermostat indication on the switches, rather than one climate group holding everything. On 42 m² that looks like overkill and is not — it is what keeps a change to the cooling logic from touching the heating, and what makes each of the 450 addresses findable by its function rather than by memory.
All 450 are named. There is no size of object at which naming stops paying: the next engineer opening a small project has exactly the same problem as the one opening a large one, minus the excuse that it was too big to keep tidy.
Five manufacturers appear on 35 devices, including an Elsner weather and an air conditioning gateway — an unusually wide spread for the floor area, and a direct consequence of the scope being a house's scope rather than a studio's.
Systems & Technologies
In numbers
- Group addresses
- 450Group addresses
- Named, none left blank
- 100 %Named, none left blank
- KNX devices
- 35KNX devices
- TP line
- 1TP line
- Vendors on 42 m²
- 5Vendors on 42 m²
- More addresses than the 67 m² flat
- +24 %More addresses than the 67 m² flat
Project Details
- Object type
- Apartment
- Area
- 42 m²
- Commissioned
- 2025
- Technologies
- KNX
Discuss a Project
Result
Automation on a small floor area is not a reduced version of a large one. The functions are the same, the address count is comparable, and the only thing that genuinely shrinks is the number of rooms.
Which means the honest answer to "is it worth it on 42 m²" is not about the area at all. It is about how many of those functions you actually want under control — and that question has the same answer in a studio as in a house.
What remains unresolved
Thirty-five devices on one TP line, in one small distribution board. The line has headroom on paper; the cabinet does not. Adding anything later means either a second enclosure or replacing devices with denser ones, and on this object the cabinet, not the bus, is what limits the next step.
A structure built to a house's standard costs more in engineering hours than the floor area suggests, and that cost is real. It is worth it when the client intends to live with the system for years and wants it to be changeable; it is harder to justify on a rental, where nobody will ever open the project again.
As with the 67 m² apartment, the address export is not published. On an object this size the address names describe individual rooms, and that is not something we put online.