Technical room in a detached house: what goes where?

Where do we put all the technology in a house built in 2025? This is a question that electrical planners, architects and building owners have to address at a very early stage. The solution is, of course, the plant room. We have summarized all the details and special features of this very important room in a house in this article.

Why are we so good at this topic? In recent years, we have technically designed and planned over 170 individual smart home houses and smart home villas and the technical room played a key role in the equipment. The technical room and its equipment is an important part of electrical planning – see our article Electrical planning in 10 steps: detached house & apartment.

Many architects and building owners still underestimate the need to plan for a generously sized utility room in 2024. However, it is almost self-explanatory that this is indispensable in buildings such as individual detached houses, which leave nothing to be desired in terms of comfort, safety and energy efficiency.

The technical room is the room in every house where all the technology is housed. Concentrating all the technology in this room is a conceptual approach. In an upmarket Smart Home detached house or a smart home villa is equipped with significantly more technology than in a conventional house.

The technical room contains the following building services:

Heating system – heat pump with pipes
Hot water storage tank for baths and showers
Ventilation system for all rooms
Electrical distribution – electrical control cabinet or several control cabinets (KNX)
Battery storage
Inverter of the PV system
House connection box – power line
Telecom connection – fiber optic or copper lines
Network technology – 19-inch distributor for indoor and outdoor networks
Cold water connection
Waste water connection

The typical supply lines for the building, such as the electricity connection, domestic water connection, waste water connection, telephone line, TV cable and telecom fiber optic connection, also come into this room. The Multi-branch house entrythrough which the pipes enter the house is therefore also located in the plant room.

It is often planned for the side of the house closest to the street, as this is the shortest length of pipe for the supplier and the house connections can be installed as cost-effectively as possible.

The transfer points of the utilities (electricity: house connection box, water: water meter, telecommunications: house transfer points) are also located in this room.

In smaller houses – such as terraced corner and mid-terraced houses and houses built by developers – the utility room is often a shared room with the utility room. This means there is significantly less space available for modern technology.

Which trades come together in the plant room?

Where in the past – from the 1960s to the 1990s –there were just a few pipes running together and a small box on the wall with a few electrical fuses, things look much more complex in new builds today: In addition to the heating system in the form of a heat pump with hot water tank and a whole series of valves and expansion tanks, the heart of the electrical installation is located in the plant room: the electrical control cabinet.

In more and more houses, especially new-build detached houses, the central ventilation system is also being added. It also requires space with its pipes and ducts that run through the entire house from the cellar to the roof.

Electrical engineering with networking and home control (KNX, DMX, DALI, ModBus etc.) and network technology (TCP/IP) or WLAN
Photovoltaic system with connection to battery storage including inverter
Security technology (security against burglary, burglar alarm center)
Multimedia technology with multi-room audio
Heating technology
(Cold) water supply and water treatment (descaling optional)
Waste water technology (waste water lifting unit or sewage lifting unit optional)
Ventilation technology with filter system
Air conditioning (air conditioning optional)

Which cables come into the plant room?

Firstly, there is the water supply for hot and cold water with an additional pipe for the circulation line. The latter ensures that the hot water can never cool below a certain temperature and that hot water is immediately available on demand when a tap is opened in the house.

In addition, there are the waste water pipes from all the toilets, showers, washbasins and sinks in the house, which all converge in a waste water pipe in the utility room. The latter runs into the house’s waste water connection, which is located on one side of the utility room.

As underfloor heating has been a standard feature for some time, the supply and return pipes are also located in the plant room.

With a much smaller diameter but all the greater number, the electrical cables of the entire house also run together in the plant room. Or rather: this is where all the electrical cables originate, which are then distributed to the individual floors of the house via the technical shaft.

The ventilation system takes up special space in the plant room and usually also has pipes with a larger diameter due to sound insulation: Modern systems have pipes up to 20 cm thick at the inlet and outlet to the system itself.

Waste water connection also in the utility room?

If the utility room is properly planned, then the connection to the wastewater network will also be in this room. After all, all the wastewater pipes in the house end up in the utility room, which is usually located in the basement.

Technical room: How big should it be?

House type

Total living space

Technical room Size

Detached house

up to 220 sqm

8 to 10 square meters

Apartment building

up to 600 sqm

15 to 20 sqm

Terraced house (corner, center)

up to 120 sqm

4 to 6 sqm

large villa

up to 850 sqm

12 to 15 sqm

Ventilation system: Space requirement in the plant room

Today, ventilation systems are almost a standard feature in new-build homes. And it must be installed in the plant room, as it takes up a lot of space with its thick pipes. The ventilation system is controlled electrically via sensors or switches/buttons. It is directly connected to the (KNX) electrical engineering of the house.

In our experience, the space required is often underestimated. Depending on the type and equipment, at least 1 to 2 square meters of floor space in the plant room should be planned for the ventilation system.

Technical shaft: All pipes to the technical room!

In the planning phase of a house, the technical shaft and its size are very often determined. If the architects do less planning and more decisions are made on site (at the construction site), several small “service shafts” are often created in different corners of the house.

The disadvantage: the pipes for the individual trades in the house run in different shafts and have to be concealed later by means of “trunking”. It is much easier to define a central technical shaft of sufficient size and dimensions right from the start. Why is the technical shaft so important? All supply lines run through the technical shaft and end in the technical room.

The picture below shows the pipes for heating, ventilation, water, waste water and air conditioning, all of which go into the technical shaft.