In short: scenes first, fittings second
Lighting is planned from what you do in each room. List the activities for every room, work out what light each one needs, group it into circuits with their own control, decide where and how they are switched, and only then choose the fittings. A central pendant can be part of the scheme, but it does not replace light for reading, for a worktop or for a film night.
All of this is needed by the start of first-fix electrics. Once walls are closed, adding a circuit or moving a switch means chasing finished surfaces.
How to write the list of scenes
Take a living-dining room with an open kitchen, like the one in the Urgel flat in the Eixample. Dinner: dimmable light over the table and a little background. Film: only soft light on walls or shelves, nothing reflecting in the screen. Guests: everything on, but not at full. Cleaning: all general light at maximum. Reading: a floor lamp or wall light by the armchair.
The bedroom has its own: reading light on each side of the bed, switched separately; light in the wardrobe; a floor-level night route to the bathroom that will not wake your partner. The hallway needs two: normal and night. Write all of this on the room plan, directly over the furniture layout.
Layers and circuits
Layers come out of the scenes. General light gives an even background. Task light covers places where something happens: the table, the worktop, the mirror, the armchair. Accent light brings out a textured wall, a painting, a niche or joinery. Orientation light is for night-time and circulation. The kitchen and its three types of light have their own article.
Every layer you want to switch separately becomes its own circuit, meaning a separate line or control channel. More circuits give more flexible scenes but more complicated control; in a living room five or six are usually enough.
Light and furniture: one plan, one version
Light points are fixed after the furniture layout, not before. Move the dining table forty centimetres and the pendant hangs off-centre. A mirror opposite a spotlight throws glare back into your eyes; a TV facing a window and a ceiling light fills with reflections. Built-in wardrobes with internal lighting need power inside the carcass.
If furniture changes during the project, check the lighting too. The lighting plan and furniture plan must describe the same interior and the same version of the layout. Think separately about maintenance: where the drivers for LED strips sit and how to reach them without taking the ceiling apart.
Control and compatibility
Decide where each circuit is switched from: at the room entrance, on both sides of the bed, two-way switching in the hallway. Wherever dimming is wanted, the dimmer, the fitting and its driver must be compatible, otherwise the light flickers or hums. That is confirmed by the electrician or lighting specialist, not the person selling the fittings.
If scenes will be triggered by a single button or from an app, the electrician runs a neutral to the switches and fits deep back boxes. Smart-home infrastructure during a renovation has its own articles.
Parameters worth knowing
Colour temperature: living spaces usually get warm light around 2700 to 3000 K, kept the same within a room, otherwise the ceiling and the shelf strip end up different shades. Colour rendering: the higher the index, the more natural wood, stone and skin look; for a home a CRI of 90 or above is a sensible target. The beam angle of a spotlight decides whether you get a pool of light on the wall or an even wash.
Most important: do not aim directional light where you will lie or sit looking up. A spotlight above the bed or the sofa shines straight into your eyes. Do not buy a fitting from a photo alone: ask for the data sheet.
Samples and the final scheme
Where possible, see how the chosen light falls on the project's real materials: parquet, paint, stone, fabric. The same strip looks different on oak and on white plaster, and a phone screen will not show it.
The outcome is a lighting scheme coordinated with the furniture design and the budget, with the control for each circuit specified and open questions flagged before the work that depends on them. We go through that scheme with the electrician before first fix, so changes happen on paper rather than inside the wall.