Working from a corner of a spare bedroom or a narrow box room can be genuinely comfortable, provided you spend your budget and your planning in the right order. The trick is to treat the space as a proper workspace during the hours you use it, then let it fade back into ordinary living space the rest of the time. Get three things right — the chair, the lighting and the cables — and the rest tends to fall into place.

Start with the chair, then work out the desk

Most people buy a desk first and squeeze a chair underneath it. That is backwards. A supportive chair is the single piece of kit that decides whether you can concentrate for three hours or start shifting about after forty minutes. If your budget only stretches to one quality item, make it the chair.

Set it up properly once and your posture will thank you all year:

• Feet flat on the floor, thighs roughly horizontal, knees bent at about a right angle.
• Elbows level with, or just below, the desk surface, with shoulders relaxed rather than hunched.
• Seat depth that leaves a two to three centimetre gap behind your knees, so the edge of the seat is not pressing into the back of your legs.
• Lower back support that presses into the natural curve of your spine, not the middle of your back.
• A footrest if you are shorter than average and the chair will not go low enough.

Standard desk height in the UK is around 72 to 75 centimetres, which is why a kitchen table often works as a desk if the chair adjusts. In a tight room, look for a desk 100 to 120 centimetres wide and only 45 to 50 centimetres deep — deep enough for a laptop plus a notebook, shallow enough to leave walking room. Armrests are optional; if they do not tuck under the desk, they force you to sit further away and reach forward all day.

Light the space in layers

A single bright ceiling light is the enemy of a small home office. It puts the light source behind your head, so you end up working in your own shadow. Build three layers instead: general light for the room, a task lamp for the desk, and a little background glow to reduce the contrast between the screen and the wall.

• Place the task lamp opposite your writing hand so it does not cast a shadow across the page.
• Choose a bulb around 4000K — neutral white. Warm bulbs feel cosy but make paperwork and detail work harder.
• Position the desk so a window sits to your side, at roughly ninety degrees to the screen. Facing a window makes you squint; sitting with your back to one puts glare straight onto the monitor.
• Add a small lamp or a low-level light behind the monitor to soften the glare in the evenings.

If your only option is a corner with no window at all, accept it and compensate: a good task lamp and a brighter general bulb will do more for your energy levels than any desk accessory.

Take control of the cables

Cables are what make a small workspace feel chaotic, and they are also the easiest thing to fix in an afternoon. The aim is one visible cable coming down from the wall to the desk, and nothing else on show.

• Mount a surge-protected extension lead to the underside of the desk or the back edge, so everything plugs in above floor level.
• Use hook-and-loop cable ties rather than plastic zip ties, so you can add or remove a cable later without cutting anything.
• Run a fabric cable sleeve or a spiral wrap along the section that is visible, and leave a loop of slack where each cable meets the desk so nothing pulls taut.
• Label the plugs with a marker or a strip of masking tape — it saves ten minutes of guessing when you unplug the wrong thing.
• Keep a small tray or a lidded box for chargers, adapters and headphones that do not need to be out.

If you cannot drill into the wall — common in rented flats — adhesive cable clips and a cable spine that runs down the back of the desk leg work almost as well.

Make the desk earn its footprint

In a small room, every surface has to do at least two jobs. Go upwards before you go outwards. A pair of narrow shelves above the desk, no deeper than 20 centimetres, holds files, books and a plant without eating floor space. A wall-hung desk with no legs makes a narrow room feel noticeably wider because you can see the floor running underneath it.

Choose furniture that pulls double duty: a shallow chest of drawers with a desk surface on top, a filing cabinet that also supports one end of the desk, or a bed with storage underneath. A folding screen, a curtain on a ceiling track, or even a tall plant can separate the workspace from the sleeping area without building a wall.

Keep it comfortable day to day

Small rooms with hard floors and bare walls echo, and that echo is tiring over a full working day. A rug, a curtain, a fabric pinboard and a couple of soft furnishings will absorb enough sound to make calls feel less shouty.

Set your screen an arm's length away with the top of it at roughly eye level — a stack of books under a laptop works fine. Then build a two-minute reset into the end of each day: chargers into the tray, papers into one box, chair pushed in. A workspace that takes two minutes to tidy is one you will actually tidy, and that is what keeps a small office feeling like part of the room rather than a takeover of it.