Dickens wrote in a study he engineered for quiet. The desk faced a window, the door kept the house out, and the city itself waited for the afternoon.

The Direct Answer
In a quiet study at a desk set before a window.
At Tavistock House he added an extra door to muffle noise, a detail noted in Mason Currey's Daily Rituals.

A Room Built for Silence

Dickens needed absolute quiet to work, and he went to real lengths to get it. At Tavistock House in London he had a second door fitted to the study to block the sounds of the household, turning the room into something closer to a sealed box. The desk sat in front of a window so he could glance up at the light and the street while he worked. He kept the same hours there every day, roughly nine to two, and the household learned that the closed study door was not to be tested.

The room was arranged as carefully as the schedule. A fixed set of ornaments stood on the desk in their assigned places, and the writing surface itself faced the window rather than a wall. He wanted the same view, the same objects, and the same silence each morning, so that almost nothing in the environment changed from one working day to the next.

He didn't only write in London. From 1856 he owned Gad's Hill Place in Kent, a house he had admired as a boy and finally bought as a successful man. He wrote there too, sometimes in a small Swiss chalet set up in the garden across the road, which he reached by a tunnel he had dug under the highway. Up among the branches, with the windows open, he had quiet of a different kind, the country sort, with the fields of Kent instead of the London street below.

And the City Counted as a Workspace

The study was only half of it. After two o'clock Dickens went out and walked, and the streets did real work for him. They supplied the faces, the grime, the signboards, and the noise that ended up in the novels. He read London on foot the way other writers read books, and the prowling fed the writing as surely as the desk did. The night walks, when insomnia or a deadline drove him out, could run far longer than the daily twelve miles.

So the workspace had two halves that depended on each other. The sealed study gave him the silence to get words down in the morning, and the open city gave him the raw material to keep the well full. Take either one away and the routine probably falls apart, which is why both the quiet room and the long walk show up in nearly every account of how he worked.

It's worth picturing the contrast. The study was hushed, ordered, and shut tight, with the same ornaments on the desk and the same view from the window. The streets were the opposite, crowded and filthy and alive, and Dickens needed both. He wrote in the calm and refilled in the chaos, then carried the chaos back into the calm the next morning and put it on the page.

Thinking whereof, he walked about the black streets of London, fifteen and twenty miles, many a night when all the sober folks had gone to bed.

Charles Dickens on writing A Christmas Carol, letter to Cornelius Felton, 2 January 1844

Quiet to write, then the loud city to gather from. For how the desk hours and the walking hours locked together, see the full Charles Dickens writing routine.

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