David Hockney described it as a great operatic experience.

For years, I have been meaning to visit Dennis Severs' house at 18 Folgate Street. One day soon, next time I have visitors, and really, shouldn't I book in advance, all those excuses that meant yet another year passed - and Dennis Severs died - and I still hadn't got round to doing something that I really, really wanted to do, that is less than a hour's tube ride from home.

And today, at last, I put on my coat, queued for half-an-hour in the icy-cold drizzle ... and stepped back in time into one of the most strangely moving historical experiences that I have ever had.

This house made me shiver. (There are pictures here and links here and here will take you to two beautifully-written accounts by the author of Spitalfields Life.)

You are asked to imagine that this is the house of a fictional family of silk weavers ... you are just too late, because they have just stepped out of the room. Leaving a crumpled napkin and a glass of wine, half-a-cup of tea, a half-eaten breakfast, a child's shoe on the stair, tumbled beds and a chamber-pot that needs emptying. (I didn't investigate too closely.)

Indeed, if you investigate too closely - as if you were in a museum - you will find yourself peering at sardonic little notes from Dennis Severs, pointing out that if you are looking too hard, then you are missing out on the essential experience. This is not a house that needs a guidebook.

Fires are glowing, candles flicker, stairs creak, footsteps pass on the pavement outside and the clock on Hawksmoor's nearby Christ Church strikes the hour ... until you're hard put to say what is real and what is theatre and what is your own imagination. I caught myself looking into a tarnished mirror for a glimpse of what might be happening behind me.

I warmed my hands at the fire in the basement kitchen, where somebody really had been baking for the last two days ... there was bread toasting in front of the fire, Welsh cakes on a griddle, jellies glistening on the dresser, a scent of oranges and cloves and mincemeat. If there were ghosts here, they were cheerful and busy.

But up in the icy-cold garret, where ragged, grey shirts were strung on a line to dry in front of a fireplace of cold ashes ... that's where I really shivered because the walls seemed to exhale the misery of generations of poverty. I don't know who really lived here. It doesn't matter. There are streets of houses like this in Spitalfields, layer upon layer of history. (In the cellar you can see the real remains of a medieval leper hospice.)

I dawdled until I was the last one there and wandered through the house in silence on my own. Then chatted for a few minutes to the custodian who told me that for several months he had actually lived in that attic. There is always somebody living here. Take your time, he said, as he moved around the front parlour, trimming candle wicks, you're not in anybody's way ...