Come up to the roof of the erstwhile pub I bought and renovated with my husband, Olly Hoeben, 11 years ago, and you will see his dream of 50 years made real. Around the flat, decked roof with its expansive views of London, and a sky that seems so close you could touch it, are three timber, glass and lead units, precisely designed to look and feel like ships' cabins. But why cabins at the top of an urban building? The reason is found in Olly's formative teenage years. Aged 15, he went to sea as a trainee able seaman. It was what many working-class lads, growing up in Amsterdam in the poverty-stricken years immediately after the war, did to earn a living.
So, at an age when most of our kids are acting out teenage rebellion and contemplating GCSEs, Olly was crossing the seas in cargo ships. He was the youngest crew member with "45 fathers who were strict but also protective and played jokes on me".
He got an informal education in many things from creating intricate knots, handling winches and being helmsman, to geography, seafaring and partying in the ports where they docked, as the ships journeyed to South America, South East Asia, India, Africa and the United States.
Yet Olly's enduring memory is of the cabins which were his retreat from the activity, the noise, the constant activity of ship life. In these cabins he felt "tranquil and secure". It was there that he had the peace to enjoy a stash of books from the ships' library, to write to his mum and to reflect on all he was experiencing. There too he gained much pleasure looking out of the porthole at the ever-changing sea and sky. The most memorable occasion, Olly tells me, was when the boat he was on, which was transporting 250 bulls to Peru, hit the warm Humboldt gulf. Plankton rose to the surface creating a feeding ground for every kind of bird, including thrusting pelicans. The sky was transformed into a black mass of beating wings, while whales rose high in the water.
Olly had quit sailing by the time we met, and when he came with me to England his work was in films, photography and running a small business. But he never lost his passion for big boats, the look and feel of them, the gear on board, the safe, cosy feeling that cabin life engendered.
We could not pass a chandler's merchant on trips to the seaside without Olly nipping in to buy oversized hooks, rope, giant wood and brass pulleys, which were then positioned around our home as ornaments. In the sitting room a giant brass porthole has rested against the wall for many years (I refused to have it inserted into the ceiling). On visits to auctions and markets Olly would impulsively snap up hefty copper and brass ships' lights. All of them were beautiful objects, but they just didn't fit into the design of our home and so ended up being stashed away.
He tried all kinds of ways to create cabin-like spaces in our various homes – in one case a rectangular hole in the living room wall hollowed out and fitted with a mattress so you could lie and gaze out through the windows at the night sky. But mostly his efforts were thwarted.
Then early last year Olly bought a book about a Dutch whale ship with, as he put it, "fantastic drawings including a ship's cabin". That inspired a series of rough sketches on the back of an envelope, accompanied by murmurs about doing something with the cubby holes in our pitched roof, which were mostly used for storing junk, and transforming my dingy, makeshift workplace.
As Olly translated his sketches on to a drawing pad with architectural lines and measurements it became evident that these were designs for cabin-like units.
My first reaction was "leave the roof alone". It is the place I grow my salads and herbs; huge bamboo plants curve decoratively around our outdoor shower, and the decked area is perfect for putting out reclining chairs and hammocks and inviting friends to enjoy a chilled wine on a warm evening.
But Olly was adamant I need lose none of this, so I thought "why not let the man have his dream?"
Andras Kaldor, an architect friend who lives near the harbour in Dartmouth, and who was in tune with Olly's marine thinking, turned the ideas into formal drawings, incorporating some creative thinking of his own. These involved raising ceilings where possible, building timber dormers out on to our sizeable decked roof, and fitting large wood and glass doors .
The cabins would incorporate the plastered walls and wooden floors already there. Outside, the walls and roofs would be clad with lead. Kaldor applied for planning permission, which Islington Council, efficient to the last, gave without trouble – on condition that the cabins were not visible from the street.
Olly would project-manage, and who better to create these idiosyncratic structures than Olly's "stepson" Casper, who lives in Amsterdam and renovates waterside buildings? Casper and his mate Juriaan worked like demons creating sturdy pine frames for the dormers; the only time they had to stop was when a consignment of recycled teak which Olly had ordered from Indonesia arrived full of woodworm and nails. It was supplemented with iroko wood bought in London. "The boys" moved on to cladding the windows with wood before fitting tempered glass panes, struggling slightly with the sideways triangle window in my office.
If the units were to function as workplaces, they needed insulation to prevent the cold coming through the roof. Olly had rolls of sheepswool delivered from a company in the Black Mountains. It was treated with the natural mineral compound borax, which insects dislike: the last thing I wanted in my office was the constant sound of tiny, scuffling creatures.
The wool was sandwiched between the roof and and plasterboard, creating a thick, protective layer, and the board was plastered over.
Meanwhile Jules Darker, another friend and skilled craftsman, spent many long hours crouched on the roofs of the structures fitting lead sheeting with corrugated ridges to let water drain off. Sheets were spread around the outside walls and the finishing off around the top edges was done with the delicate touch of an embroiderer.
We were nearly there, but not quite. Two days later Olly arrived with a porthole for each of the three cabins, and one for the adjoining outside loo. They were transformational. Once fitted, they made the top of our house looked uncannily like a ship; you could fling open the doors and walk out on to the deck, while the hefty parapet at the edge of the roof, with its view of London's skyline – a view that will, in time, incorporate the tallest building in Europe – gives the impression of coming into port.
So there the cabins were, ready for use. Mine, fitted with a desk and floor-level cupboards, is a delight. I am surrounded by glass, which, as well as letting in plenty of light, offers some fine views, including one looking out onto the Christopher Wren tower on top of the church opposite.
The cabin created for our younger son, Cato, who is an electronic music composer, creating scores for films and advertisements, is a recording studio fitted with extra insulation and sound-proof glass. After years of setting up his equipment here, there and everywhere, he at last has a dedicated space for the tools of his trade.
Olly's cabin is the largest. As well as an open workroom where he does his photographic work, there's a mini-kitchen where we have breakfast with the sun is pouring in, and which will be great for rooftop meals in the summer. There's also a retreat area with a place to flop, where he goes to read, or be transported back to those years at sea.
And he is endearingly delighted. "It has come out just as I wanted," he says. "It brings back the best of the memories of feeling secure and cosy as a young boy at sea. There are seagulls in London so I still have birds to gaze at, and there are wild winds that rattle the tops of the trees, there's lashing rain, and there's a vivid spread of sunlight which I watch through my porthole."
And now it is all done I am entirely won over. The cabins have added a new dimension to the house, as well as giving us much-needed work areas, and they're beautiful. Not only that, but their presence is entirely appropriate given that our building is called the Crown and Anchor.