If you happen to be walking down the Canongate in Edinburgh’s old town in the next few days, do not be surprised if you see someone hurry off into Crichton’s Close, a vacant look in their eye. It might be one of the members of the newly remodelled Scottish Poetry Library, and what you might easily take for vacancy is in fact exhaustion. And relief. And – one hopes – a feeling of pride.

It is only ten days since the official opening of the enlarged building, and the rigours of the past few months will take longer than that to fade. Not that the director, Robyn Marsack, librarians and other members of the ten-fold team are complaining. The library was always a delightful haven, but now that it has been extended, with more windows, shelf space and rooms, it is arguably one of the most attractive modern designs in the medieval heart of the capital. This is not the place to rehearse one’s fury over some of the city’s proposed new developments; suffice to say, council members would do well to pore over this bijou nordic edifice, which fits as naturally into its surroundings as a goldfish into a pond.

I missed the grand opening, but on the bright mid-morning when I was shown around, the place was dancing with sunlight. As Colin Waters, my tour guide, and the library’s communications manager, said, “Now when you step inside, your retinas shrink – and your heart expands. As I like to say, light is the new member of staff.” It is the sort of response working in such a place inspires.

What is perhaps most interesting about the library’s makeover is that Robyn Marsack took a difficult decision to expand in the current location, rather than allow the ever-growing library, and its multiplicity of functions, to sprawl into new locations. She knew the idea would not be met with universal approval, but she went ahead anyway. Like the library’s founder, Tessa Ransford, she has proved herself dauntless and wise.

The remit for the enhanced building was broad, though its main aim was simple: to be more enticing to readers. When the library was first opened in 1999, it was assumed that its size would suffice for the next ten years. By the time it closed for rebuilding, the place was so cramped the books were gasping for air. The lesson of that brief ten-year plan has been learnt. At the turn of the millennium it was blithely assumed that money would be easily forthcoming to help deal with the next generation of poets and readers: lottery money was abundant, there was a new Scottish Parliament, and the spendthrift Blair years were in full swing. Then the credit crunch arrived. By the time the library’s buttons were popping off under the strain, there was far less public money on offer. Yet in the intervening years, what had begun as a library with two members of staff, had evolved into an arts organisation, whose outreach to schools, care homes, and international readers via social media and podcasts, was infinitely more complicated. Not to mention the 45,000 books and magazines and journals it houses, and many more still to come.

The future is uncertain. Just as nobody in 1999 could predict the radical changes in communications and publishing we’ve recently witnessed, we are no more likely to be clairvoyant about the way things will be in 2030 or 2040. With that in mind, the design of the library is deliberately flexible, able to be adapted to accommodate the years to come, even though no-one knows what shape they will take.

Meanwhile there is a children’s corner, complete with a cuddly sheep named William Dunbaa; a room where you can listen to cds and old vinyl recordings of poets’ works by themselves, or others, such as Orson Welles reading Walt Whitman, or Alec Guinness’s rendition of T S Eliot; and, visible from the street, there are row upon row of airy shelves where books are begging to be picked out and read.

There is the troublesome issue of a £40,000 overspend, which funds still must be raised. But that seems to be the only problem – and a temporary one at that – in an otherwise enlightened endeavour.