For many decades, the rural English museum was a typology untroubled by architects. All that changed, of course, with the idea that a museum could be a destination in its own right, a piece of architecture equal to or even exceeding the worth of the collections within.

Nestled in the rolling landscape of East Sussex, the Ditchling Museum of Art + Craft seemed even less concerned with appearances than most. A former village school, bolstered by the gentle accretion of two decades, the Museum brought together art, crafts and design, building on the village's longstanding association with some of the key figures in early twentieth century applied art, design and sculpture.

Last week, the overhauled museum was officially opened by Sir Nicholas Serota. Re-built, re-hung, re-organised and utterly transformed, the new museum buildings were designed by Adam Richards Architects, funded by the Heritage Lottery Fund. They were five years in the making, following a competition win in 2008.

Richards' approach is one of unification and restoration, with new build carefully sandwiched between existing structures. The museum used to be entered via St Margarets churchyard but Richards, together with project architect Sam Dawkins, flipped the orientation, transforming a carefully restored former 18th cart lodge into an entrance, café and shop, leading through to the re-ordered main gallery via a terracotta clad link building.

Richards describes the commission as a 'great treat', and the architecture is domestic in scale and meticulous in its details, despite the tight budget. He speaks of trying to 'imbue the museum with the spirit of its collection,' a process that begins simply and honestly with the restored cart lodge, stripped back to bare bones and rebuilt - 'nipped and tucked' - into a sort of rustic pavilion, the first floor cut away to reveal the beams above and a window placed just so to give a view out onto the church. Richards visited a huge variety of museums to research the job, from Kettle's Yard in Cambridge to Chipperfield's Neues Museum in Berlin, but in the end it's the vernacular of West Sussex that wins through, as well as a palette of mild, earthy colours - greys, browns and reds.
The domestic scale is carried through the new link building, up a tapering set of concrete stairs and clad externally in terracotta tiles. From here, one enters a new gallery building, a zinc-clad, barn-like form with a single tall window overlooking the village pond. Here the architects have built a tall display cabinet - a wunderkammer - that hints at the collection within and its connection to the life of the village.

The pivotal Ditchling artist is of course Eric Gill, the deeply complex and devoutly Catholic letterer and typographer. Gill came to Ditchling in 1907, and from then onwards, the small village became home to a group of artists and craftspeople who stayed true and loyal to the ideals of the Arts and Crafts movement. Often devout and other-worldly - Gill established The Guild of St Joseph & St Dominic in Ditchling and ritual, liturgy and prayer were integral to their lives - and certainly artistic and eccentric by modern standards, the artists were also devoted to the highest levels of craftsmanship and quality.

The main gallery, planned and laid out by Richards with signage and way-finding by Phil Baines, sets out the lives and work of the main players in the community - Gill, Edward Johnston, Hilary Pepler, David Jones, Desmond Chute, Philip Hagreen, Edgar Holloway, Ethel Mairet and Hilary Bourne (who set up the museum in 1985).

Perhaps they would have remained marginal but revered figures in art history, were it not for their impact on the look and feel of modern life. Edward Johnston, who had taught Gill and arrived in Ditchling in 1912, is best known for shaping the typography and identity of the London Underground, having been commissioned by Frank Pick in 1913, while Gill's typeface, Gill Sans, is still widely used.

The Museum of Art + Craft feels simultaneously timely and old-fashioned, replacing the ad hoc and ramshackle arrangement of the original buildings with sleeker, crisper, Farrow-and-Balled version of the original, filled with the analogue totems of the digital era - letter-pressed type, carving, craft, honesty and virtue. The printing press itself, once the hub of the community, is given reverential placement, an altar piece paired with alcoves containing the tools, materials and output of the Ditchling Press.

Richards and his team use architecture to hint at the divine within the ordinary, giving a modern, largely secular, audience just a taste of the motivations and obsessions that shaped a very singular community.