This year's Summer Exhibition at the Royal Academy was themed – by David Hockney, no less – on drawing, a discipline in which architects excel. We discovered the delights of Gallery VII
Drawing is the dominant theme at this year's Summer Exhibition at the Royal Academy. Chosen by the artist David Hockney to cover the whole pantheon of art, the theme nevertheless has a special importance to architecture. The architectural drawings in Gallery VII have been selected for their sheer showmanship and the more down-to-earth skill of realistically conveying what the finished building will look like.

Not surprisingly, they range from the way-out and avant-garde to the traditional and even old-fogey. At one end of the spectrum is the crystalline vortex that underlies Grimshaw's design for the Education Resource Centre at the Eden Centre in Cornwall. The timber roof structure, devised with artist Peter Randall-Page and engineer Anthony Hunt Associates, was inspired by a natural pine cone. Its mesmerising digital image was worked up by a separate team of Jason Ahmed at Grimshaw, Chris Williams of the University of Bath, Sean Hanna of University College London and Robert Aish of computer software firm Bentley.

At the other end of the spectrum, Gallery VII also features punctiliously detailed perspectives that could only have been rendered by draftsmen with their sleeves rolled up, slumped over large drawing boards.

Eric Parry's view of a new pavilion next to the St Martin's-in-the-Fields church is an architectural variant of Pointilism – and fits the latter bill so well that it won the £1000 award of the Worshipful Company of Chartered Architects. The style of presentation does not necessarily indicate the style of architecture: in Parry's case, the highly traditional rendering was no doubt suggested by James Gibbs' sumptuously ornamented classical church rather than his modest drum-shaped pavilion to be built next to it.

The architectural hanging committee of Piers Gough, Eva Jiricna and Ted Cullinan even found space to fit in one or two rough-and-ready architects' hand sketches. An annotated felt-tip-pen sketch by SOM's Larry Oltmanns of his Pribinova riverfront flats in Bratislava on the Danube has a down-to-earth immediacy that gives a realistic visualisation of the building's scale, modelling and texturing. But just as natural plant species are threatened by GM crops, it's worrying that this basic architectural skill is being superseded by CAD drawing.

Looking beyond presentation to the actual architectural projects, it's worth remembering that the Summer Exhibition is largely a Salon des Refusées. Many of the projects revealed for the first time are competition entries. But they are not the winners, but the also-rans fondly nurtured by their creators.

True enough, these can be quite inspiring, and not just for their presentation either. David Marks of Marks Barfield Architects is justly proud of his competition entry for the Prince Salman Science Oasis in Riyadh, Saudi Arabia, inspired by classical Islamic geometric patterns and futuristic DNA spirals. Sadly he was less able to predict the 9/11 terrorist cataclysm in New York, which effectively stymied ventures in Saudi Arabia.

  • Summer Exhibition 2004, Royal Academy of Arts, Burlington House, Piccadilly, until 16 August.