Jorge Pardo, Haunch of Venison, London

Doing up a house? You could be creating a sculpture with a function

It occasionally happens that an artist's work is so puzzling, so ambiguous and sphynx-like, that you come away from it with two equally tenable views: that the art you've just seen is too subtle for you to understand, or that you do get it and it's dross. I'm still not sure which is true of Jorge Pardo's show at Haunch of Venison.

If you don't know his work, the Cuban-born Pardo occupies a slot described in the gallery guide as "crossing the boundaries of visual art with design". The questions raised by this blurring of disciplines are not new. Aestheticians have spent 200 years arguing over why (or how, or if) a Bernini salt-cellar is different from a Bernini sculpture, a Picasso ceramic tile from a Picasso canvas, a Donald Judd installation from a Donald Judd chair. To this debate has recently been added the question of how (or if, or why) any of these differs from, say, a lampshade by Tord Boontje. In a world where art can be just about anything and just about anything can be art, the status of an object is largely defined by its context. Shit in a tin and put the tin in a Piero Manzoni show and it's art. Design wallpaper and some lampshades and put them in the Haunch of Venison and ditto.

Well, maybe. Two things bother me about this view. The first is that blurring the boundaries between art and design plays into the hands of dealers with a grasp of social aspiration. The most obvious difference between a lampshade and an artwork that looks like a lampshade is that, while the first might cost £100, the second could cost £10,000. And while most people can't afford £10,000, they do need lampshades. Convince readers of Wallpaper* that what looks like a lampshade is actually an artwork and you can split the difference at £2,500, a felicity not lost on the design stores in the streets around Pardo's gallery.

The second thing that bothers me about the art /design blur is that it is easy to do and difficult to fault. In 2004, Pardo acquired a house in the Mexican city of Mérida – a dilapidated building, apparently, which he has spent the past four years doing up. Or, rather, turning it into "a sculpture that is also functional as a residence", or a "house /artwork" (that gallery guide again).

The show at Haunch of Venison evokes Pardo's house by montaging photographs of its interior on to wallpaper: the effect is rather like one of those 3-D tours of flats for sale on estate agents' websites, only blurrier. The various rooms are suggested rather than shown, so that you deduce a lobby from its tiled floor, a drawing room from a carpet. Pardo takes fragments of the relevant pattern – geometric tiling, the flock of a sofa cover – and uses them to generate kaleidoscopic, low-relief images that stand just proud of the wall. Some of these are abstract, others look like masks of the devil or a teddy bear, or like 1970s Space Invaders. You find yourself wondering whether there is some causal link between the house and these images – the devil's face has sprung from a bed, for example – although the connections feel coincidental. Above all this, at various heights, hang pretty Pardo lamps in puffball shades made of what looks like fishing twine. One of these would be lovely in my hall, although, being a work of art, beyond my pocket.

Now here's my problem with Pardo. It may be that what he's doing is satirical, nibbling away at the line between art and lampshades to suggest that both are just different forms of commodification. It's a thought worth provoking, even if others have done it before. And if you don't buy that, then you might see the Mérida House as a meditation on domesticity and domestic space, Pardo's devils and teddy-masks as a new breed of household gods. The trouble is, they feel more like doodles, as if someone has given the artist a house-sized Spirograph and left him to play. In trying to sit on the twin stools of art and design, Pardo falls between both: his work seems shallow and self-indulgent. Unless I'm missing the point, he is a sphynx without a secret.

Haunch of Venison, London W1 (020-7495 5050) to 19 April