In bathrooms, compact is the big concept for 2009. Because we’re not upsizing by moving house, designers are devising ways of making our present properties work harder, including tiny additional washrooms in underutilised nooks around the home. With specialist fittings and clever decoration, these miniature rooms can seem surprisingly spacious.

Howard Birch, director of Aston Matthews, which sells exceptionally chic bathroom fittings, reports a rise in customers installing small bathrooms this year. “People often create an ensuite in a small or awkward space, possibly a box room,” he says. “As a result, space-saving fittings are much in demand.” The white ceramic Ergo range is Birch’s compact bestseller, including a corner loo and a 46cm wide corner basin, so small that they can fit side by side on a one-metre wall (basin £148, WC £240; 020 7226 7220, astonmatthews.co.uk).

Villeroy & Boch, which produces simple, stylish tableware, has its own spin on titchy bathroom kit. The new Memento handwash basins (40cm x 26cm) are tiny lozenges of white or black ceramic with a handrail set beneath (from £416; 020 8871 4028, villeroy-boch.co.uk ). In the same space-saving spirit, the Giralda range, by the Spanish manufacturer Roca, in white ceramic and pale maple wood, includes a corner basin (50cm square, from £163) and a slim mirrored corner cabinet to hang above it (95cm x 40cm, from £392; 01530 830080, roca-uk.com).

For a budget option, go to Bathstore, where the tiny Savoy corner basin is £99, down from £149 (bathstore.com), or try Homebase’s titchy Peru cloakroom basin. It’s £69, or £364 with matching loo (homebase.co.uk).

You would think that one item unequivocally banned from the diminutive bathroom would be the freestanding bath. Yet such is our addiction to a good wallow that there are several short tubs designed for smaller rooms. Regular baths are 170cm or 180cm long, but the Aston Matthews Verona cast-iron roll-top is just 154cm long (£1,045; details as above). Another gorgeous freestanding tub is the Delicata, from BC Designs. At 152cm long, it is a sculptural contemporary take on the Edwardian slipper bath (from £2,415; 01206 827100, bcdesigns.co.uk).

Though a freestanding bath is the traditional object of bathroom desire, back-to-wall baths are far better for space-saving, and the new asymmetric designs are best of all. Ideal Standard offers the Concept, a wall-hugging unit with an undulating side that curves inwards towards the taps to leave room for a hand basin. It sounds bizarre, but has pleasantly streamlined, flowing lines (170cm x 70cm at its widest and 55cm at its narrowest, £315; 01482 346461, ideal-standard.co.uk).

At B&Q, the Barcelona is a compact, asymmetric acrylic tub that tapers from a width of 75cm at the head to 50cm at the taps (169.5cm long, £357; details as above). A similar product, newly launched by Villeroy & Boch, is the Subway P-Shaped shower-bath, which incorporates a smart glazed shower stall in the loop of the P (170cm x 75cm at its widest and 55cm at its narrowest, from £1,250; details as above).

If you can do without a tub, but want a dash of opulence in your teeny bathroom, check out Matki, a company that specialises in squeezing beautiful glass-walled showers into the most implausible crevices. The tiniest examples feature a shower head tucked into a corner, enclosed by an elegant curved glass screen (from £919 for the Original Radiance curved corner surround, including enclosure, shower tray and waste; 01454 322888, matki.co.uk). Alternatively, Bathstore.com stocks the Atlas quadrant, a curved glass corner shower stall with sliding doors (195cm high, was £699, now £449).

Once you’ve installed your Lilliputian suite, how to decorate? In a tiny space, design must be unfussy — no spriggy floral motifs or mosaic tiles. Blocks of colour or scaled-up patterns will work best, and continuous wall coverings such as Corian can be more forgiving than traditional ceramic tiles. Best known for its ubiquity in high-end kitchens, Corian also lends a warm, contemporary look to bathroom walls and floors, vanity units and bath surrounds. It’s made to order in 100 colours. It’s fairly pricey — from £250 per square metre for bathroom wall cladding — but in the quantities needed in a compact room, it may be the luxury you decide to afford (0800 962116, corian.co.uk).

If you prefer natural materials, walls in limestone or sandstone cladding might appeal. Stone Age offers textured finishes for bathroom feature walls — a subtle decorative touch that works superbly in a small space. Glacier Effect is a rough, rocky surface, finished by hand, on its bestselling Piedra Plana limestone tiles. Prices start at £73 for each 40cm x 40cm x 2cm tile (020 7384 9090, estone.co.uk).

Working to a tighter budget, a big-print wallpaper can be excellent in a small-scale bathroom, as long as the product is designed for a steamy environment. Pallade, from Graham & Brown’s Contour collection, is a kitchen and bathroom paper with an oversized damask motif set against a black background (£20 per 10-metre roll; 0800 3288452, grahambrown.com).

Which brings us to hue. The default option for a bathroom is white, with perhaps a dash of beach-hut blue, but this year black has crept unexpectedly into the look books. Johanna Bush, bathroom specialist at the luxury interior design firm Evitavonni, says that black is the new white, especially for pocket-size bathrooms; in fact, it is this year’s “must-have” colour.

There you have it, then. Black is the new white for pocket-size bathrooms. Moody glamour it is. And I bet they’re easier on the Domestos, too.

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