'Geometry - it's almost foolproof!" says the interior designer Jo Hamilton. My heart sinks. When a celebrity chef tells me that a recipe is foolproof, it always goes wrong. Now there's a celebrity designer telling me I can play around with geometric patterns. What if I end up with a room that looks like a breeding colony of chevrons ran amuck?
"Geometrical patterns are supercool," Hamilton adds. "The lines are so simple that they're very calming, but they're also interesting to look at. You get lots of drama without looking naff."
When I voice my concerns, Hamilton admits I'm not alone. Combining geometrics is a pretty scary thing to do. "Remove the idea that you've putting geometrics, layer on layer, and just think of them as patterns," she explains. "If all the patterns are on the same scale, then they will fight against each other. You need to divide them into small, medium and large."
This, she assures me, is a fail-safe approach to using pattern. I'm calling it Hamilton's Rule of Three.
When you look at Jo Hamilton's designs, you can see what she's talking about. In a Greenwich Village apartment in New York, she's combined Andrew Martin's Biography wallpaper, a grid of grey squares, with a big bold diamond patterned rug.
The shapes on the rug are echoed in the bare bones of a geometric coffee table, a chunky piece in marble and bronze that she commissioned to fit the room.
Between the long tall windows is a modern mirror made from a grid of antique glass. The mirror references the lines of the windows, and also the wallpaper pattern. "The window frames were the starting point for the room," she says. "The owners loved the building, which has beautiful architectural mouldings, but I didn't want the room to feel twee."
Here, you can see Hamilton's Rule of Three in action. The pattern on the rug under the coffee table is small and detailed; the upholstery on the chair and cushions has a medium-sized pattern; while the geometrics on the rug under the bed are large. "There's a lot of drama, but it doesn't scream and shout."
For geometric designs at a reasonable cost, she recommends the British company Andrew Martin. They don't have a showroom in Ireland but you can buy wallpaper (from around €95 for a 10 metre roll); fabrics (€24 to €178 per metre); and cushions (from 53 plus fabric) from their online store.
The atmosphere in the room, as requested by its owners, is calm. Hamilton achieved this with a muted palette, basically shades of grey, enlivened by teal lampshades and velvet cushions. "When people ask for a relaxing atmosphere, I always think about cooler, calmer colours," she says.
Hamilton's design for a lounge in Hamstead, London, followed a very different brief. This is an exuberant, extrovert, and very expensive ensemble. "The story was set by the rug," she says. "The owners just fell in love with it."
It comes from the Rug Company, where prices range from €422 for a 6x4ft rug to €1,663 per square metre. If you want to shop more locally, the Irish companies Rug Art and Ceadogán have plenty of geometrics on offer. Both are taking part in the interior design event House at the RDS at the end of this month. Once the rug had been chosen and made to order, the challenge was to design the room around it.
"With any interior, any big statement that you make needs to be balanced. You don't want to come into a room and feel that everything is shouting at you at once. Some pieces can raise their voices, but other pieces need to whisper."
To create a sense of equilibrium in the room, Hamilton's Rule of Three swings into play again. The large pattern of the rug is balanced by a medium scale pattern in the mirrors on either side of the fireplace, contrasted with a much smaller pattern in a pair of matching cabinets below. Both mirrors and cabinets come from Christopher Guy. They're modern, with a 1930s flavour.
One simple and effective way of introducing geometrics is by using wire-framed light fittings. These enclose a pendant bulb like the skeleton of a lampshade or the outline of a cage. "The shape changes as you move around them and they cast wonderful shadows," says Hamilton.
She's also a fan of coffee tables with geometric frames. The Eichholtz Connor coffee table (€2,367) from Sweetpea and Willow is a glitzy example, but you can buy much cheaper coffee tables based on a similar notion. "Because they're not too solid they make the space seem bigger," she says. "You can see the rug or the floor beneath them and the more floor that you can see, the greater the sense of space."
Jo Hamilton is a show ambassador for House and will be on the Inspiration Stage every day at the RDS.
She will be speaking about creating beautiful interiors and giving away insider tips and tricks on colour, lighting and layout on Saturday, May 27, at 11.30am and again the following day at 12.30pm.
Hamilton will also be putting together a sample board live on stage with the help of the House audience as she talks about how to design your interior on Saturday at 3pm and then again the following day at 3.30pm.
She will also be speaking twice on the trade-only day (Friday, May 26), at 1pm and 4pm, about designing for the luxury market.
See johamilton.co.uk, andrewmartin.co.uk, ceadogan.ie, rugart.ie, therugcompany.com, christopherguy.com