In a bedroom designed by Frank Roop, an asymmetrical sofa stands out against a custom-built bookcase made of fine-grain Pau Ferro wood and leather shelves.

While working at legendary menswear retailer Louis in Boston, Frank Roop developed an appreciation for fine fabrics, an eye for detail and an ability to combine unusual colors or textures into a cohesive look. He took what he learned into the world of interior design and has since built a career creating custom-designed, couture-inspired rooms for his clients. In “The New Bespoke” ($65, Pointed Leaf Press), Roop outlines his design philosophy of mixing the old with the new, an approach that results in finely crafted, yet still functional, spaces. We spoke with the Boston-based designer to learn how to put together a standout room.

How does your background in menswear influence your interior design?
The store I worked for was really unusual. The owner had things that no one else had. He used to travel all over Italy and Europe, and would actually design his own suit models and work with famous tailors and go to wool mills. All of the things that came back into his store were unique to his store. So that was always beaten over my head, that having something special and unique is valuable.

How do you apply that principle to your work in homes?
It seems like nowadays more and more things look alike. People copy one another, or things are mass-produced. Everything is so recognizable that it’s hard to put together a space for someone that’s unique to them, unless you have the right ingredients. To give my clients something different, the principle I needed to stick to was custom-designing things for them or using found objects. That way, no matter how you spin things around, it’s going to be unique to the client.

The average homeowner might not think about having something custom-designed for his or her home. What’s worth the investment?
For an average homeowner on a budget, the sofa’s the huge thing [to get custom-designed]. The way I work is I design things to fit a space. It’s a game of inches, so I’m always messing with things like shortening a piece by 6 inches or making it an inch deeper. I think it’s important to have a sofa that fits the space really well. If it’s 6 inches too wide, then that’s an issue.

You’ve said that a room is a garment to be worn. What do you mean by that?
When I work with clients, I think about them and who they are and what their personality is like. I think of them sitting in the room, and they have to make sense there. I’ve met a lot of people who don’t make sense to their own houses; they don’t look comfortable in them, or the [rooms] don’t match … how they dress. So I try to establish a narrative about the client. I’ll think of a sentence about them or some sort of design aesthetic that makes sense to them and then I go backwards from there.

How could a person’s wardrobe help guide the design of their home?
The colors could, for sure. You start to see that people dress in warmer colors or cooler colors. But I don’t go in and find someone’s dress and say we’re going to make a sofa out of it. It’s more like broad brushstrokes. Are they someone who tends to be more modernist or classic; a jeans-and-cashmere-sweater person; or someone who likes to wear cool, hip, designer clothes? That gives me an idea of where to take the house.

You often use clothing-inspired fabrics for seating, like velvet and wool flannel. Why?
Those are classics. They tend to be good because they don’t go out of style so quickly. You can use them on large pieces of furniture and not feel like you have to reupholster every five years. They have longevity. And then you change them up. I’m a big fan of toss pillows; I play with those like you would with shirts and ties in menswear. I play with different colors and sheens, and fool around with things like that to come up with shots of color. And those kind of things are simple to change.

What do vintage pieces add to a room?
They’re so unique, and that’s what really gives character and style to a room. There’s nothing like something that has a little age to it and tells a story. The key to a really nice room is that you don’t want it looking too perfect. Then it looks too stuffy and too done. It needs be half collected and half a refined aesthetic, and then it feels more like a home, not a showroom.