Sought-after architect and interior designer Mr Ben Pentreath on the elements that enrich English style.

The English, once famed for their eccentricity and boldness, have apparently become a bit dull. A bit… Farrow & Ball. “We’ve become quite frightened of colour, quite timid with pattern in decoration in the past 15 years,” says Mr Ben Pentreath, a 44-year-old architect, interior designer and founder of Pentreath & Hall, a destination interiors store based in London. “That beige phase in the 1990s has turned into a more tasteful version now: pale greys… It’s great, but it’s not my idea of English country-house style.”

Mr Pentreath, who studied his primary craft at the Prince of Wales’ Institute of Architecture, has a different agenda for his interior design business: one rich in colour and pattern, thrown together and often at odds with one another in a resplendently carefree manner. “For me, an English house has layers,” he says. “Of history and stuff. Nothing goes together. Everything is completely random, but it’s the randomness that makes it.”

His London home, which he shares with his equally creative husband Mr Charlie McCormick, acts as a visual mood board of his aesthetic values. Brightly coloured cushions by Mr Josef Frank and Mr Luke Hall (“He’s one of my ones to watch – he is doing a pop-up in the shop in April”) are scattered vivaciously on the sofas. Floral curtains by famous mid-century French interior decorator Ms Madeleine Castaing frame the full-width windows that look out over Queen’s Square in Bloomsbury. The kitchen is an unusual combination of what Mr Pentreath describes as “cow-pat green” walls and pink wooden floorboards (“I love it. It’s cool!”). Grass-cloth wallpaper adorns the walls of his living room (save for one wall, which is filled entirely with framed segments of an enormous map, copies of which he sells in his London store). “I use seagrass a lot. It just has a warmth and a texture, and looks great in the evening,” he explains.

Here we take a tour of Mr Pentreath’s London apartment to discuss his sources, extract some sage decorating advice and discover the design inspirations that have made his house a home.

It’s a distinct, slightly chaotic vibe, utterly charming and unmistakably English, but it works, so much so that Mr Pentreath’s eye for design is now in great demand. Business is ticking along nicely with an expanding team, growing waiting list and a soon-to-be-published glossy coffee-table book, English Houses. The book, due out in September, features inspirational interiors from 10 of Mr Pentreath’s favourite English homes – along with the Bloomsbury flat that we’re standing in and his country home in Dorset. So what makes an English house so… English? “It would be a complete sin if it looked like it had been decorated,” he says “It’s high and low. My favourite image is the one of the Queen at Balmoral sat in the grandest room imaginable with an electric bar heater in the fireplace. I love that. You can’t make that up.”

What projects do you have in the pipeline?

Right now, I’m working on a large urban design scheme in southeast Ayrshire for the Prince’s Trust. Prince Charles helped to save a stately home called Dumfries House, which was due to be split up and sold off along with its contents. He stepped in with a personal donation at the last minute to keep it going. There’s a development happening on the edge of the estate, which I have helped design, with the aim of improving the quality of housing in the area. I love that side of my work, the master-planning, as you are effectively designing whole towns and composing street scenes.

You have become well known for your classical and traditionalist architecture. What type of design is inspiring you right now?

I do all sorts, actually, but I’m probably best known for that aesthetic. I’m working on a contemporary approach in Chichester at the moment, so I’m not too style-bound. I’m quite inspired by Danish or Scandinavian architecture from the 1930s or 1950s, where everything was stripped back to focus more on materials and spaces, and there was no clutter. And that’s very beautiful.

What is your overall aim when you design and decorate a building?

Basically, I’m trying to make buildings that feel as if they belong. That covers a whole range of styles or approaches.

You have an interiors store below your offices. Is it unusual for an architect to have a shop?

Yes, it’s very weird and came about simply because we needed more office space in our Lamb’s Conduit Street office, so I decided to take the two spaces next door, but due to certain laws it had to remain, in part, a shop. I had planned to rent out the store space, but after a trip to New York and a visit to a fabulous shop in the East Village called John Derian, I decided that this was the sort of thing I should be doing, something energetic and expressive of my values and my business. I teamed up with my friend Bridie Hall, a decorative artist and painter, and we opened our doors. We were so surprised at how well it did.

Does the switch to interior design from architecture have its challenges?

Decoration is tough because it’s just a matter of opinion. There’s no right or wrong involved. It’s very personal. With architecture, you take somebody’s brief and you can often morph their ideas and find an architectural language that’s going to work for that project, that site, that person. But on the decoration side, if someone says they don’t like blue, you can’t argue with that. I’m increasingly finding that I have to have almost an overbearing and arrogant confidence in my taste and ideas. Which is hard because you are not the one who’s going to live there.

How would you describe your taste?

Our house in Dorset is much more traditional than this one. A bit more old lady: pink walls and chintz. That’s what the house down there needs. I believe that, to a certain extent, you have to listen to the building. This flat could be decorated in a very traditional way, but we wanted a contrast. Here it’s about creating a big mix, which I guess is part of the feel I go for. A lot of the things in the room are old – Georgian furniture, very traditionally styled sofas and chairs – but they’re mixed with contemporary pieces, such as the 1960s Danish dining table and the Fornasetti Palladiana chest of drawers, which were a big splurge. Everything else is cheap as chips.

Tell us about the map in your living room.

It’s a reprint of a map of London that was created around 1750 by a famous map-maker called John Rocque. I knew about its existence for years and tried multiple times to get a copy of it, but it was out of print. I’d follow up every six months with the company in Kent that owned it, and I became quite annoying. Four years went by of doing this and eventually I got an email from the owner offering me his copy. It was originally printed on copper plates – 24 of them. He sent it to me, I framed it and it was in my office for around four years until we moved into this flat. I then realised it fitted exactly on this wall, like it was meant to be. It’s quite weird. Anyway, we worked out a method of scanning this copy of the map and we now sell them in the shop, unframed, in a big book.

Create a blank canvas

“If you’re not sure what to do before you move in, paint the whole place white and live in the space for a while before you choose the right wall colour or paper, particularly if you are dabbling with stronger colours and fabrics.”

Get to grips with online auctions

“I buy everything on eBay. It’s the best source for every single style of furniture in the world. You need to be quite specific when you search. I bought a gorgeous dresser for a client on a really fancy job we are doing and we needed something very particular. I tried all the usual dealers and then found it on eBay. We are refinishing it, but it’s a really nice piece of furniture we couldn’t have found anywhere else.”

Rent wisely

“If you rent, the key thing is getting a long lease and a benign landlord. The lease here is seven years, but will be renewable. So I always know that we’ve got the time and the room to do what we want. I’m not a lawyer, I’m an architect – I couldn’t possibly afford to buy in Bloomsbury. But I love being able to walk to work. It’s a dream. These longer-term arrangements mean I can make my own mark.”

Use pattern on changeable pieces

“In a room like my [living room], there’s actually not that much pattern. If I changed the curtains, changed the lampshade and took out the cushions, you’d be left with a much calmer vibe. That’s the trick with pattern. You might get bored of it, so make sure it’s something you can change later on.”

Big is often better

“I’m really into having big pieces of furniture in a room, such as the ottomans we make, one of which forms the centrepiece of our living room. Don’t be afraid of choosing large items because they can really animate a space.”