“I’m not drinking until April,” boasts Riette as she sips her hot water and lemon. I feel a little guilty as I knock back a double espresso.

We’re in consultant HTA’s office to christen the latest addition to its cafeteria – a stylish new coffee maker. “Some people have been rude about our coffee,” snaps Lucy, casting a shifty glance towards a far corner of the open-plan office, “but now they can’t complain.” She wanders off to the kitchen.

I enquire about their coffee preferences. Steve favours Italian brand Illy, but concedes it may be too predictable a choice for such a chic office. “There is a place nearby where you can mix your own coffees, if you’re fussy,” he says. “Which I’m not,” he adds, chuckling.

Colin recalls a coffee shop in Camden. “They specialise in North African brands,” he says. Riette joins in, and a lengthy debate about regional coffees follows. The novelty of their new toy has not yet worn off.

“My new year’s resolution was to stop eating chocolate,” Lucy says, returning with a plate of scrumptious-looking biscuits. “But I forgot, rolled in at 4am on new year’s day and ate a whole box!” She grabs a chocolate-chip cookie.

“I forgot to make a resolution this year,” mumbles Colin through a mouthful of ginger biscuit. “Last year I didn’t drink for 10 days out of each month.” He looks smug.

“It sounds like you have a drink problem,” teases Steve.

I mention recent reports that we are a nation of binge-drinking alcoholics. “And we’re proud of it,” Lucy jokes.

South African Riette is more serious. “When I first came here I wondered how you could go out every night just to drink,” she recalls. “Now I do it too.”

“There isn’t much pub culture in Australia either,” says Steve. “People just drink in parks.”

They all laugh. I should have taken them down the pub.

Now the caffeine has kicked in, the conversation takes a serious turn. “The sustainability agenda is driving design quality,” says Colin.

“You have to sell a new lifestyle to the public,” adds Riette.

“The Swedes have such drive,” Steve interrupts, referring to a trip he made with Colin to the Swedish eco-city Malmö. “The whole refuse system is a series of suction tubes under the ground,” he explains. Colin takes over: “We asked the guide what happens if kids throw, say, matches down it.”

Apparently the guide was baffled at such a suggestion. “Here, kids would be throwing their little brothers in there,” says Lucy. They all laugh.

The conversation has taken a bizarre turn. Post-festive blues or something in the Illy beans, I wonder as I exit the building …

Chosen venue: Cafeteria, HTA headquarters, Kentish Town Road, north London 

Ambience: Understated kitchen area dividing the open-plan office

Topics: coffee and alcohol 

Drinks drunk: Three lattes, one double espresso, one hot water with a slice of lemon and four biscuits

Steve Newman director of building design
Colin Ainger project director
Riette Oosthuizen head of planning Lucy Whitehead marketingco-ordinator
Nargess Shahmanesh-Banks Building