Kitchen is kitchen, living room is living room - and the twain shall never meet, right?

So say all practical housekeepers who want to keep the oil and smell of the cooking area in a contained space.

But not many young Singaporeans are subscribing to this school of thought. Instead, they have embraced open-concept kitchens in their homes, allowing their cooking areas to flow seamlessly to their living rooms.

The popularity of the open kitchen fits into the larger trend of open-plan layouts. Removing walls creates space, light and fluidity.

An open kitchen means a larger living room to entertain guests. It can also break down the barriers in a home and make it more sociable.

For example, parents can cook and watch over their children in the play area without a wall between them. Older kids can also do homework on the kitchen island.

In line with the growing popularity of open kitchens, the Housing and Development Board (HDB) announced on Sunday that all new Build-To-Order (BTO) projects will no longer have a wall between kitchen and living area.

One used to be able to opt for the kitchen partition wall as an additional feature, paying HDB an extra $370 to $710 - based on a BTO launch in August last year - for the service. But now, if a home owner wants a wall, he has to get his own contractor to build it.

Most new home owners, it seems, want open kitchens.

Such kitchens were first made available as an option in 2012 at the launch of Teck Ghee Parkview, a BTO project in Ang Mo Kio.

About 70 per cent of home buyers in that project chose not to have the kitchen partition wall.

Subsequently, open kitchens became available at BTO launches from September 2013, such as at the Park Grove @ Yishun project, as well as The Verandah @ Matilda and Waterway View projects in Punggol.

Of the 108 BTO projects launched for sale from September 2013 to November last year, 94 projects were offered the open-kitchen concept under the Optional Component Scheme.

These projects were in Bukit Batok, Hougang, Jurong West, Punggol, Sembawang, Sengkang, Toa Payoh, Woodlands and Yishun.

An open kitchen generally results in a bigger and brighter living area with good air circulation, but the trade-off is that one cannot do a lot of heavy cooking such as deep-frying.

This may not be a problem for more health-conscious people or those who eat out a lot, but if one is regularly whipping up heavy-duty meals in the home, a solution is to have movable partitions such as sliding doors and windows.

Another choice, says Mr Terence Neo, 35, design director at interior design firm Eightytwo, is to have air-purification devices to eliminate pungent food smells.

The studio, founded in 2012 and located in Siglap, has renovated at least five BTO flats that have open kitchens.

Mr Neo says: "There is some truth in the conventional mindset that smells will penetrate the living space as well as other areas of the home. But with technology in this day and age, this may not entirely be the case, with the help of kitchen hoods and air-purification devices."

Pristine, all-white open kitchen

You would not expect anyone to cook in here, let alone every day, but she does.

Almost everything in housewife Jade Hui's open-concept kitchen is white, from ceiling to floor: the walls, cabinets, countertop and kettle.

Ms Hui, 28, says: "It works for me because I hardly fry anything. I am Cantonese, so I mainly cook a lot of soup and stuff that is boiled, steamed or braised. Why do I need a partitioned kitchen to do that?"

A typical dinner consists of braised chicken with soya sauce, steamed egg, lotus root soup with pork ribs, with a side of boiled broccoli and carrots.

She cooks for herself, her husband, civil servant Gerald Thong, 30, and their 14-month-old daughter, Hailey.

They moved into their four-room HDB Build-To-Order flat in Teck Ghee Parkview in May last year, which came without a partition between the kitchen and living area.

The whole unit has an area of 93 sq m, with the living room and kitchen occupying about half of that space.

The renovation works for the whole apartment took about eight weeks to complete. Ms Hui estimates that the renovation cost for the kitchen, plus the cost of appliances, is between $12,000 and $15,000.

She says: "My parents' home has a partitioned kitchen. They have asked me if having an open kitchen means my furniture will smell. But so far, it does not."

For dishes that require simple frying, the family havean air-fryer and have used it to make fried chicken and fried fish. They also own a downdraft hood, which absorbs smells and fumes before they can reach the furniture in the living room.

Ms Hui says: "We do not regret having an open kitchen. In fact, it is something we have always dreamt of since wanting to own our own place."

Benson Ang

Space for big home gym

This health-conscious family of three are not fond of cooking or eating fried food. So when it came to deciding what sort of kitchen to have for their three-room HDB flat in Marine Parade, an open, no-frills kitchen was the obvious choice.

Papermaker Gordon Koh, 41, and his wife, Ms Angelyn Han, 41, a gymnast coordinator, moved into the 67 sq m flat in 2006. They have a daughter, Capucine, aged seven.

Mr Koh, who regularly participates in ultra-marathons and long-distance triathlon races, says: "Our home reflects our passion for sports and exercise."

Their utilitarian kitchen consists mainly of an oven, toaster, induction cooker, a few pots and pans and a 2m-long, 1m-wide island that functions as a food-preparation area and dining table.

Around it are four bar stools with no backs. "No backs are good," he says. "This promotes a better sitting posture."

There are also no cabinets in the kitchen, Instead, open shelves on the wall provide storage for pots and pans.

Having an open kitchen frees up space to dedicate to Mr Koh's passion - exercise and sports.

The living room is fashioned like a gym, with exercise equipment such as bicycle trainers and kettlebells. This allows him to train freely for demanding sporting events, such as the Ironman Austria event last year, where he swam 3.8km, cycled 180km and ran a full marathon.

Both his wife and daughter also work out in the living room.

His basic kitchen set-up is good enough to prepare their favourite food, which is simple. They usually have salads, wraps and sandwiches. Occasionally, they make soup, bake pasta and grill fish.

And if they need to cook anything more elaborate and there may be a smell, they will open the kitchen window and front door, which are aligned.

"A breeze will blow through the flat," Mr Koh says. "Any smell will disappear."

Benson Ang

Extended living room for entertaining

For this sociable couple who like to entertain, their kitchen is an extension of their living room.

A 2.4m-long wooden table, which can easily seat 12 people, extends from the living area to less than a metre away from their kitchen countertop, where food is prepared.

This extended "living room" now occupies 55 sq m of the 93 sq m flat.

The Singaporean couple moved into their four-room HDB Build-To-Order flat in Teck Ghee Parkview in August last year.

Mr Viknesh Barathan, 29, a bank executive, says: "Our family is very close and we have gatherings at our place at least once a month. I want a large living room with a long dining table so everyone can sit together and eat at the same time."

Neither of them are big on cooking. His wife, Ms Vijaya Krishnan, 29, a curatorial and logistics officer, says: "Both of us work full time. By the time we come home, it is already past 7pm."

When they do cook, they prepare simple fare such as pasta, noodles and stir-fry.

Benson Ang

No more cooking in a 'tunnel'

Open kitchens are usually favoured by people who do not cook much.

But junior sous chef Khalit Sulaiman, 32, has decided on one for his four-room HDB flat in Woodlands, although he regularly whips up dishes such as beef rendang, spaghetti aglio olio, and turmeric and coconut chicken.

His wife Siti Norhaliz Salleh, 33, also enjoys cooking Asian fare such as curry, stir-fried beehoon and sambal prawns.

The couple decided to open up their kitchen because they wanted a more spacious and fluid home. Without an obstructing wall, it is also easier to keep an eye on their 18-month-old son while they are in the kitchen.

Besides, the couple have only two precious hours of time together a day. Mr Khalit juggles two jobs - first as a junior sous chef at Lucky Cuisine bistro at the Gain City Megastore in Sungei Kadut from 9am to 7pm, followed by a night job at the Bishan MRT depot from 11pm to 4am.

Not having a wall between kitchen and living room means that the conversation can flow easily between them.

Before the couple moved in, the kitchen could be accessed only through an archway to the left of the flat's main entrance.

They engaged an interior design firm, TS Dezign, to remove that wall separating the kitchen from the living room area.

The dining table is now just next to the countertop, making it easy for the person in the kitchen to pass the food directly to those at the table.

The renovation works for the kitchen set them back by about $8,000. But it was worth it, Mr Khalit says, given how the kitchen is about 2m wide.

It now feels less cramped because it is not hemmed in by walls.

"I don't want to feel like I am cooking inside a tunnel," he says.

Ventilation is not a problem. When they cook, they open the kitchen windows, switch on the ventilation hood, place a table fan on the kitchen counter and switch on the ceiling fan in the living room.

The only drawback of having an open kitchen, he says, is that the place "needs to be squeaky clean".

"If not, your guests will see it."

Toh Wen Li