Winter is the best time of the year to tackle your home's odour problems. Tightly shuttered doors and windows may retain heat effectively, but the lack of fresh air makes household odours more noticeable this time of the year.

While homeowners go to great lengths to make their homes picture perfect for guests every winter, any lingering odours in the house might mean they take away some less-than-pleasant memories of their stay.

But most people are habituated to their home's unique scent and often don't realize there is a problem.

"It's a blind spot for most people," says Dr. Michael Masson, professor of psychology at the University of Victoria. "A homeowner will find it difficult to detect any smell difference because they are habituated to it."

A person who smokes, for example, likely can't smell the tobacco smoke that has permeated carpets, draperies and other surfaces of a house. The same can be said of pet owners.

While friends will be used to a person's unique scent and identify that smell to the individual, real estate agents would be generally be the first group of people who would take it upon themselves to inform a client that they have modify or eliminate less-pleasant smells around a house before it can sell.

"In my experience, the absence of smell is the best smell," says Mark McDougall, an agent with Royal LePage Coast Capital. "It doesn't offend."

In preparing for an open house, he recommends clients have their house cleaned, especially a hot-water extraction (sometimes known as steam cleaning) of the home's wall-to-wall carpets. While some people will just put out bouquets of potpourri or bake bread prior to guests arriving, McDougall says these strategies can backfire and make visitors think homeowners are trying to mask a problem. "To me, they reek of desperation."

Cleaning experts agree.

"Whenever we get a call to get rid of a bad odour we first have to uncover the cause before we can eliminate it," says Alan Bowles, owner of the local Servicemaster franchise. "That's a more effective strategy than applying a deodorizer to mask the problem temporarily just to have it return eventually."

Use of deodorizers and other scented products can sometimes bring on problems of their own. Cleaning products and perfumes can cause allergic reactions to people who are sensitive to products that emit volatile organic compounds. Symptoms range from a headaches to nausea.

"I once walked into a house and had to turn around and walk back out because the perfumed smell was so overpowering," recalls McDougall.

The cleaning industry has responded to consumers' concerns with products with little or no fragrance. But the demand among the majority of population who are not hyper-sensitive is low.

"People generally want their house to smell fresh after a cleaning," says Scott Tanner, owner of the local Merry Maids franchise.

"If they don't smell something, they think it hasn't been cleaned -- so we use a green product that leaves a light scent. We use unscented products when a client asks for it."

While professionals can get a house thoroughly cleaned, a homeowner can tackle a home's most likely sources of odours:

Carpets

The major item to keep cleaned in a home is the wall-to-wall carpeting, say the experts.

"The carpet is like a sink," says Bowles, who has over 30 years of experience in the field. "Typically, everything falls into it."

He says that regular vacuuming will extract 80 per cent of the particulates. A sprinkling of baking soda before vacuuming will take care of some of the smells. Carpets should be cleaned by hot water extraction every 12 to 18 months, he says.

Cigarette smoke

The smoke permeates into the carpeting, drapes and can permeate latex paint and lodge in porous walls such as plaster. It will typically be infused into the clothing of smokers. Frequent hot water extraction of carpet and drapes helps. People have to repaint walls and clean the heating system of a house to eliminate the odour.

Cooking

Apart from smoking, cooking is the most common source of a home's odour. Some people swear by lining the counter with newspapers when frying or simmering a pot of water with white vinegar on the stove. It is a good idea to close doors (if any) of the kitchen when cooking to prevent smells from entering other parts of house. To create a current to clear out smells -- and not just dilute the air -- a cook needs to open a window or door on opposite ends of a kitchen.

Dogs

People love their dogs but not always their smell. The "dog smell" most people notice is caused by their skin oils going rancid. Keep odours at bay by regular brushing, combing and bathing. Homeowners should vacuum frequently and consider reducing the amount of carpeting around a house. Thoroughly clean areas where dogs eat, sleep and play. Some breeds without undercoats, such as greyhounds, seem less prone to doggy smells.

parrais@timescolonist.com