How to spot a marijuana 'grow-op'
By Fiona Wagner • Bankrate.com

When east Vancouver residents Chad Skelton and his wife, Janice, were awakened at 3 o'clock one July morning by a loud bang and people shouting, they might have expected a car backfiring or teenagers playing with fireworks. Instead, upon looking out their back window, they were surprised to see a cop with his gun drawn. It was a drug bust. The neighbouring house was raided and 750 marijuana plants seized without incident. Talk about your bad neighbours.

"The house was pretty rundown and a bit shady, but we had no idea it was a 'grow-op,'" says Skelton. "Because they had so many visitors, we often jokingly referred to it as 'the crack house.' Guess we had the drug wrong."

While Skelton's backyard neighbours fit the stereotypical profile of an illegal drug house -- ill-kept, deteriorating roof, complete with nesting pigeons, and a garbage-strewn backyard -- more and more grow-ops are found in $500,000 suburban homes, complete with manicured lawns and rose gardens.

There's not one typical house or neighbourhood where criminals set up shop. Grow-ops are often housed in rentals (to pass the onus of property damage on to the owners) and sophisticated operations have been busted in apartment buildings. What's worse, unsuspecting homeowners are buying these tainted abodes.

But there are several signs that the house next door might be cultivating the wrong kind of grass or that the house of your dreams might in fact be a "handyman's special."

A growing problem
It's hard to peg the number of grow houses in Canada. Some estimates put the number at 50,000, though it could be much higher. The grow-op problem is particularly serious in British Columbia, Ontario and Quebec, with almost 1.9 million plants seized last year from those three provinces alone. With an estimated retail value of $1,000 per plant, it's clear to see that growing grass is big business.

But with big business comes a high price, and it's property owners and neighbours who have to pay.

The risk of grow-ops
Regardless of your opinion on smoking pot, the risks of grow houses are very real. Grow-ops are electricity hogs, requiring three to 10 times the power demands of an average house (blame the 1,000-watt high-intensity growing lights and heavy duty cooling and ventilation systems.) To avoid detection, growers bore holes through the house's concrete foundation and tap into the main power cable, bypassing the hydro meter. There are no circuits or fuses to protect the incoming load of stolen power, creating a dangerous electrical hazard and fire risk.

Grow-ops elevate the temperature and humidity levels in the home to a balmy 25 degrees -- ideal conditions for toxic mould growth. This mould can coats the walls and ceilings of a home, or the infestation may be more sinister, eating the walls from the inside out.

"You can get mould growth throughout the structure and into the attic," says Frank Haverkate, president of Haverkate & Associates, a Toronto-based environmental testing company. "It usually hides. In a lot of these cases there's a lot of contamination behind the drywall."

The structural damage gets worse. Holes punched through walls and ceilings accommodate elaborate exhaust systems and ducts that vent excess moisture and odours. Operators often disconnect furnace and hot water tank flues to help "feed" the plants, poisoning the air with excess combustion gases. 

While "crop sitters" are responsible for the plants' day-to-day upkeep, organized crime usually backs the operation. "Whenever organized crime is involved, they want to make a profit. They want to make money and they'll use whatever means it takes to get there," says Denis Pelletier, Marijuana Grow Operations Coordinator for the RCMP.

It's no surprise, then, that neighbourhoods with grow-ops are more susceptible to gang violence, home invasions and even homicide. To protect their investments, grow-op owners often set-up booby traps such as electrified doorknobs or mechanisms that fire shotgun shells indiscriminately at uninvited guests, including police personnel or the neighbourhood paperboy.

Buying a grow-op?
Living close to a grow-op isn't the only risk. Canadians are buying these homes without knowing their sordid past. While some police services post lists of confirmed grow-op addresses, unscrupulous owners can often cover up the ravages of grow-ops with plaster and a good paint job.

"We do a lot of marijuana grow-op testing right now and unfortunately, many of the calls are people moving in and the neighbours say, 'Hi, nice to meet you. We're surprised you bought a grow-op'," says Haverkate. "In some cases they get lucky and there's no damage. In others, to fix a mould issue from a grow-op, you're looking at $10,000 to $20,000." Or more.

Grow-ops are red flags for insurance and mortgage companies, which may suspend coverage until remedial action has been taken. To avoid being hit with a huge clean-up bill, Haverkate says there are some visual cues that a home may have once been a grow-op. Concrete patchwork around the electrical panel in the basement suggests a hydro bypass, staple marks around the windows could be from tight window coverings and hook marks in the ceiling might have been left from suspended growing lights.

"Those are just the initial cues," says Haverkate. "You really have to do an environmental assessment" and test the air quality for mould spores and other contaminants.

How to spot one in your neighbourhood
Even if you're not shopping around for a home, it's important to keep an eye on your neighbourhood. While grow-ops can be hard to spot, the RCMP provides several clues that a home may be concealing a marijuana grow-op:

How to spot one in your neighbourhood:

• All windows are covered, often with dark plastic or newspaper. • Condensation forms on windows due to high humidity levels inside. • Residents may only be in the home occasionally and for short periods of time. • Unusual visitor behaviour -- no visitors or frequent visitors for short periods. • People access the home only through the garage. • Strange skunk-like odours. • Unusual garbage -- little or no garbage or unusual items such as pots, soil and wiring. • Sounds of electrical humming or fans. • Unusual wiring on the outside or signs the hydro meter has been tampered with. • Little snow (or steam) on the roof in winter. • "Beware of dog" or "Guard dog on duty" signs and excessive security. • Localized power surges or brown-outs. • Bright interior lights left on all day and night.

If you suspect there is a grow-op in your neighbourhood, call your local police or Crime Stoppers unit. "Don't try to investigate yourself. Don't go on the property and don't take any action that can get you injured or killed," says Pelletier.

Fiona Wagner is a freelance writer in Georgetown, Ont.