TRACY HANES PHOTO

Craig Marshall uses a push mower to trim the grass driveway, which sits on honeycomb-shaped plastic cells, at Marshall Homes' LEED Gold house in Oshawa as Golden Retriever Dixie looks on.

The green, green grass of home

You won't ever have to pave or seal it, but you will have to water this driveway regularly.

Marshall Homes' LEED (Leadership in Energy and Environmental Design) model home in Oshawa marks one of the first residential uses of a grass driveway in Canada. Underneath the seemingly ordinary patch of lawn are a series of interlocking, hectagonal-shaped moulded plastic cells in which grass has been planted. The cells protect the roots from being crushed by the weight of a vehicle and allow water to flow through into the ground. The system has a load-bearing capacity of 100 tons per square metre.

The grass parking area is designed to reduce groundwater runoff, thus reducing the impact on nearby lakes and streams, in line with LEED criteria.

The Golpa system, invented in Germany using recycled plastic, costs about $10 per square foot, or five times as much as a paved asphalt driveway, says Craig Marshall, president of Marshall Homes. However, it doesn't have to be resealed or repaved, is more aesthetically pleasing and easier on the environment than pavement. It takes the same type of maintenance that a lawn requires.

While whole parking lots in England are made of grass, Marshall says the Brits don't have to cope with Canadian winter – and how the driveway will survive snow shovelling remains to be seen.

"Everyone who sees it wonders about that, but we're going to find out if it's feasible before we start offering it to home buyers," says Marshall. "It's a trial project. We'll be posting a diary and photos on our website."

Marshall has planted his LEED house driveway with hardy Kentucky bluegrass but says there is no reason someone couldn't use another form of grass or even ground cover.

"Grass is pretty resilient, though," he says. "You can play soccer on it, you can golf on it, you can park cars on it."

While the two-storey house on Copperfield Dr. is his first LEED house – and one of the first LEED Gold houses in Canada – Marshall has been a leader in energy-efficient construction, as an R2000 and Energy Star builder and the first in Ontario to offer solar-powered hot water heating and geothermal heating in subdivision homes.

While the grass driveway is certainly a conversation piece, Marshall is more excited about some of the home's more practical energy-saving and environmentally friendly features.

One of them is the Brac grey water recycling system, housed in a large plastic tank in the basement, about the size of a hot water heater. When residents of the house take a shower or bath, the drained water will be saved in the storage tank, which filters it. It will then be used to flush toilets in the house.

"Typically, 35 per cent of a house's water use is for showers and 30 per cent for flushing," says Marshall, and by recycling and filtering greywater from showering and bathing, homeowners can save about a third of their household water consumption. It also saves Durham Region money: about half the region's energy budget is spent on water delivery, which requires electricity to power pumps which draw it from Lake Ontario to the city's neighbourhoods.

Marshall has also given a family of seven who lives in one of his houses the Brac system to test its "real life" use before offering it as an option to purchasers (it costs less than $2,000). The system does require that its filter be cleaned and a chlorline tablet added each month.

Marshall notes that the LEED point system still has some inconsistencies – the greywater recycling system receives only one point, while a drainwater heat recovery unit, which saves 15 to 20 per cent of the heat from water going down the drain – receives six points.

He is also enthusiastic about Boomerang Paint featured in the LEED house, which is now a standard in all Marshall houses. The paint is made from recycled latex paint, which otherwise would have gone to landfill and as it was cured in its first life, there is virtually no off-gassing. As well, Boomerang paint cans are made from old ones which were melted down and reformed.

Other features of the LEED house, which is also built to Energy Star standard, include: super-insulated walls and basement; low E argon windows designed for far north climate; heat recovery ventilator; programmable thermostat; ECM furnace motor which uses 25 per cent less electricity; compact fluorescent light bulbs; low-flow shower heads and taps; 4.5 litre (versus 6 litre) toilet; timed bathoom ventilator fan; extra windows to allow plenty of natural light; recycled plastic PEX plumbing; fireplace spark igniter instead of pilot light.

An open house of the LEED Gold house at 1025 Copperfield Dr. is scheduled for today, from 11 a.m. to 3 p.m. Representatives on hand will explain the grass driveway and the LEED home.

Another open house will be scheduled for September. If interested in attending the fall open house, visit www.marshallhomes.ca to register.