WEST CAPE MAY — Gretchen Hoekenga’s super energy efficient house under construction here is like no other in the borough: it will have plants growing out of the roof and a pool that stays clean without chemicals.

The ultramodern looking house at 119 4th Ave. will be submitted for LEED (Leadership in Energy and Environmental Design) certification at the “gold” level.
LEED certification means an independent, third party has inspected the house and certified that it meets the highest green building and performance measures. LEED homes have lower energy and water bills, reduced greenhouse gas emissions and fewer problems with mold, mildew and other indoor toxins, according to U.S. Green Building Council.

Hoekenga, a landscape architect and college professor in Naples, Fla., has a Master’s Degree in Environmental Design.

The property started as a vacant lot filled with phragmites, she said. Hoekenga said this is the house she has always wanted to build.
The house is designed for an empty nester couple, she said.

The house has geothermal heating and cooling by using well water that is 55 degrees. The water is heated in winter and used for air conditioning in summer. Most lights in the house are fluorescent and all appliances are Energy Star certified.

The roof shingles are made of 85 percent recycled material. The green roof keeps heating and cooling costs lower, said Hoekenga.
First, a rubber membrane roof is installed and then flats of sedum plants are placed on top.

“You’ll see things growing out of my roof in a year or so,” said Hoekenga.

Kitchen cabinets are constructed of pressed sunflower seeds known as Dakota Board.
LEED certification is based on a point system, which awards higher numbers for each efficient, recycled or renewable item in the house.
Sustainable harvested items from within 500 miles of West Cape May provide more points, said Hoekenga.

The house does not have solar panels because it would not pay for itself, she said. The house features Kalwall, translucent wall panels that let in light but are very well insulated.

Architect for the project is Cecil Baker of Philadelphia with Cape May Carpentry handling the construction.
Hoekenga said she wanted a house that fit in with the vernacular of West Cape May, so the roofline reflects a 1920’s look with painted clapboard, a peaked roof and screened in porch without “trying to be something it’s not.”

“It is a modern house, it’s built in 2008,” said Hoekenga.

The house is about 3,100 square feet with two guest bedrooms with baths, a master suite, an office and a detached garage.
The lot is small, 50 by 150 feet, which gives the appearance the house occupies most of the property but it has two interior courtyards not visible from the street.

Plants, not chemicals, will filter the “natural” swimming pool. Floor tiles are made of bamboo.
Interior walls are Structurally Insulated Panels (SIPS) that are made in a factory.

Hoekenga said all greenery will be native plants. The property will use rainwater harvesting.

The minimum criteria for LEED certification is the house needs to be at least 35 percent more efficient than a standard house of the same size built in the same area, she said.
The house follows a “cradle to cradle” concept which means the materials used in the house last longer. The roof shingles have a 50-year life and can be recycled.

There have been a number of challenges for such an innovative project. Some of the SIPS panels did not fit which added four months to the project, said Hoekenga.

Once the kitchen counters, which will be made of concrete and appliances, are installed, the house will be completed, she said.
All told, the project has lasted two years.

On Dec. 17, Borough Commission introduced an ordinance amending floor area ratio regulations that will allow property owners or developers to add extra square footage to a house they are building if they include green features. Adding 25 LEED points would garner an extra 250 square feet, 20 points earns 200 extra square feet, 15 points adds 150, 10 points adds 100 and 5 points gets 50 extra feet.
Applicants would be required to submit a LEED scorecard for the credits they are seeking.