Building the green way: Getting the r-value right

Energy efficiency and environmentally friendly building technology begin with construction methods that are mindful of the environment and the climate.  

 

Davenport Development, along with its sister company ICF Builders Cayman Ltd, employs a construction system known as insulated concrete forms or ICF. The forms are very common in the United States but are also gaining popularity in the Caribbean.  

The system uses insulated concrete forms that result in extremely strong walls and floors, ideally suited to Cayman’s weather conditions. The foam blocks are connected through webs and once the blocks are in place, reinforced by steel, concrete is poured into each foam block. The result is a reinforced concrete wall, encased in five-inch thick Styrofoam.  

“The forms are manufactured here on island,” says Paul Pearson, director at Davenport Development. “Flowers Foam produces it here according to a specifications by Fox Blocks, one of North America’s leading ICF manufacturers.” 

ICF has essentially replaced traditional wall insulation, because it makes ICF building both energy efficient and hurricane resistant. The building technique has a high insulation rating, which translates directly into lower energy use and energy cost savings. “They give tremendous r-value ratings to a house,” says Pearson. “A traditional cinder block has an r-rating of six and these have an r-rating of 32.” 

The r-value measures the resistance to the flow of heat through a given thickness of material with higher numbers indicating better insulating properties and the potential to save energy. 

According to Pearson, Davenport’s developments Valencia Heights and Lantern Point report electricity bills of between $220 and $250 a month for about 1-200-square-foot compared to traditional 1,200-square-foot foot houses, which would be in the region of $600 to $700. 

ICF insulation itself is made from recycled materials and considered a green product. “The inside of the blocks is made from recycled foam and recycled plastic.” 

In addition to being environmentally friendly and durable, it is also a cost-effective alternative to traditional construction methods. 

“It is a great thing to work with and the fact that we can buy it locally on Island from Flowers, who are such a great manufacturer, that works really well,” says Pearson. 

In terms of speed, ICF is a much faster construction method than regular CMU block. While the initial outlay for the blocks is more expensive, savings in time and labour balance the costs, Pearson says. 

Davenport Developments also thoroughly insulates all of the attics and roof spaces. The covering that is put on the roof top terraces at San Sebastian, repels UV rays and heat. “So we do everything we can to keep the inside of the house cool, which is very important in this region and helps saving energy and money,” says Pearson. 

He sees a definite change in home buyer attitudes. When Davenport began using ICF blocks as one of the first construction firms on Island six years ago, home owners were more interested in the strength of the building. “After Hurricane Ivan it was all about the Hurricane proof and strength of the construction,” he says. “Now it is all about the r-ratings and energy efficiency.” 

The high energy cost may be a stronger incentive than simply environmental awareness, but people are also becoming more aware, he says. 

“For example people want to see us use LED lighting in the yards and in the landscaping.” 

Windows   

The energy efficiency of a building is also dependent on the type of windows used. For its San Sebastian development, Davenport has switched from its previous PGT windows to a new brand.  

“It started out as an aesthetic issue,” Person explains. Given the arched shape of the windows at San Sebastian, he never saw any shutters that he liked. So Pearson preferred a window that does not require any shutters and began sourcing European technology windows, based on Italian design and German components manufactured in Miami-Dade. 

More expensive than the previous brand, which already had good environmental ratings, the new windows are a real good quality product, which does not let in 89 per cent of the UV light and heat, according to Pearson.  

“That was an interesting benefit,” he says about the improvement in ratings and product quality. 

Pool  

The San Sebastian development also saw the use of a saltwater pool that does not need any chemicals. “Again that was more expensive, but it saves money in the long run for homeowners,” Pearson says. 

The saltwater technology used for the award winning pool was very much demanded by the homeowners. Avoiding chlorine and other chemicals was very important for a family pool and very much an awareness issue on the part of homeowners, he says.  

Limitations  

Cayman remains still limited in the green technology and products that can be used here, especially compared to the United States, where a lot more products from reclaimed materials are available.  

“In the US you can use sheetrock made from recycled materials, but all these things are very expensive here because of transport costs,” says Pearson. “We do as much as we can and make sure that the insulation we use is recycled.”  

As prices are coming down in the US, Pearson hopes Davenport will be able to reflect that and introduce even more green materials. 

RRAting

The award winning salt water pool at San Sebastian uses no chlorine or chemicals.

NO COMMENTS