It takes natural resources to make the materials that we use to build a home, energy to obtain the materials to build a home, and it takes energy to live in and operate our home. Another word for energy is money.
One material, Structural Insulating Panels (SIPs), helps enormously on every front imaginable including energy efficiency, resource management, embodied energy (EE), reduced waste, recycling, improved quality, reduced construction time, and affordability.
SIPs are a key energy-conserving strategy. An 1800 square foot Right Home in a 6,500 DDH climate will save about 34,000,000 BTUs in annual heating energy which converts to 270 gallons of fossil fuel compared to a HUD code house same design. At $2.80/100,000 BTUs that is a $950 annual savings.
While the foam for the SIP uses petroleum products both as a resource and as energy to make the rigid foam insulation, it is a substantially better use of this resource. The gas that we put in our cars is used just once for about 25 miles leaving behind polluting greenhouse gases and more. The Expanded Polystyrene (EPS) Rigid Foam Insulation of a SIP will save energy for as long as the home exists. And with these homes, life is measured in many, many generations.
It takes almost 4 million BTUs to fabricate and install wall and roof SIPs for one of our Right Homes. This investment immediately saves 34 million BTUs in energy costs, that is a huge return on investment. And year after year for generations those SIPs save the 34 million BTUs.
Let’s address the Oriented Strand Board (OSB) that is used as the outer layers of the SIP. It is made from a farmed and harvested crop wood. Though it is harvested every 10 or 12 years, crop wood is just like corn - planted and harvested and replanted. This is ultimate resource management – replenishing the resource.
Every resource we use depletes our natural resources. It is estimated that in 1985 the human population began to consume more resources than earth could replace naturally. To put this in our local homebuilding perspective; in 1970, there were 44,800,000 single family homes (sfh) and 40 years later there were 77,701,000 sfh a 73.4% increase. The average building size grew by 1,000 sf per home. The average family size went down from 3.14 to 2.57 - larger homes for smaller families – this makes no sense.
We at Right Home Company have chosen to go back to some of those turn of the century designs which were smaller and more appropriate to today’s family size. And we went to a well understood simple energy-saving technology to enclose the design resulting in what we feel is a great solution to the many issues.
And while wood is recyclable and renewable, system built components offer major environmental savings, fewer trees to harvest and replant, less lumber to process and more efficient recycling in the plant, all of which require energy to perform – less lumber is less energy.
There is about 2,150 sf wall area in a 2000 sf 2 story home. This requires about 17,000 bf of 2x6 wall framing and sheathing material. The lumber in the same 2,150 sf of wall using SIPs for top and bottom plates, splines, window and door bucks, corners, and both layers of OSB is less than 3,500 bf – one-fifth of the lumber of a 2x6 conventional wall. And the 2x6 site-built wall will be some 1200 pieces of lumber and a gazillion nails, most of which will be improperly placed.
SIPs belong to the System Built approach to construction meaning they are pre-fabricated in a plant or factory. This results in many benefits including a controlled environment to make the panel, better and safer working conditions for the carpenters, better use of materials, less waste and the waste is recycled because it is better managed. This simply translates to;
- Faster construction meaning fewer labor hours on site to install the SIPs which means fewer carpenters drive fewer miles saving fuel and the environment
- Substantial reduction of site construction material waste which is less impact on landfills. This easily equates to the cost and impact of 35 yd dumpsters
- EPS foam uses steam to expand the styrene pellets into large billets and has no toxic outgassing, is infinitely recyclable and reusable into other products such as ‘Styrofoam’ cups, insulation for coolers, packaging, soil enhancement, reconstituted into other building products such as decks and railing, furniture, and so much more.
- OSB uses non-toxic resins and wax binders, has a very low VOC rating, and has no toxic outgassing, is reground to make particle board, or compressed into wood pellets fueling heating devices, and much more
- EPS SIPs are made in sizes up to 8' x 24' which offers countless manufacturing and construction advantages. Working with large sheets allows a better use of materials in the ‘pre-cutting’ phase of fabrication. Larger individual pieces on the job site save installation time while reducing the number of ‘connections.’
- SIPs are far more accurate than site-built wall and roof framing which improves the workmanship of many other trades including straighter walls to hang kitchen cabinets and OSB behind the sheetrock, and flatter roofs for shingles.
All these high-performance strategies matter.
- There are utility energy and costs savings
- Increased durability for longer life
- Improved indoor living environment for better health
SIPs promote lower total costs.
- Less cost to build
- Less cost to own
- Major cost savings to the environment through highly reduced impacts on landfills
- Reduced energy generation (furnaces and AC units),
- A very sensible conservation approach to home energy demands,
- Reduced delivery and construction travel time,
- Fewer mistakes on site as SIPs are cut to size
- More effective communications among the construction crew.
- Equally important is that this building system encourages environmental awareness and stewardship of our increasingly scarce resources; we have a responsibility to our future generations.