FAQs

Q?Where could I build an earth sheltered home?
A.

These homes can be built on flat, sloping or steep sites. The base floor level can be as far as 22 feet below the finish grade. The shell is engineered for all soil requirements. Our energy efficient structures — utilizing solar energy and natural forces — have been built from Washington State to New York, from the hot Arizona desert to the extreme cold of Minnesota and Michigan.

Q?Will my earth-sheltered home blend-in with surrounding conventional homes?
A.

These homes can be built in all types of neighborhoods — in the city, in the country, or in the suburbs. The front of the home can be customized to suit the neighborhood’s appearance and the type of site. Check out “Finished Homes” for pictures of completed homes. Any style, South Western to Victorian to Modern is possible.

Q?What are my options?
A.

The structural forming system is designed to be both modular and versatile. Standard sizes include: 24′ diameter – a single floor, 32′ diameter – a main floor with a central loft area, 40′ diameter – a main floor with a full 2nd floor, and 50′ diameter – two full floors, with a 3rd level available by way of optional cupola

Each of these sizes can be built as a dome, an open-ended dome, or a double open-end barrel. Each size can be elongated to your desired length in standard 6ft increments. The modules of the same or different size can be connected directly side-by-side, perpendicular, or at an angle nearly perpendicular. Cupolas and atriums can be used to provide additional natural light, views, enhanced natural air circulation, and private patios. Please see “Models” for square footage and prices.

Q?Why should I use your kit?
A.

Unlimited technical support from factory
Availability of free advice from our extensive 30 plus years of experience
Proven design already built in many different locales and climatic conditions
Inexpensive method of forming structures ranging from pure domes to oblong shapes
At least one on the-job-site inspection regardless of location in the continental United States
Only system capable of merging dome shapes and barrel shapes with the option of open and closed ends on the same structure

Q?What is included in the kit?
A.

The kit includes the materials to form the structural shell. (Main support beams, compression ring, foot plates for main beams, outer floor supports, forming panels, reinforcing rod for shell above foundation, tie wire, rebar pockets, and all nuts and bolts required for assembly.) The kit does not include wood, concrete, interior materials, waterproofing and insulation, floor plans, engineering or shipping.

On-site inspection of the kit assembly by PBSI personnel is included in the kit price — regardless of the site within the continental United States.

Q?Won’t it be expensive to ship the kit a great distance?
A.

No. The heavy part of the home is concrete and the rebar. We buy the rebar in the destination area in any shipment going over 200 miles to reduce shipping cost. The shipping weight on a 40 foot dome less rebar is under 5,000 pounds, with the heaviest piece weighing 215 pounds and the longest length at 24 feet. We normally ship common carrier.

Q?Will I need a specialized contractor with prior experience in building this type of home?
A.

The simplicity of the kit design enables any local contractor to build the home. We provide factory support for local contractors and do-it-yourselfers and are always available to answer questions. The kit is designed to be installed by non-skilled labor. All holes are drilled and all welding is performed at the fabrication plant. No on-site welding, special fabrication or tools are required. The interior is conventional framing, wiring, plumbing, plaster, etc. Over 80% of our sales are to do-it-yourselfers.

Q?How long will it take to build the home?
A.

Normally 3 to 6 months is required for construction as with any custom-built home.

Q?How much will it cost to build?
A.

Our homes are comparable with conventional homes in cost. Actual cost per square foot varies from $75-$100 for a do-it-yourselfer to over $100 for a very well finished contractor-built home. This cost estimate includes a garage but excludes land costs. Cost is usually about the same as a medium priced custom built home per sq. ft. Example: A 1,000 sq. ft. home = $100,000 if local costs are $100 per sq. ft.

Q?What about financing?
A.

Homes have been financed through FHA, VA and conventional loans. New Energy Efficient Mortgages and other Incentive Programs…

Q?What about building codes?
A.

Our homes are designed to Uniform Building Code standards. We meet all requirements for natural light, ventilation and egress. Our builders have never been denied a building permit.

Q?What soil tests will be required?
A.

You need only a very basic soil test in the area of the foundation, testing for soil type, soil weight, and soil bearing capacity. The soil needs to be tested to a depth of 10 deeper than the depth of the footers. If you’re building in a seismic region, then the engineer will also want to know the type of fault and distance of the home from the fault.

Q?I notice your structure requires Shotcrete. What is it and where would I find someone in my area to do the job?
A.

Shotcrete is simply pumped concrete applied through a hose under pressure. In the past, swimming pool contractors were the primary source of this service. We can help you locate a crew and give you an idea of what is a fair price. These rigs are very mobile and travel well if a crew is not available in your immediate area. Now, however, the people that deliver the concrete may also have the capability to apply the shotcrete themselves, at substantial savings to you. “I did my house using a local concrete pump service, this local concrete pumping company just hooked up the shotcrete nozzle and connected up a compressor for a cost (if I remember right….) of $4 per yard, plus the compressor rental of $125. I have called around the US and found this to be true in other locations. This is a huge savings and people really need to be educated on the optional ways of doing things and how to save a buck or two…” Thanks to Brad Glasse for sharing this advice.

Q?How do I get started?
A.

Start with the DVD/CD package today! Purchase plans well in advance of actual construction. Plans are needed for obtaining financing, a building permit and bids. Then, order the kit thirty to sixty days before construction.

Q?Earth shelters are light, airy, and can maximize views
A.

Building codes require that the glazing area must equal 10% of the floor plan area in any home, ours included. Natural light in the standard models — combined with excellent ventilation and the flowing structural shape –create comfortable, spacious interiors. The arch shape encourages natural air circulation. Views are available by opening the atriums or by building an open-ended model. Also, a cupola may be added to the top of the home for amazing 360-degree views.

Q?Earth shelters are very durable and safe
A.

PBSI structures are built with a very long useful life, and are designed to withstand the effects of tornadoes, hurricanes, earthquakes, explosions and fires. The structures have been tested by each of these perils and have never suffered structural damage.

Q?Earth shelters are very efficient
A.

A well-insulated above-grade home is influenced by outside air temperature, whether the heat of summer or the cold of winter, and is aggravated by wind chill factors. An earth shelter has much less direct, unsheltered, outside exposure, hence less energy requirements.

In addition, an earth-sheltered home enjoys the benefits of a large thermal mass. The concrete foundation and shell are surrounded by “free” earth (often the same earth that was excavated for the foundation). This earth provides a very large thermal mass at little added cost. This thermal mass soaks up and stores the energy that stabilizes interior living temperatures at a comfortable level – eliminating temperature swings. A conventional house may be subjected to outside temperatures ranging from the teens or lower, up to 100 degrees over the course of a year. An earth-sheltered home’s large thermal mass forms an envelope around the home that will stabilize at about 57 degrees on its own.

Simply put, your home is being heated in the winter and cooled in the summer with energy that is free, renewable and produces no pollution.

Q?Earth shelters are very resistant to damage from fires
A.

Unlike a conventional home, the earth-sheltered structure has no combustible roof and fewer exposed external walls. Thus, an earth-sheltered home is much less likely to burn in a forest or brush fire than a conventional home.

Q?Earth shelters are very resistant to extreme weather
A.

Violent weather has no effect on any part of an earth-sheltered structure except for windows and the exposed entry walls, which can be protected by shutters or other devices. Nothing will freeze, even if left for months unheated.

Q?Earth shelters are very resistant to earthquakes
A.

Our structures withstood numerous earthquakes in California and Idaho with no damage even though structures around them were damaged. In fact, earth sheltered structures are very resistant to earthquakes. They can be compared to a submarine riding smoothly beneath rough seas while a conventional above ground structure compares to a surface ship fighting waves.

Q?Earth shelters, when built for maximum protection, provide
A.

In the late 1980’s, one of our designs was involved in a government blast test. Our structure, which was located 600 feet from the center of the blast, experienced no damage from a bomb equal to the size of the Hiroshima atomic bomb. Since then, we built a shelter complex in Montana designed to house approximately 2,000 people. This complex is capable of withstanding an 8.5 magnitude earthquake and a 1-megaton air burst at ground zero. Other smaller shelters also have been built. The protective structures utilizing the PBSI design have few differences from the standard home shell.

In summary, our homes are well protected against extreme temperatures, wind, tornadoes, fire and both natural and man-made disasters. In addition to increased protection and security, PBSI structures offer significant savings on utilities and maintenance – while providing a beautiful, light, comfortable and spacious living environment.

Q?What are the advantages of your arch or dome shaped earth sheltered home design over a more conventional “box” type earth sheltered home?
A.

Theorists have long recognized the thin-shell monolithic dome as the superior earth sheltered design form. However, what stymied the theorists was how to put the complex dome shape into widespread use on a practical and economical basis using conventional concrete forming techniques.PBSI removed that roadblock by providing a solution that eliminated the need for costly and complex concrete forms.

The natural strength advantage of the arch shape is obvious. As our engineer noted, “A flat wall or roof is already half broken when compared to an arch or dome shape.” The PBSI home utilizes a 4″ to 6″ inch wall thickness as opposed to 8 to 12 inches in a box design. Roof thickness is the same, while 14 to 20 inches or more is the norm in a box design roof depending on the span. The box design has many joints which can come apart under the tremendous earth load (wall to foundation joint, wall to wall corner joint, wall to roof joint). The joints are also much more difficult to make watertight than our one-piece shot-on concrete structure. Arch and dome shapes enclose much more floor area in relation to the wall area. This translates into less construction material used and less temperature influence from the outside. Further advantages are improved air circulation and a lack of interior supports and buttress walls giving greater floor plan versatility. The arch reflects natural or artificial light to the center of the structure for a brighter interior.