pilings and platform

Have you checked with your local building department to see what they require your house be built on? If you live near the ocean or water, the building department may require concrete pilings which are usually driven 10' to 15' down into the ground versus concrete columns that only go down about 3' into the ground. 

When there is a potential for waves of water washing dirt out from under your house, the local building department usually requires pilings. If your property is within a few hundred feet of the ocean or gulf then it is the federal government that decides what foundation type your house will have. If you have neighbors that are currently building, ask them what foundations they are utilizing.

Whether you use concrete pilings or concrete columns, we can design a wood platform under the dome and a deck made out of plastic wood or pressure treated wood. Or we can design for a concrete platform. Remember your building department will require the piling and platform plans and the dome plans to be engineer sealed. These seals can be purchased through us.

Once you know which types of stilts and platform are acceptable by your building department, the next step is to ask the Building Department and or your friends, neighbors, relatives that have built on stilts and a platform for contractor references.  Contact two or three of these stilts/platform contractors and obtain pricing quotes for a platform the square footage of the dome home you are planning....1,178 sq.ft. for 40', 916 sq.ft. for 36', 1,489 sq.ft. for a 45' dome....adding in whatever deck and patio area that you want.

We think the prices will shock you!  That is why you are shopping types of stilts and platforms and different size domes so you can get an idea of construction costs.  To keep your costs down, we recommend that you build as small a dome as you can because stilts and platform costs can range from $30,000 to $60,000 and that pricing does not include the costs for the dome kit, materials to finish the dome or any labor to assemble the dome kit and finish its interior.  While you are at it, ask the contractors what the approximate cost per sq.ft. is to finish a conventional house in the neighborhood where you are thinking of building.  Once you have this number then you can really decide what size dome you can afford to finish. The dome size will ultimately determine the size of your platform.

If you need to obtain financing, the lender will require 20% to 30% down based on the finished price of your stilts/platform and the dome.  So if you build a 36' dome (about 1,664 sq.ft.) and the price per sq.ft. to build is $100; then the finished price of the dome (this includes the kit costs) is around $165,000. Plus add in the stilts and platform cost of $30,000 to $60,000 to come up with costs of $195,000 to $225,000.  The lender will want $39,000 to $68,000 down.  They will accept some equity you have in the land, but they will want alot of cash to be included in the down payment.  Is this down payment within your budget?

We hope we are not bursting your bubble....but over the 30 years that American Ingenuity has been in existence, we have found it better to be up front on the "big picture"; so that our clients do not purchase building plans for too large a size dome and then later not be able to afford to finish their dream home.  To us the single biggest bargain our clients receive is the American Ingenuity Dome building kit...which is usually one half less in cost than the materials cost for the walls and roof of a conventional house or wooden dome or gunited concrete dome.....but this does not mean that all the finishing costs will be one half less.  The kitchen cabinets, doors, windows, plumber, electrician, stilts, platform, etc. all cost the same whether it is a box house or a dome.  So it is best to build the smallest dome you can and even consider not installing the second floor till later.  That way you can afford to finish your dome, live on your  property and save month to month on your heating and cooling costs and have a tornado, hurricane, earthquake proof house!

As far as selecting a contractor for your dome, we recommend that you get quotes from several builders to compare construction costs....all the time explaining to them that they need to quote you based on hiring the Kit Assembly Consultant to supervise their workers to get the shell assembled.  Once you have determined your floor plan, our Operations Manager can give you an agreement as to the number of days the consultant is needed.  This way the contractor does not need to be worried about estimating the assembly costs and making mistakes during the assembly just because he has never assembled and AI dome kit before.  Once the dome is erected, and a scratch coat of concrete is in all the seams and on all the entryways and dormers, the Consultant can leave and the contractor's subs can finish the interior and even finish the last coat of stucco in the seams and on the entryways and dormers.  

I think I need to build my foundation off the ground.

First of all, how high off the ground does the first floor have to be? If you do not know this answer, you will need to call your building department and ask them.

Possible Solutions:

1. If your dome has to be eight feet to ten feet off the ground:
   1. Due to a wave of water, not rising water then the dome will have to be built on concrete columns and a concrete or wood platform
   2. If you want enclosed rooms or a garage under the platform, then you can install break-a-way walls.
   3. Due to rising water
      1. Build an above ground basement
      2. Build concrete block columns under the corners of the platform.
2. If your dome has to be raised two to three feet, the best thing may be to bring in fill and construct the concrete slab onto the fill.
3. If your dome has to be raised two to three feet build a stem wall:
   1. bring in fill to fill within the stem wall and pour a concrete slab onto of the fill (most economical and energy efficient)
   2. install a wood floor that sets on piers and beams. You would have a crawl space. (more expensive)

Q: In my area I have to deal with the possibility of a wave surge, can I build my dome on "break away basement walls"?
A: Yes. If you have to design with the possibility of a wave surge, you may be able to enclose the first floor pilings with breakaway walls. Breakaway walls are nonstructural walls that will break-a-way in the event of a wave surge. Pilings (columns) would support the structure and the breakaway walls could be installed between the pilings to enclose the ground floor. The purpose is to enclose the ground floor but preserve the house if a wave tears down the walls.

Q: In my area I have to build on pilings and a platform. Can the dome be built on pilings and still maintain its structural integrity?
A: Yes, building our dome upon pilings does not effect the dome's structural integrity. We can design the pilings and the platform, but you will need an engineer licensed for your state to seal the Piling Blueprints. For example, the Building Plans Cost for the pilings and concrete platform for a 45' dome could be more than $2,000.....this pricing does not include the building plans for the 45 dome home itself.  We know of a Florida engineer who charges from $1,000 to $2,000 to seal the pilings and platform plan.

If you built the dome on the ground using a concrete slab, the plans would only be about $1,000 and the engineering would be about $500. All the costs associated with elevating any house onto pilings is considerable more and worth considering other options.

For a complete summary of all types of foundations that can be used with the American Ingenuity Dome, click on this link Foundation Summary.