PO BOX 111
Elkwood, VA 22718 USA
+1 540 349 5895

General FAQ

What is the am-cor System?

The am‑cor System™ is a modern, Ferrocement construction system, featuring:

  • true composite, integrated steel & cement structures
  • unibody, seamless, exterior stress-skins
  • high flexibility & adaptability
  • high strength-to-weight ratio

The am-cor System is a simple, fast, affordable way to build green & sustainable buildings. Architect Angus W. Macdonald invented & patented the am‑cor Unified Steel & Cement Structural System after searching for after searching for a better alternative to standard construction methods. He wanted something that was simple to construct, quick to erect, cheap to build, and above all, beautiful, durable and sustainable.

The am‑co System is tried and proven: am-cor structures have weathered tornadoes in USA’s Tornado Alley, hurricanes in the Caribbean, and floods on Virginia’s Eastern Shore. Our building shells are internationally code compliant, and has been approved by the US Army Corps of Engineers for construction in storm surge areas.

How do I use the am-cor System?

We manufacture am-cor System panelized ferrocement construction Kits, called am-cor Kits. These Kits are shipped to your building site, where they are assembled to create a steel frame which is then coated with amcorite ferrocement mixture to create a unibody building shell.

You can order one of standard plan Kits, or design your own. Most of our clients hire a builder/contractor to assemble their Kits, but you can also do it yourself (DIY).

See also:
Why use the am-cor System?

You should build with the am-cor System because:

Inexpensiveam-cor construction is less expensive than: standard reinforced concrete block & masonry, precast, metal buildings, stick-built, SIPS, etc.
Fast To Buildam-cor Kits are: prefabricated & pre-engineered, arrive ready for immediate assembly, and are assembled in a fraction of standard construction time
High Qualityam-cor buildings are better construction for a lower price: disaster resistant (hurricane, fire, tornado, earthquake, flood); mold, mildew, insect & vermin resistant (termites, rats, etc.); and environmentally friendly
Green & Sustainableam-cor shells are made of 100% recyclable material, and have an approx. 60-80% lower carbon footprint than standard construction; am-cor buildings are inherently sustainable, and require virtually zero maintenance


Normally, building constructing can be quite challenging, even for professionals! Things are even more difficult if you want to build your own home. We aim to make the entire construction process much simpler:

  • The am-cor System reduces the number of steps & complexity
  • Each am-cor Kit comes with a detailed Field Manual, describing & aiding construction from start to finish
  • Much less labor/material/waste is involved in am-cor construction
  • A contractor / builder can spend much less time on site, and only needs experienced tradesmen for code requirements (e.g.: electrician, plumber)
  • A home-owner can DIY much construction, except for trades required by code (e.g.: electrician, plumber)
What exactly is Ferrocement?

Ferrocement is a construction method, characterized by highly reinforced, composite cement & steel, thin concrete shells. It is not new technology; in fact, Ferrocement & standard reinforced concrete construction were invented & patented in the same country and time period: 19th century France. While reinforced concrete was quickly adapted to building construction, Ferrocement was initially used in boat hull construction.

Check out the Overview of the am-cor System and our section on Ferrocement.

What exactly is amcorite?
amcorite™ is a proprietary Ferrocement admixture. Developed by Angus W. Macdonald in collaboration with one of the world's leading cementologists, amcorite has seen years of field testing and refinement.

amcorite's properties:
  • Can be mixed with standard, affordable, readily-available ingredients: Portland cement, water, and sand.
  • Creates a thin, extremely strong, Ferrocement structural stucco-like stress-skin.
  • Increases workability & ease of application over traditional mixes.
  • Sets quickly; increases strength over time.
In comparison to standard Ferrocement mixtures, one of the main advantages of the amcorite/Portland/sand mix is that it is remarkably forgiving: easy to mix, easy to work with & apply, and hard to get wrong - with any type of sand.
In fact, amcorite is the "secret sauce" in the am-cor System: many have tried to replicate the am-cor System's signature disaster-resistant, thin, high strength Ferrocement structural stress-skins, but have failed. Their buildings crack, spall, or are expensively overstructured; in fact, one competitor's building even collapsed!

Learn more about amcorite and the am-cor System's capabilities in our System section.
Is Ferrocement new technology?
No! Ferrocement is tried and true technology: very strong, and very durable.

The am-cor System's patents & technology allow Ferrocement to be used for mass production of lightweight, durable & sustainable panelized building Kits. Bringing Ferrocement construction methods into the mainstream solves many problems facing today's construction industry, and the world.

Check out the Overview of the am-cor System and our section on Ferrocement.
How is the am-cor System green & sustainable?
The am-cor System's Ferrocement structural skin has a number of interesting properties.  The structural exterior surface of am-cor buildings is a seamless, unibody, highly reinforced steel & cement composite, which allows for:
  • Far less material used than standard construction:
    • 1/8 cement
    • 20% less steel
  • Complete in 2/3 time of standard construction
  • Sustainability: approximately 40% smaller carbon footprint
  • High durability
    • Disaster resistance integrated into building structure
    • Extremely low maintenance over the building's lifetime
See our section on Green & Sustainable Construction for more, including information on LEED credits.
What are your goals?

am-cor inc. aims to change the world one building at a time. We believe that through a combination of global thinking, environmental awareness, and construction innovation, people can inexpensively build green, sustainable, and beautiful buildings that will withstand natural disasters, rising energy prices, and the test of time.

Can I fix an existing building with your System?
Yes!

am‑cor ExoStructures can be used to:
  • Quickly fix any existing structure: metal, concrete, masonry, wood, etc.
  • Inexpensively add structural integrity (far cheaper than replacement)
  • Add weatherproofing, moisture & air barriers, superinsulation, and earth-tempering.
See our am‑cor ExoStructures section.

Installation of ExoStructure w/insulation around existing building

Installation of ExoStructure w/insulation around existing building

How long do am-cor buildings last?
If our calculations are correct, am-cor structures should last as long as the Roman Pantheon, which is approximately 2000 years old.
How long have you been in business?
am-cor inc. was founded 2000. Angus W. Macdonald patented the am-cor System in 1996. The oldest am-cor structure is a residence built in 1996, and is inhabited by the original happy owners.
Do you ship internationally?
Yes, we are happy to ship internationally. Orders to Mexico & Canada are usually filled by flatbed or enclosed trucks. International orders not in the continental USA are sent by container ship.
I want a factory to make am-cor Kits in my region/country. How do I get started?
Please contact us. There are a number of FerroFacility setups available, depending on on your needs. Be prepared to provide am-cor inc. with some data regarding your Kit manufacturing project:
  • Estimated annual quantity of am-cor Kits to be sold
  • Estimated annual Kit floor area production (M2 or sq.ft. of combined total building area)
  • Anticipated building type of the majority of the Kits you intend to produce
  • Your group's capabilities in the region
  • Access to industrial raw land for FerroFacility construction, or industrial space for lease
Costs can vary depending on regional variations in labor, materials, tariffs, taxes, security, etc.
As a general benchmark, basic low cost am-cor house Kits in emerging economies can be locally manufactured, assembled, and finished for approximately US $20/sq.ft., or US $215/M2.
Last updated 2011-02.

In each FerroFacility Kit, we provide a complete, end-to-end setup program, including:
  • Everything included in a standard am-cor Kit
  • Quick construction of a FerroFacility using local labor & materials
  • Simplified mass production of am-cor Ferrocement Kits
  • Zero energy factory building (off-grid)
  • Zero energy manufacturing equipment
  • CNC link to Kit design stations, raw material inventory, production progress
  • Kit manufacturing crew training
  • Kit design training
  • Kit field assembly crew training
am-cor inc. manages production in your FerroFacility, ensuring optimum efficiency, advanced quality control, and free assembly line software, hardware, and panel technology upgrades.
    I'm a builder/contractor, and I want to build am-cor Kits. How do I get started?
    We provide contractors & builders with free, on-the-job crew training during construction of your first am-cor Kit.  Once your crew has successfully completed and enclosed an am-cor structural shell, we'll certify you as an am-cor Builder. We'll also refer you to Kit purchasers in your region. Check out the Contractors section for more.

    Interested in suggesting am-cor Kits to your clients? Contact us about customized builder classes, tutorials, and contractor discounts.
    I'm a designer/architect, and I want to design an am-cor Kit. How do I get started?
    Great! You'll love the am-cor System, as it was developed by an architect, for architects. Designers, Architects and Engineers are welcome to design am-cor buildings for their clients and for publication on the net as standard am-cor Kit plan sets.

    Check out our  Architects & Engineers section, our Designs section, and contact am-cor inc. for a downloadable pdf of the am-cor Specification and the am-cor Design Manual.
    I want to use the am-cor System for my home/office/development. How do I get started?
    Contact us with your plans and ideas for pricing, and see our Developers section!
    If you already have a site or building plan, or have a general idea of what you want, check out our section on Designs and Pricing.

    Your am-cor Kit is engineered in accordance with your plans.  We can consult with you, your architect/engineer, and your contractor for the most efficient structure and greatest energy savings. All am-cor Kits are fully code-compliant, and we'll ensure our plans are acceptable to your local code authority: your Kit includes an am-cor Structural Set , which is compiled with your architectural drawings for permit submission.

    We help ensure fast, easy structural approval.
    Do you provide financing for your Kits?

    No, am-cor inc. does not provide financing.

    Our clients have had no trouble financing their projects through standard mortgages, and we provide full support to help qualify prefab/modular loans.

    We also have experience finding funding if you are planning a larger development or an overseas project, especially for low-cost housing in the developing world.

    Contact us for more information!

    Is Ferrocement really disaster resistant?

    Yes. The Ferrocement am-cor Unified Steel & Cement Construction system is resistant to:

    • hurricanes
    • earthquakes
    • tornados
    • flood
    • fire

    The am-cor System is extremely strong, due to the true composite nature of Ferrocement. The steel & cement are structurally unified into a single, seamless stress-skin building shell, which does not rely on fasteners or joints (e.g.: screws, nails, bolts, etc.), as in standard construction, and is directly integrated into the building's foundation. The building's Ferrocement skin is the structure. As such, forces inflicted on the building's structural skin during a natural disaster are distributed throughout the stress-skin, even to the foundation.


    See our Disaster section for more information and real world examples.

    Can Ferrocement provide low-cost housing in the developing world?
    Yes.  Ferrocement technology, as used in the am-cor Unified Steel & Cement System:
    • uses less raw material
    • fast to assemble & complete
    • can be assembled by unskilled labor
    • easy to transport to remote sites (Kits can kit in one or more pickup trucks)
    • minimal site disturbance
    • low Carbon footprint
    • most durable, VOC free, disaster resistant, and energy efficient construction type in the low cost permanent product range.
    In developing nations, am-cor affordable housing Kits can be manufactured locally in an am-cor FerroFacility, sold for about US $10/sq.ft. and completed for another US $10/sq.ft.  This total of US $20/sq.ft. for durable, disaster-resistant structures is a UN and World Bank benchmark for low cost housing, which up to now has not been consistently achieved for mass produced, beautiful, durable, healthy and safe housing.
    Last updated 2011-02.

    See also:
    Is the am-cor System cost competitive in developing economies?
    Yes: when produced in a local FerroFacility, using local labor, and when compared with other permanent durable and disaster resistant construction types, the am-cor System is definitely cost competitive in developing economies.

    The overall cost of construction: including site preparation, site cleanup, cartage of waste, time, project overheads, and material allotment, is much lower using the am-cor System than any other method.

    The reason for this lies in the innovative geometry of the patented am-cor panel design and building shell design:
    • Ferrocement structural material does not fill the panel, but creates a continuous stress skin, leaving the inside hollow
    • Lightweight panel design and utilization of local sand, cement & water lowers transportation, and keeps material costs low
    • Easy to snap-together panels save assembly time and cost, utilizing untrained labor to quickly assemble Kits
    • The thin seamless Ferrocement coating joins all panels together to create a single structural unit, the shape of the entire building shell
    • Each room in the building becomes a structural cell in an emerging market nation
    • The structure is embedded in the building foundation in a way to resist flooding, hurricane, tornado and earthquake
    am-cor FerroFacility assembly line design incorporates completely integrated design/manufacture methods, to ensure consistent quality Kit production on schedule, and under budget.

    The am-cor product line of efficient and beautiful schools, homes, community structures, hospitals, marine and other building types provides durable life safety structures at the most competitive cost.

    Contact us for more information.
    When you say prefab…
    We know what you're thinking!

    am‑cor Ferrocement structures differ from other "prefab houses". Our buildings are:
    • Extremely strong and durable, not cheap or flimsy
    • Made of high quality, long-lasting materials (steel & cement)
    • Truly safe and disaster-resistant
    • Factory-made to exact dimensions & specifications
    The am‑cor System is prefabricated in that all Kit components (wall, roof, floor panels, fasteners, etc.) are factory made to precise specifications. Each am‑cor Kit is assembled and coated with Ferrocement on site, producing a strong, durable structure.

    See also:

      Have a question that's not answered in the FAQ? Let us know! You can also search this site for your question.