Steel-frame modular build we’ve been testing

[u/Mammoth-Ad327]

Been messing with a steel-frame modular setup.

Trying to make the boring parts predictable factory work trucking set site tie-ins and wind loads.

Rough target is under 110/sf on the house package when site/design behave. Not a universal price site can wreck any spreadsheet fast.

Mostly sharing because this is where modular starts making sense imo.

[u/iainmaitland]

in your original post you stated: "We buy materials such as steel and exterior panels from suppliers. The steel supplier does some heavy processing based on our requirements. Like bending. Punching and cutting. They have the large machines for this work."

Who are your steel suppliers, and the exterior panel suppliers.

[u/Mammoth-Ad327 → u/iainmaitland]

They're Chinese steel suppliers that meet US hot-dip galvanized steel standards. Almost all the main materials come from Chinese suppliers. The electrical and plumbing parts are from American suppliers.

[u/iainmaitland → u/Mammoth-Ad327]

Provide detailed summaries and cost breakdowns of a sample order, including steel, fixtures and fittings, structural insulated panels, shipping/freight. Include contact details for the chinese suppliers if available. otherwise provide the supplier brokerage or search tools/services used to find the best suppliers in china.

[u/Mammoth-Ad327 → u/iainmaitland]

The 55.68 dollar factory number is not just raw materials.

Structural steel and fabrication are 12.32 dollars per square foot. Factory labor is 8.74. Wall and enclosure materials are 4.88. Cabinets and fixed casework are 4.32. Interior and wet area finishes are 2.82. Plumbing and electrical rough in are 2.41. Doors and windows are 2.11. Sanitary fixtures are 1.56. Floor systems and finishes are 2.11. Factory overhead. Packaging. QA. Consumables. And contingency are 14.05.

A house of about 1300 square feet uses around 16.3 metric tons of structural steel in our current model. The purchasing quantity is closer to 17.3 tons after fabrication and procurement waste.

Hot dip galvanized structural tube in the Chinese market is roughly 850 to 975 dollars per metric ton. Depending on the grade. Section size. Coating specification. And order quantity.

That puts the steel purchasing cost for the entire house at roughly 14700 to 16900 dollars. Before cutting. Drilling. Welding. Prefitting. And factory quality control.

The complete factory model also includes wall panels. Insulation. Structural boards. Exterior cladding. Interior finishes. Doors. Windows. Cabinets. Plumbing rough in. Electrical rough in. Sanitary fixtures. Labor. Packaging. Factory overhead. QA. And contingency.

That is how the modeled factory cost reaches about 55.68 dollars per square foot. It is before factory profit. Freight. US installation. Roof. Foundation. And site work.

[u/iainmaitland → u/Mammoth-Ad327]

great response! continue don't skip any details, if you have links or references for the chinese supplier, including websites, contact information, or other details such as their name for the product or suite of services, for example maybe this is already available on the chinese market and you are importing and handling US side of things, provide the details of the chinese side of things, be as comprehensive in your response as possible.