Custom Fabricated Conventional Structural Prefabricated Steel Pre-Engineered Building

Pre Engineered Steel Buildings

Conventional Structural Steel Buildings

1) Design Criteria ISO Universal

1) Design Criteria normal domestic standard

2) Design: Quick and efficient since standardization of pre-engineered steel buildings has significantly reduced design time. Basic designs are used over Specialized computer analysis and design programs reduce design time and optimize material required. Drafting is also computerized with minimal manual drawings. Design, detail drawings and erection drawings are supplied free of charge by the manufacturer. Approval drawings may be prepared within ten days to 3 weeks. Consultant in-house design and drafting design is significantly reduced, allowing more time for coordination and review, and increasing margins in design fee savings.

2) Design: Each conventional steel structure is designed from scratch by the consultant, with fewer design aids available to the Engineer. Maximum engineering required on every project. Generalized computer analysis programs require extensive input/output and design iterations. Drafting is manual or only partially automated.Much Consultant time and expense is devoted to design and drafting, as well as coordination and review.

3) Weight: About 30% lighter through the efficient use of steel. Primary framing members are designed with tapered built-up plate sections with the most steel in the areas of highest stress, using high strength steel.Secondary members are light gage cold formed “Z” or “C” shaped members. Members are roll-formed for minimum weight and labor cost.

3) Weight: Steel member sizes must be selected from standard hot rolled sections, which in many cases are heavier than what is actually required by design. Members are the same cross-section along the entire length, regardless of local stress magnitude  Secondary members are from standard hot rolled “I” and “C” sections. In many cases members are heavier than required, and therefore are not as economical as cold formed members.

4) Base Material: Rigid Building pre-engineered steel buildings system uses almost all steel to meet 50,000 P.S.l. minimum yield including the cladding.

4) Base Material: In most of the cases (90%) Base Material is 36,000 P.S.I. minimum yield.

5) Foundation: Simple design, easy to construct and lightweight.

5) Foundation: Extensive heavy foundation required.

6) Accessories (Windows, Doors, Ventilation): Designed to fit the system, with standardized, interchangeable parts, including pre-designed flashing and trims.Mass produced for economy. All available with the building.

6) Accessories (Windows, Doors, Ventilation): Every project requires special design for accessories and special sourcing for each.Flashing and trims must be uniquely designed and fabricated.

7) Delivery: much faster

7) Delivery: longer time

8) Erection: Easy, fast, step by step. Erection costs and time are accurately known, based upon extensive experience with similar buildings.

8) Erection: Slow, extensive field labor required. Typically 20% more expensive than pre-engineered steel buildingss
In most of the cases, the erection cost and time are not estimated accurately.

9) Architecture: Outstanding architectural design can be achieved at low cost. Conventional wall and fascia materials, such as concrete, masonry and wood, can be utilized.

9) Architecture: Special architectural design requires research and high cost.

10) Overall Price: Price per square meter may be as much as 40% lower than conventional steel.

10) Overall Price: High price per square meter.

11) Sourcing and Coordination: Building is supplied complete with cladding and all accessories, including erection if required, all from one source of supply.

11) Sourcing and Coordination: Many sources of supply. Project Management time required to co-ordinate suppliers and sub-contractors.

12) Changes: Very flexible, tailor made, accepts changes and revisions easily. Future expansion simple, easy and cost effective. One supplier to coordinate changes.

12) Changes: Changes, revisions and additions can be difficult due to extensive redesign and coordination among suppliers and subcontractors.

13) Responsibility: Single source of supply results in total responsibility for one supplier, including design liability.

13) Responsibility: Multiple responsibilities can result in questions of who is responsible when components do not fit properly, insufficient material is supplied, or materials fail to perform, particularly at supplier interfaces. The Consultant carries total design liability.

14) PerformanceAll components have been specified and designed specifically to act together as a system, for maximum efficiency, precise fitup, and performance in the field.The experience with similar buildings in actual field conditions world-wide has resulted in design improvements over time which allow dependable prediction of performance.

14) PerformanceComponents are designed in general for possible use in many alternative configurations. Design and detailing  errors are possible in assembling diverse components into unique buildings.Each building design is unique, so prediction of how components will perform together is uncertain. Materials which have performed well in some climates may not in other environments.