Membrane structure cost per square metre: comparing quotations

Typical parts of a project quotation

Itemise survey and design, foundations and embedded items, steel fabrication and protection, membrane fabrication, connections and drainage, transport and lifting, installation and handover. State separately whether lighting, electrical work, equipment, demolition and ground reinstatement are included. Membrane purchase price is not a complete project unit price.

• Specify material manufacturer, model, specification, quotation date and validity.
• Define the pricing scope for foundations, earthworks, transport and lifting equipment.
• State taxes, site coordination, warranty and maintenance scope, and how changes are priced.

Different area definitions prevent direct unit-price comparisons

Horizontal roof projection, developed membrane surface and fabrication material area are different quantities. Curvature, cutting layouts and connections affect material use; a universal multiplier is inappropriate. Before dividing total cost by area, check both the denominator and included work.

Conditions that change the budget

Spans, columns, foundations, material models, edge and drainage complexity, transport access, lifting space and work hours affect cost. Refurbishment may add demolition, equipment protection and reinstatement. A rendering alone cannot determine a final settlement price.

Useful information for an initial enquiry

Provide the project city, use, dimensioned plan or sketch, site photos, facilities to retain and desired completion date. Identify drawing revisions and use the same brief for each supplier so design and price differences can be compared.

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