The delivery model that makes complex UHPC facade projects work. Early engagement isn't optional — it's how you protect the design intent, the schedule, and the budget simultaneously.
Design-assist is a procurement model in which the facade contractor or specialist subcontractor is engaged during the design phase — before construction documents are issued — to contribute technical input, refine constructability, and establish a reliable budget and schedule. It is not design-build: the architect retains design authority. It is not early bidding: the contractor is contributing expertise, not just pricing.
In practice, design-assist for UHPC facades means the architect and facade contractor are working collaboratively from schematic design or early design development. Connection geometry, panel sizing, tolerances, mock-up strategy, and engineering coordination are resolved before they become change orders. The result is a facade that is both more buildable and more faithful to design intent than one specified in isolation and bid competitively at construction documents.
"UHPC's tight tolerances and connection geometry are interdependent. Resolve them collaboratively in design. Discover them in the field and you have a problem."
Every facade system benefits from design-assist. UHPC particularly requires it for three reasons.
First, connection geometry and panel geometry are not independent. Where anchors land within a 25mm panel — and how they relate to panel edge conditions, reveals, and mold geometry — must be resolved before fabrication. Changes discovered in shop drawings are expensive. Changes discovered in the field are worse.
Second, UHPC mock-up programs are longer than conventional precast. Full-scale mock-up panels need to be produced, reviewed for finish and color consistency, and approved before production starts. The underlying reason is the manufacturing sequence — mold development, cure cycle, and post-processing — which cannot be compressed below a minimum of 6–8 weeks for custom panels. If mock-up approval is on the critical path, and design-assist engagement starts at CD, the schedule is already compromised.
Third, the interface between UHPC panels and adjacent systems — curtain wall, windows, waterproofing — requires coordinated BIM modeling at a level of detail that conventional precast doesn't always demand. Starting that coordination at permit review, rather than at design development, is a preventable risk.
| Phase | Design-Assist Activity | Outputs |
|---|---|---|
| Schematic Design | Initial system evaluation; panel sizing options; budget range; program fit assessment | Preliminary budget; system recommendation memo; engagement agreement |
| Design Development | Panel layout coordination; connection system selection; BIM model initiation; interface coordination with structural and curtain wall | Panel layout drawing; connection concept sketches; updated GMP or budget |
| Construction Documents | Connection engineering; full BIM coordination; specification section development; mock-up program definition | Issued-for-permit shop drawings (preliminary); specification section; mock-up scope |
| Permit / Pre-Construction | Mock-up production and approval; engineering stamping; shop drawing issuance and review | Approved mock-up; IFC shop drawings; fabrication schedule |
| Fabrication | Panel production; quality control; shipping logistics coordination | Panels ready for delivery per erection sequence |
| Erection | Sequenced installation; field coordination; punch list | Substantial completion; warranty documentation |
A qualified UHPC facade design-assist partner should be able to provide: preliminary panel layout drawings within 2–3 weeks of engagement; a budgetary estimate based on that layout; connection concept options with relative cost implications; a mock-up program recommendation; and an honest assessment of schedule risk if engagement starts late.
What they should not do is use design-assist engagement as an opportunity to lock in the project without competitive tension. Design-assist agreements should include clear scope, fee structure, and an explicit decision point at the transition to construction — preserving owner leverage while compensating the contractor fairly for preconstruction effort.
UHPC facade design-assist projects are BIM projects. Panel geometry, connection hardware, anchor penetrations, substrate conditions, and adjacent system interfaces all need to be modeled at a level of detail that supports coordinated shop drawings. LOD 350–400 for facade elements is typical by the end of design development.
The BIM model is also the primary tool for tolerance management — verifying that the building frame is within the tolerances the panel connections can absorb, and identifying locations where frame correction will be needed before panels arrive.
Starting a project? The earlier the conversation, the better the outcome. Get in touch → — describe the project, the stage you're at, and the program type. We'll give you an honest read on timing, budget range, and process.
Application survey across facades, structural elements, and specialty systems.