The phases of an architecture project are the stages a building moves through from idea to occupancy: pre-design, schematic design (SD), design development (DD), construction documents (CD), bidding or negotiation, and construction administration (CA). Each phase ends with an owner approval, and each one fixes decisions the next phase builds on.
The sequence matters because it controls when change is cheap. Moving a wall in schematic design costs an afternoon. Moving the same wall after the steel is ordered costs a change order, a schedule slip and an argument about who pays. Knowing what each phase settles helps you read a fee proposal and explain why a "small tweak" in month nine is not small. Below, each of the architecture project phases is broken down by the question it answers, what it produces and how much of the fee it usually carries.
Why Architects Split a Project Into Phases
Phasing is a way of buying certainty in steps. The owner commits money in installments, and the architect gets a signed approval before investing effort in the next level of detail. The American Institute of Architects describes five phases of basic services in its guide to the architect's basic services: schematic design, design development, construction documents, bid or negotiation, and contract administration. Pre-design sits in front of those five and is usually contracted on its own.
The phases also map onto how firms bill. Most owner architect agreements, including the AIA forms covered in our guide to AIA contract documents, let the parties tie payments to phase completion. That is why a phase name on an invoice is more than a label: it signals that a specific body of decisions is now considered settled.
Outside the United States the names change but the logic holds. The RIBA Plan of Work 2020 uses eight numbered stages, from Stage 0 Strategic Definition to Stage 7 Use. Its Stages 2, 3 and 4 (Concept Design, Spatial Coordination and Technical Design) line up roughly with SD, DD and CD.
Pre-Design: Defining the Problem Before Drawing It
Pre-design answers one question: what exactly are we building, where, and for how much? It covers site analysis, zoning research, feasibility studies and, above all, programming. Western Michigan University's facilities office sums up its programming phase as estimating a realistic project cost, determining building and user requirements, and establishing a total building area.
The output is a written program: a list of spaces with target areas, adjacency requirements, performance goals and a budget. On small residential jobs this may be two pages produced in a single meeting. On a hospital or a laboratory it can be a separate consulting contract that runs for months. If you want a closer look at how that document is structured, our article on the architecture design brief walks through it.
Because pre-design varies so much in size, public owners often keep it outside the basic fee. Washington State's Office of Financial Management, for example, treats predesign as distinct from the phases covered by its standard architect and engineer fee schedule.
Schematic Design (SD): Choosing the Big Moves
Schematic design turns the program into a building. The architect tests site placement, massing, floor plate layout and circulation, and compares options until the owner picks one direction. AIA notes that SD is also when zoning requirements and jurisdictional restrictions are discovered and addressed.
Typical deliverables are a site plan, floor plans, a few sections and elevations, massing models or renderings, and a preliminary cost estimate. Dimensions are overall rather than detailed. The phase closes when the owner signs off on the scheme and the estimate.
We cover this phase in depth in What Is Schematic Design?, including what SD locks in and what it leaves open, so here it is enough to say that SD is where the cheapest and most consequential decisions are made.
Design Development (DD): Making the Scheme Work
Design development asks whether the approved scheme can actually be built as drawn, and it answers by bringing every discipline into the model. Structural grids are fixed, mechanical rooms and shafts are sized, ceiling heights are checked against ductwork, and the envelope gets real wall types. AIA describes DD as the phase that lays out mechanical, electrical, plumbing, structural and architectural details.
The drawings grow from diagrams into floor plans, sections and elevations with full dimensions, and, in AIA's words, typically include door and window details and outline material specifications. Interior finishes are selected, major equipment is chosen, and the cost estimate is updated with far more line items than at SD.
DD is also where the budget usually hurts. A scheme that priced well as a massing model may come back over budget once the curtain wall, the structure and the systems are quantified. That is the moment for value engineering, while the changes are still drawn in pencil rather than cast in concrete.
💡 Pro Tip
Close every phase with a one-page approval memo listing what the owner has signed off: area, budget, structural system, facade type, major finishes. When a request arrives three months later that contradicts that list, you have a dated reference point for treating it as a change in scope rather than routine design work.
Construction Documents (CD): Drawing the Building for Someone Else
Construction documents change the audience. Up to DD, drawings mostly persuade and coordinate. From CD onward, they instruct a contractor who was not in any of your meetings. AIA defines the deliverable as a set of drawings that includes all pertinent information the contractor needs to price and build the project.
The CD set adds wall sections, enlarged plans, details, schedules for doors, windows and finishes, and fully coordinated engineering sheets. It also includes the project manual, the written specifications that tell the contractor which products, standards and installation methods apply. Most US offices organize that manual by CSI MasterFormat divisions, which we explain in Specifications in Construction: MasterFormat Basics.
CD is the most labor-heavy phase because every line has to agree with every other line. A door shown on the plan needs a matching tag, a schedule entry, a hardware set, a detail at the head and sill, and a spec section. Offices save real hours here by keeping clean, standardized CAD blocks and detail libraries, so drafters coordinate rather than redraw. The set is then submitted for permit review, and plan check comments are folded back into it before bidding.
SD, DD and CD at a Glance
The three design phases differ mainly in who reads the drawings and how fixed the decisions are. The table below compares them side by side.
| Aspect | Schematic Design | Design Development | Construction Documents |
|---|---|---|---|
| Main question | What is the building? | Does the scheme work with all systems? | How exactly is it built? |
| Primary reader | Owner | Owner and consultants | Contractor and building department |
| Drawings | Site plan, plans, massing, overall dimensions | Fully dimensioned plans, sections, elevations | Details, schedules, coordinated engineering sheets |
| Specifications | Design intent only | Outline specifications | Full project manual |
| Cost estimate | Preliminary, area based | Updated with systems and finishes | Replaced by contractor bids |
| Rough RIBA 2020 equivalent | Stage 2 Concept Design | Stage 3 Spatial Coordination | Stage 4 Technical Design |
Bidding and Negotiation: Turning Drawings Into a Contract
This phase converts the CD set into a signed construction contract. AIA lists its first step as preparing the bid documents that go out to potential contractors for pricing. On a competitively bid job, the architect helps prequalify bidders, runs a pre-bid meeting, answers bidder questions and issues addenda when the documents need clarifying or correcting. Bids are opened, compared and checked for gaps, and the owner awards the contract.
On a negotiated job, the owner picks one contractor and the price is worked out through rounds of pricing and scope discussion instead of sealed bids. Which path a project takes depends on its delivery method. Under design-bid-build, bidding is a distinct phase after CD. Under design-build or construction manager at risk, a contractor is involved much earlier and pricing overlaps with design. Our comparison of design-bid-build vs design-build covers how that shifts the phase boundaries.
📌 Did You Know?
The AIA B101 owner architect agreement does not call this phase "bidding." AIA Contract Documents' summary of B101 lists the five phases of basic services as Schematic Design, Design Development, Construction Documents, Procurement and Construction. "Procurement" covers both competitive bidding and negotiated contracts under one heading.
Construction Administration (CA): Protecting the Design on Site
Construction administration is the phase most clients underestimate and most architects find the busiest. The building is now in the contractor's hands, and the architect's job, in AIA's description, is to help the contractor build the project as specified in the approved construction documents.
The work is steady and reactive. The architect reviews shop drawings, product data and samples against the specifications. Contractors send questions through requests for information (RFIs), and the architect answers with clarifications or supplemental sketches. Site visits check that work generally conforms to the documents. Each month the contractor's payment application is reviewed and certified. Near the end, the architect inspects for substantial completion and issues a punch list of items to fix. AIA marks the end of contract administration with the final certificate for payment.
CA does not mean the architect supervises construction. Means, methods, sequencing and site safety stay with the contractor under the standard AIA forms. The architect observes and reports; the contractor directs the work.
⚠️ Common Mistake to Avoid
Owners sometimes cut construction administration to lower the fee, since AIA notes that CA services are rendered at the owner's discretion. The saving rarely holds. Without the architect reviewing submittals, product substitutions and field changes go through unchecked, and the drawings stop matching the building. If the budget is tight, reduce the number of site visits rather than removing CA altogether.
How Is the Architect's Fee Split Across the Phases?
The fee follows the workload, so construction documents and construction administration together usually carry the largest share. AIA itself does not publish a fixed percentage per phase; B101 leaves compensation for the parties to fill in. Public owners do publish their splits, and Washington State is one of the clearest examples.
In its 2027 to 2029 architect and engineer fee guidelines, Washington's Office of Financial Management divides the basic services fee for state projects as follows:
- Schematic design: 18%
- Design development: 20%
- Construction documents: 31%
- Bidding: 2%
- Construction contract administration: 27%
- Project closeout: 2%
Two details in that split are worth reading closely. First, construction administration (27%) sits only four points below construction documents, which reflects how much effort CA takes on a public project with formal submittal and payment procedures. Second, bidding gets just 2%, because the heavy lifting of a good bid happens in CD. Private practice splits vary by firm, building type and delivery method, but the overall shape, with documentation and site work outweighing early design, is consistent.
Fee percentages above come from one public owner's published schedule and are shown for reference. Your own split depends on the agreement you sign, so confirm the phase allocation in the contract rather than assuming a standard figure.
What Happens When the Phases Blur Together?
Real projects rarely move in clean steps. Fast-track schedules release a foundation package while the upper floors are still in DD. Design-build teams price the building while it is being drawn. BIM models carry DD-level information into SD because the software makes it easy. None of this is wrong, but it moves risk.
When phases overlap, decisions are fixed before the information behind them is complete. A foundation poured on DD-level loads may need strengthening when the final mechanical equipment turns out heavier. The practical response is to agree, in writing, which decisions each early package freezes, and to keep a log of assumptions that later phases must confirm. That log is often what separates a manageable change order from a dispute.
To see what drawings at each stage look like, our Architectural Revit Project Pack includes example schemes and project details.
Putting It All Together
Quick Recap:
- Pre-design defines the program, site and budget, and is often contracted separately from basic services.
- SD picks the scheme, DD makes every system fit it, and CD documents it for a contractor and a permit reviewer.
- Bidding or negotiation turns the CD set into a signed construction contract, and CA protects the design until the final certificate for payment.
- Washington State's published schedule gives CD 31% and CA 27% of the basic fee, so most of the effort comes after the design looks finished.
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