The schematic design phase
Schematic design is where program becomes form. You take the approved brief from the programming phase and produce a concept the client can visualise, react to, and ultimately sign off on. The product is not a set of construction documents: it is a set of decisions that define the building's fundamental character.
Decisions made at the schematic stage are the most consequential in the project. Studies of project cost show that roughly 70 percent of the final project cost is committed by the end of schematic design, when total fees spent are typically less than 15 percent of the budget. Changing the structural system or the massing at design development costs far more than changing it now.
| Phase | Key output | Cost committed |
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| Programming | Approved architectural program | ~5% |
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| Schematic Design | Client-approved concept package | ~70% |
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| Design Development | Coordinated DD drawings | ~85% |
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| Construction Documents | Permit-ready drawing set | ~95% |
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| Construction Administration | Completed building | 100% |
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Examitect's ExAC study plan addresses Schematic Design in one sub-category. Click the jump button below to go directly to the sub-category notes.
What enters and exits the schematic design phase
Understanding the phase boundary is itself an ExAC topic. Questions often ask what the architect needs before starting SD, what decisions get made during it, and what the client must approve before DD begins.
| SD inputs | Source |
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| Signed-off architectural program | Programming phase; client-approved |
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| Signed professional services agreement | Owner; required before design work begins |
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| Site survey and legal description | Surveyor; defines property lines, easements, setbacks |
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| Geotechnical report | Geotechnical engineer; defines soil bearing and foundation options |
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| Zoning and planning review | Municipality; confirms permitted use, height, density |
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| Utility servicing information | Utility companies; water, sewer, electrical capacity |
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| SD vs. DD: what gets decided where | SD | DD |
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| Massing and building footprint | Established | Refined |
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| Structural system family | Selected | Sized and specified |
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| Core and circulation layout | Located | Dimensioned |
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| HVAC system type | Chosen | Designed |
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| Exterior envelope material | Not yet selected | Selected and specified |
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| Door and hardware schedules | Not applicable | Produced |
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| Cost estimate | Class C or D (elemental) | Class B (detailed elemental) |
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Exam tip
If a question asks whether an action is appropriate "at the schematic stage," check whether it involves setting the concept or refining the details. Concept-setting belongs in SD; detail refinement belongs in DD. Selecting a specific exterior cladding material, for example, is a DD decision, not an SD decision.
6.1 Understand aspects of schematic design
This sub-category covers the full arc of the schematic phase, from the first site visit through to the client-approved SD package. It is the only sub-category for Schematic Design in Examitect's ExAC study plan, so all questions in this topic map back to one or more of the six aspects below.
| Aspect | What it involves | Key reference |
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| Site conditions | Reading topography, solar angles, wind, views, legal constraints, and servicing to generate concept opportunities and constraints | CHING 1.13-1.44 |
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| Concept and massing | Developing the parti, testing organisation patterns against the program, and producing massing options the client can compare | CHING 2.02-2.40; CHOP Ch. 6.2 |
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| Structural system selection | Choosing a structural system family based on program bay requirements, floor-to-floor targets, and budget; using span rules of thumb to confirm feasibility | Studio Companion Sec. 1-2 |
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| Environmental design | Applying passive strategies (orientation, shading, thermal mass, natural ventilation) and sizing major glazing areas for daylighting | HCL Ch. 1, 19; Studio Companion Sec. 3 |
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| Engineering coordination | Directing consultants to confirm system types, locate shafts and equipment rooms, and confirm service capacities before SD submission | CHOP Ch. 6.2; Studio Companion Sec. 4 |
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| SD deliverables | Producing the drawing set, outline specification, preliminary code analysis, and Class C or D cost estimate; presenting to the client and obtaining sign-off to proceed to DD | CHOP Ch. 6.2 |
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Site analysis at the schematic stage
CHING pages 1.13 to 1.44 cover the information an architect reads from a site and how each factor shapes early design decisions. At the schematic stage you are not just documenting site data: you are translating it into constraints the concept must respect and opportunities the concept should exploit.
| Site factor | Data source | Design implication |
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| Solar angles | Sun-path diagram (latitude-specific) | Orient the long building axis east-west; shade south-facing glazing with horizontal overhangs; limit west-facing glass to control afternoon heat gain |
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| Prevailing winds | Climate data, wind rose | Locate operable windows on the leeward face for natural ventilation; position mechanical intakes upwind of exhaust outlets |
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| Topography and drainage | Site survey, contours | Set finished floor elevations above the 100-year flood plain; use grade changes to introduce daylight to lower levels |
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| Views and privacy | Site visit, photographs | Maximise valued views; screen service areas and loading from public streets and neighbouring residential uses |
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| Setbacks and easements | Site plan, title search, zoning by-law | All buildings, overhangs, and below-grade structures must clear setback lines and easement corridors |
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| Soil bearing capacity | Geotechnical report | Determines foundation type: spread footings (good bearing), mat (poor or variable), piles (soft or contaminated soils) |
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| Existing vegetation | Arborist report, survey | Identify trees to protect under municipal by-law; factor existing canopy into summer shading analysis |
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| Access and servicing | Site plan, municipal drawings | Confirm pedestrian, vehicle, and emergency access points; locate service entry away from primary facades |
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Exam tip
ExAC questions on site analysis often present a scenario with a specific site constraint and ask what design response is most appropriate. The correct answer addresses the constraint directly (e.g., orienting the building, adding shading) rather than ignoring it or pushing it to a later phase. Reading CHING 1.13-1.44 carefully before the exam pays off here.
Building organisation patterns
The primary spatial organisation patterns that architects use to translate a program into a plan are catalogued in Ching's Architecture: Form, Space, and Order; the CHING primary reference, Building Construction Illustrated pages 2.02 to 2.40, complements them with whole-building systems and structural concepts. Each pattern has a characteristic form, a characteristic circulation system, and a set of program types for which it performs well. Choosing the right organisation pattern is one of the first concept decisions you make in SD.
| Organisation pattern | Form description | Well-suited programs |
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| Centralised | A dominant central space surrounded by secondary spaces oriented toward it | Civic buildings, libraries, museums, atria |
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| Linear | Spaces arranged along a primary circulation spine; the spine can be straight, bent, or curved | Schools, hospitals, residential corridors, long-span industrial |
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| Radial | Linear wings radiating from a central node; combines centralised and linear characteristics | Airports, some hospitals, prisons (surveillance from centre) |
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| Clustered | Spaces grouped by functional proximity without a strict geometric order; linked by adjacency rather than a spine | Village-scale plans, campus planning, childcare centres |
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| Grid | Spaces arranged on a regular structural grid; allows flexibility and future reconfiguration | Office buildings, laboratories, research facilities, retail |
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The building organisation pattern you select must be consistent with the approved program. A hospital program with many identical patient rooms points toward a linear or grid organisation; a civic building program centred on a large public hall points toward a centralised organisation. ExAC questions sometimes present a program and ask you to identify the most appropriate organisation type, or present a massing and ask whether it is consistent with a given program.
Exam tip
A parti is a specific expression of the organisation pattern: it is the single governing concept that unifies the building. The parti should be expressible as a simple diagram. Questions about parti ask whether proposed changes are consistent with it, not whether the building looks a certain way.
Structural system selection
At the schematic stage you select a structural system family based on three inputs: the bay spans required by the program, the floor-to-floor heights required by the mechanical and occupancy type, and the cost target. You are not yet sizing members or specifying connections: that is design development work. Use the span rules of thumb below to confirm feasibility and eliminate incompatible systems.
| Structural system | Typical bay span | Floor-to-floor | Common uses |
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| Light wood frame | 3 to 6 m | 2.7 to 3.0 m | Houses, low-rise multi-family, small commercial |
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| Post-and-beam wood | 6 to 9 m | 3.0 to 4.0 m | Small commercial, community halls, barns |
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| Mass timber (CLT / glulam) | 6 to 12 m | 3.5 to 4.5 m | Mid-rise residential, institutional, office |
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| Steel open-web joists | 9 to 18 m | 3.5 to 4.5 m | Schools, retail, light industrial, arenas |
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| Steel wide-flange frame | 9 m or more | 3.5 to 5.0 m | Office towers, institutional, mixed-use high-rise |
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| Concrete flat plate | 6 to 9 m | 3.0 to 3.5 m | Residential, hotel (no drop panels) |
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| Concrete flat slab | 8 to 12 m | 3.5 to 4.5 m | Parking structures, commercial (with drop panels) |
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| Concrete waffle slab | 9 to 15 m | 4.0 to 5.0 m | Auditoriums, laboratories, long-span institutional |
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Exam tip
ExAC questions on structural systems often give you a program with a specific bay requirement (e.g., 12 m column-free spans for a gymnasium) and ask which system is most appropriate. Match the required span to the table above and eliminate systems that cannot reach it. Then consider cost: wood is generally least expensive, post-tensioned concrete and steel wide-flange are more costly. The right answer usually satisfies both span and cost constraints.
Passive design strategies at the schematic stage
Heating, Cooling, Lighting Chapters 1 and 19 cover the climate-responsive design principles and daylighting rules of thumb that apply at the schematic stage. You are not running energy models: you are making concept decisions that determine whether the building will perform well or poorly before mechanical systems are even selected.
| Passive strategy | SD decision | Reference |
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| Solar orientation | Align the long building axis within 15 to 20 degrees of true east-west to maximise south exposure for heating and minimise east and west exposure for cooling | HCL Ch. 1 |
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| Shading | Provide horizontal overhangs on south glazing sized to block high summer sun and admit low winter sun; use vertical fins on east and west facades | HCL Ch. 1 |
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| Thermal mass | In heating climates, use exposed concrete or masonry on interior south-facing surfaces to store solar gain and release it overnight | HCL Ch. 1 |
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| Natural ventilation | Locate operable openings on opposite facades to create cross-ventilation; use stack-effect strategies (atria, clerestories) to draw air through deep plans | HCL Ch. 1 |
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| Daylighting | Target a window-to-floor-area ratio of 20 to 30 percent for well-daylit offices; place windows high in the wall to distribute light deeper into the floor plate; use light shelves to redirect light to the ceiling | HCL Ch. 19 |
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| Glare control | Avoid placing workstations directly facing west windows; use external shading or fritted glazing on high-glare orientations | HCL Ch. 19 |
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Exam tip
Questions about passive design at the schematic stage ask what the architect should decide now, not what the mechanical engineer will size later. If a question asks about cooling load reduction at the SD stage, the correct answers involve orientation, shading, and window-to-wall ratio, not cooling system selection or duct sizing.
Engineering consultant coordination
The architect does not produce all of the schematic design package alone. During SD you direct each engineering consultant to produce a preliminary input that you incorporate into the SD submission. The goal is to confirm that the concept is structurally feasible, that the mechanical and electrical systems fit within the floor-to-floor heights and core locations you have proposed, and that utility service capacities are adequate.
| Discipline | SD deliverable | Key question for the architect |
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| Structural | Preliminary structural concept note; typical bay sketch showing system type, approximate depth, and column grid | Does the proposed structural grid support the program bay sizes and fit within the target floor-to-floor height? |
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| Mechanical (HVAC) | System type recommendation; approximate shaft and mechanical room locations; preliminary ventilation and cooling load estimate | Have central shafts and penthouse or basement mechanical room locations been confirmed and reflected in the plans? |
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| Plumbing | Core location confirmation; preliminary wet area stacking diagram; pipe route from each floor to the building drain | Are all wet areas stacked vertically above a clear basement pipe route to the municipal sewer? |
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| Electrical | Service entry point; approximate main switchgear room location; preliminary load estimate | Has utility service capacity been confirmed for the project's estimated electrical load? |
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| Fire protection | Sprinkler and standpipe system type recommendation; preliminary water supply confirmation | Does the structural bay spacing allow standard sprinkler head coverage without additional intermediate supports? |
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Exam tip
ExAC questions sometimes describe a situation where a consultant has not yet confirmed a key input and ask what the architect should do. The correct answer is to obtain the confirmation before finalising the SD submission, not to proceed without it. An SD package submitted without confirmed shaft locations or structural feasibility is incomplete.
The schematic design deliverable set
CHOP Chapter 6.2 describes what the SD package contains. The drawing set is produced at a low level of detail: the goal is to communicate the concept clearly enough for the client to make an informed approval decision, not to provide information for construction.
| Document | Typical scale | Content |
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| Site plan | 1:500 | Building footprint, setback compliance, vehicular and pedestrian access, grading concept, landscaping zones |
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| Schematic floor plans | 1:200 | Room layout, circulation paths, core location, structural grid, gross floor area by use |
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| Building sections | 1:200 | Floor-to-floor heights, structural system depth, roof profile, relationship to grade |
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| Preliminary elevations | 1:200 | Massing, window proportions, main entry, relationship to adjacent buildings |
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| Outline specification | Text | Structural system family, exterior cladding material families, mechanical system type, sustainability targets |
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| Preliminary code analysis | Text | Occupancy group(s), construction type, allowable height and area, exit count and locations, accessible routes |
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| Preliminary cost estimate | Text | Class C or D elemental estimate; plus or minus 15 to 25 percent accuracy; total project cost and cost per gross square metre |
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Code analysis at the schematic stage
The preliminary code analysis is not the full code review you will complete at DD: it is a strategic check to confirm the concept is viable under the National Building Code. At minimum you confirm:
- Major occupancy group and any secondary occupancies
- Construction type (combustible vs. non-combustible) and whether it is consistent with the building height
- Number of storeys and whether the building exceeds the limits for the proposed construction type
- Minimum number of exits and whether the floor plate configuration can accommodate them
- Whether accessible path of travel is feasible from the site to all major spaces
Preliminary cost estimation
The cost estimate is one of the most consistently tested topics in Schematic Design questions. At SD you produce a Class C or D estimate to confirm the concept is feasible within the client's budget. If the estimate exceeds the budget, you adjust the concept now, when changes are inexpensive, rather than at DD or CD stage.
| Estimate class | Accuracy | Basis | Used when |
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| D (Conceptual) | ±25 to 40% | Total cost per gross square metre of building type | Feasibility study; programming phase budget confirmation |
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| C (Schematic) | ±15 to 25% | Elemental cost per square metre by building element (structure, envelope, interiors, mechanical, electrical, sitework) | SD approval; client budget confirmation before DD begins |
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| B (Design development) | ±10 to 15% | Detailed elemental with quantities and unit prices | DD approval; financing applications |
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| A (Tender) | ±5 to 10% | Unit prices from trade breakdowns; contractor-confirmed | Tender and contract award |
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Elemental cost format
A Class C estimate breaks the project cost into major elements rather than trade divisions. Common elements include: substructure (foundations), structure (floor and roof systems), exterior enclosure (walls, windows, roof membrane), interior construction (partitions, finishes, doors), mechanical systems, electrical systems, and site works. Each element is estimated as a cost per square metre of building area multiplied by the gross floor area. This elemental structure follows the Uniformat II classification summarised in CHING Appendix A.23.
Exam tip
RSMeans and Yardsticks for Costing are the primary Canadian sources for unit cost data. Both are open-book references on the ExAC. Questions about cost estimation at SD ask about the process and the appropriate accuracy range, not about memorising specific dollar values.
Key terms and reference guide
The glossary below covers the terms most often tested in Schematic Design questions. The reference guide that follows tells you which source to consult for each type of question.
- Parti
- The single governing concept from which all major design decisions flow; expressible as a simple diagram; the "big idea" of the project.
- Schematic design
- The project phase in which the approved program is translated into a concept: massing, organisation, structural system, and a cost estimate the client can approve.
- Design development
- The phase following SD in which the approved concept is refined: materials are selected, dimensions are fixed, and engineering systems are designed in detail.
- Elemental estimate
- A cost estimate that organises project costs by building element (structure, envelope, mechanical, etc.) rather than by trade or specification division.
- Class C estimate
- An elemental estimate with accuracy of plus or minus 15 to 25 percent; the standard format for cost confirmation at the SD stage.
- Organisation pattern
- The spatial strategy that relates rooms and spaces to each other: centralised, linear, radial, clustered, or grid.
- Structural grid
- The regular layout of columns or bearing walls that defines the structural bays; established at SD, refined at DD.
- Bay span
- The centre-to-centre distance between columns or bearing walls in one direction; the primary driver of structural system selection.
- Floor-to-floor height
- The distance from finished floor to finished floor on the storey above; must accommodate structural depth, mechanical zone, and occupied ceiling height.
- Passive design
- Building design strategies that reduce energy demand without mechanical intervention: orientation, shading, thermal mass, natural ventilation, and daylighting.
| Question type | Primary reference | Pages or sections |
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| Site analysis and constraints | CHING | 1.13-1.44 |
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| Building organisation and massing | CHING | 2.02-2.40 |
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| Structural system selection | Studio Companion | Sec. 1-2 |
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| SD process and deliverables | CHOP | Ch. 6.2 |
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| Passive design and solar strategy | HCL | Ch. 1 |
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| Daylighting | HCL | Ch. 19 |
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| Mechanical system type selection | Studio Companion | Sec. 3-4 |
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| Cost estimation method and accuracy | CHING; RSMeans; Yardsticks for Costing | App. A.23 (Uniformat II); Introduction sections |
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ExAC question patterns and strategies
Schematic Design questions follow recognisable patterns. Knowing the patterns helps you identify the correct answer quickly and avoid the distractors the examiners build in.
Common question types
- Phase boundary questions. A scenario describes an action and asks whether it is appropriate "at the schematic stage." Check whether the action involves concept-setting (SD) or detail refinement (DD).
- Structural system selection. A program gives you required bay spans and asks which system is most appropriate. Match span to the table in Card 7; eliminate systems that cannot reach the required span.
- Site constraint response. A site condition is described (steep grade, prevailing wind, south-facing adjacent building) and the question asks what design response is most appropriate at SD.
- Deliverable identification. A question asks what document belongs in the SD submission. Know the seven items in the SD deliverable set from Card 10.
- Cost estimate accuracy. A question asks which estimate class is appropriate at a given project stage, or what the accuracy range of a Class C estimate is.
- Engineering input timing. A question asks when a specific consultant input is required. Structural feasibility, shaft locations, and utility capacity confirmations all belong in the SD phase.
Common distractors
- Answers that push SD decisions into DD (e.g., "defer structural system selection until DD") are almost always wrong; the structural system must be confirmed at SD.
- Answers that push DD details into SD (e.g., "select the exterior cladding material") are also wrong; material selection belongs in DD.
- Cost estimate answers that overstate accuracy (e.g., "plus or minus 5 percent") are wrong for the SD stage; plus or minus 15 to 25 percent is correct for a Class C estimate.
- Passive design answers that require mechanical intervention are wrong when the question asks about passive strategies specifically.
Exam tip
The single most effective strategy for SD questions is to ask: is this a concept decision or a detail decision? If it is a concept decision and the question is set at the SD stage, the action is appropriate. If it is a detail decision, it belongs in DD. This filter eliminates the majority of distractors.