Design Development
Navigating Architecture's Most Detail-Critical Phase
Date
Apr 10, 2025
Reading Time
15 Minutes
Design Development (DD) marks a pivotal transition in the architectural process. While Schematic Design establishes what a building will be, Design Development determines precisely how it will come together. This third phase in the American Institute of Architects' design sequence transforms promising concepts into constructible solutions through rigorous technical development and interdisciplinary coordination.
At Solid Void, we view Design Development as architecture's moment of truth—where inspiring visions meet physical realities. During this phase, dimensions become exact, materials gain specificity, and building systems move from diagrammatic intent to coordinated solutions. It's where the architectural narrative established in Schematic Design acquires the technical vocabulary necessary for implementation.
For clients, Design Development represents a critical engagement period where decisions directly impact construction feasibility, long-term performance, and project economics. Understanding this phase helps clients participate strategically in the design process, making informed decisions while avoiding costly changes during construction.
Design Development transforms schematic concepts into technically coordinated building systems by refining spatial relationships, developing material specifications, integrating engineering disciplines, and establishing constructibility. This phase represents the transition from "design thinking" to "building thinking" as architectural concepts gain specific dimensions, detailing, and technical integrity. For clients, Design Development offers critical decision points impacting cost, performance, and aesthetics while preventing expensive construction-phase changes. Success requires disciplined system coordination, collaborative consultant management, and strategic client engagement focusing on value-driven options rather than overwhelming technical detail.
The Purpose and Scope of Design Development
Design Development serves several essential functions in the architectural process:
Refining spatial relationships with precise dimensions and clearances
Developing material selections and assemblies in detail
Coordinating architectural elements with structural, mechanical, and electrical systems
Resolving technical challenges identified during schematic design
Advancing regulatory compliance and code solutions
Finalizing performance specifications for building systems
Preparing for effective construction documentation
This phase typically advances the design to approximately 65-75% completion—sufficient detail to confirm constructibility and establish firm budget parameters while still allowing refinement during construction documentation.
Design Development focuses on resolving the "how" questions of architecture: How will this connection be detailed? How will these systems interact? How will these materials perform? The answers require both technical expertise and continued attention to the project's design intent, ensuring technical solutions support rather than compromise architectural objectives.
Key Components of Design Development
Architectural Refinement
While Schematic Design establishes general arrangements, Design Development requires precise spatial resolution:
Exact room dimensions and configurations
Wall thicknesses and construction types
Ceiling heights and soffit conditions
Door and window types, sizes, and operations
Millwork and built-in element design
Vertical circulation details
Interior partition layouts
Furniture planning and integration
For the Westlake Corporate Headquarters, schematic documents showed an open atrium connecting three floors with a monumental stair. During Design Development, this concept gained specific form: treads dimensions were established at 5'-6" width with 3/4" plate steel stringers supporting engineered wood treads. Glass guardrails were detailed with recessed base channels and minimal top connections to maintain visual lightness. The ceiling above received specific articulation with acoustic treatments integrated into lighting coves.
These refinements transformed an inspiring spatial concept into a precisely defined architectural element that could be accurately priced, engineered, and eventually constructed. The resulting feature perfectly expressed the client's desired workplace culture while meeting structural requirements and life safety codes.
Material Development and Specifications
Design Development establishes specific materials and assemblies through:
Exterior envelope system details
Interior finish selections and locations
Material transitions and intersections
Performance specifications for systems and components
Mock-ups and material testing as needed
Sustainability certification documentation
Maintenance and lifecycle considerations
The Riverview Community Center demonstrates this process in action. Schematic Design established a exterior concept using wood, glass, and stone to connect with the natural setting. During Design Development, these materials gained specificity: the "wood" became 1x6 clear western red cedar with semi-transparent stain in a rainscreen application; the "stone" became locally quarried granite in three specific finishes; the "glass" became thermally broken aluminum curtainwall with specific performance coatings and fritting patterns for solar control.
Beyond aesthetics, this material development included critical performance detailing: waterproofing connections, thermal break strategies, expansion joint locations, and maintenance access provisions. These technical aspects ensure the building will perform as intended throughout its lifespan while maintaining its architectural expression.
Building Systems Integration
Design Development coordinates architectural elements with engineering disciplines:
Structural system refinement and sizing
Mechanical system layout and distribution
Electrical system design and fixture selection
Plumbing fixture selection and distribution
Fire protection system integration
Telecommunications and low voltage systems
Building automation and controls
Energy modeling and performance verification
For Mason Memorial Hospital's new surgical center, this coordination proved particularly challenging. Advanced imaging equipment required specific structural vibration limits, while surgical suites needed precise temperature control and specialized air filtration. Ceiling spaces became increasingly crowded as these systems competed for space.
Through intensive coordination using 3D modeling, the design team identified conflicts early and developed strategic routing solutions. Key decisions included increasing floor-to-floor height by 16 inches to accommodate horizontal distribution zones and creating dedicated vertical shafts for each major system group. These fundamental coordination decisions during Design Development prevented costly conflicts during construction while enabling optimal performance for critical healthcare functions.
Regulatory Compliance Development
Design Development advances code compliance through:
Building and fire code analysis refinement
Accessibility compliance detailing
Health department and regulatory review preparation
Energy code documentation and compliance strategies
Zoning requirements verification
Special inspections identification
Permit submission preparation
For the Parkside Mixed-Use Development, Design Development revealed complex code interaction between the residential, retail, and parking components. Our code specialists worked closely with local authorities to develop specific occupancy separations, egress solutions, and fire protection approaches addressing these interactions. By resolving these issues during Design Development rather than during permitting, the project avoided several months of potential delay.
Cost Management and Value Engineering
Design Development provides increasingly accurate cost information through:
Detailed quantity takeoffs for major systems
Refined unit cost application
Market condition assessment
Constructibility review with cost implications
Value engineering option development
Cost-benefit analysis of system alternatives
Phasing and sequencing considerations
The Eastridge Office Campus demonstrates effective cost management during Design Development. When detailed curtainwall pricing exceeded budget allocations by approximately 22%, the team developed three alternative approaches with progressively reduced complexity and cost. Each option maintained the essential performance requirements while adjusting aesthetic expression.
Rather than simply presenting these as "good, better, best" options, our team provided detailed analysis of how each approach affected thermal performance, maintenance requirements, and visual quality. This information allowed the client to make an informed value decision rather than a purely economic one, ultimately selecting a middle option that preserved key design elements while bringing costs within budget parameters.
DD Process
System-by-System Development
Effective Design Development approaches building components systematically:
Establish control lines and key dimensions
Develop primary structural elements
Define envelope and exterior systems
Layout major mechanical and electrical distribution
Design vertical circulation and core elements
Detail typical conditions and repeated elements
Resolve special conditions and unique features
Coordinate systems at critical intersections
This sequential approach ensures fundamental systems receive appropriate attention before focusing on specialized conditions. It also facilitates coordination by establishing major systems before introducing more flexible elements.
Interdisciplinary Coordination
Design Development requires intensive collaboration across disciplines:
Regular coordination meetings with consultants
Clash detection through 3D modeling
Space allocation negotiations
Performance requirement verification
Design intent communication to technical specialists
Cross-disciplinary review and feedback
For the Westfield Sciences Building, weekly coordination sessions brought together architects, structural engineers, mechanical engineers, laboratory specialists, and sustainability consultants. These structured collaborations identified that fume hood exhaust requirements were driving mechanical system sizing, substantially increasing energy consumption. Through coordinated redesign of the laboratory layout and ventilation approach, the team reduced mechanical loads by 27% while maintaining research functionality.
Client Engagement and Decision Facilitation
Design Development generates numerous decisions requiring client input:
Material and finish selections
Equipment specifications
System performance requirements
Quality level determinations
Technical option evaluations
Cost-benefit assessment of alternatives
Effective client engagement during this phase requires:
Strategic information packaging
Clear cost and performance implications
Visual aids for technical concepts
Decision scheduling aligned with project timeline
Documentation of selections and approvals
At Solid Void, we've developed a tiered presentation approach for Design Development. Executive-level presentations focus on major decisions with significant cost or experiential impact. Operational reviews engage facility management teams with maintenance and performance considerations. Detailed technical reviews involve appropriate specialists in specific system decisions. This structured approach ensures the right stakeholders participate in relevant decisions without overwhelming anyone with unnecessary detail.
Documentation Development
Design Development produces significantly expanded documentation:
Dimensioned floor plans with all elements
Developed elevations with material indications
Building sections with assembly information
Wall sections and preliminary details
Reflected ceiling plans
Interior elevations of key spaces
System diagrams and distribution plans
Initial schedules for doors, windows, and finishes
Outline specifications
This documentation represents a substantial advance from schematic information. While Construction Documents will further detail these elements, Design Development documentation must be sufficient to confirm constructibility and establish accurate cost projections.
Common Design Development Challenges
Balancing Design Intent with Technical Requirements
As technical requirements emerge in greater detail, maintaining design intent becomes increasingly challenging. Ceiling heights are pressured by mechanical distribution, clean architectural detailing is complicated by waterproofing requirements, and material transitions must accommodate thermal movement and structural deflection.
For the Lakeside Concert Hall, acoustical requirements threatened the architectural concept of a "floating" wooden ceiling plane. Rather than abandoning the design intent, our team collaborated with acoustic consultants and structural engineers to develop a solution using perforated wood panels suspended below acoustically absorptive material. Custom edge detailing maintained the visual floating effect while concealing necessary technical elements. This approach preserved the essential design experience while meeting the demanding acoustic performance requirements.
Successful resolution of such conflicts requires:
Clear prioritization of design elements
Creative technical problem-solving
Understanding of performance requirements
Willingness to develop custom solutions
Effective cross-disciplinary communication
Managing Design Development Scope Creep
As details develop, clients often introduce new requirements or request changes to previously approved elements. Without proper management, these changes can cascade through interconnected systems, impacting budget and schedule.
The Hillcrest Corporate Headquarters project illustrates effective scope management. When the client requested a reconfiguration of the executive suite during late Design Development, our team immediately identified systems affected by this change: HVAC zoning, lighting controls, acoustic separation, and structural implications for a new internal stair.
Rather than proceeding immediately with design changes, we prepared an impact assessment documenting cost, schedule, and performance implications. This information allowed the client to make an informed decision about proceeding, ultimately choosing to maintain the original configuration after understanding the cascading effects of the proposed change.
Coordination Complexity
As project complexity increases, coordination challenges grow exponentially. Modern buildings contain numerous interrelated systems competing for limited physical space, particularly in ceiling and wall cavities.
The Memorial Hospital Surgical Pavilion exemplifies these challenges, with medical gas systems, advanced imaging equipment, specialized ventilation, and strict infection control requirements creating intense coordination demands. Our approach employed:
Early 3D modeling of all building systems
Regular coordination sessions with defined resolution protocols
Full-scale mockups of critical conditions
Clear space allocation hierarchies
Designated coordination leads for each discipline
This structured approach identified over 300 significant conflicts during Design Development rather than during construction, when resolution would have been substantially more expensive and disruptive.
Case Study: Design Development Transformation
Glendale Public Library Renovation
The Glendale Public Library project involved renovating a 1970s Brutalist structure to serve contemporary library functions. Schematic Design established an approach that preserved the concrete structural frame while creating a more transparent, welcoming environment through interior reorganization and strategic envelope modifications.
During Design Development, several significant challenges emerged:
The existing concrete structure contained unexpected reinforcement configurations that complicated new openings.
Original mechanical chases were insufficient for contemporary systems.
Floor-to-floor heights limited ceiling space for new distribution.
Energy code requirements demanded substantial envelope improvements.
Rather than compromising the design concept, the team developed innovative solutions:
For structural modifications, specialized scanning identified precise reinforcement locations, allowing carefully planned openings that worked with the existing structural logic. A custom concrete cutting sequence maintained structural integrity during construction.
For mechanical distribution, the team developed a raised access floor system in reading areas that served as an air plenum while providing flexibility for power and data. This approach eliminated most ceiling ductwork, preserving the exposed concrete ceiling as an architectural feature.
For energy performance, the team designed a custom interior insulation system for concrete walls that preserved exterior appearance while significantly improving thermal performance. Computational fluid dynamics modeling verified that the natural ventilation strategy would perform as intended with the modified envelope.
These technical solutions—all developed during Design Development—preserved the architectural concept while resolving complex constraints. The resulting building maintained its powerful concrete expression while functioning as a high-performance contemporary library. Energy use decreased by 62% compared to pre-renovation performance, and visitation increased by 37% in the first year after reopening.
This outcome demonstrates how effective Design Development transforms promising concepts into constructible, high-performance architectural solutions without compromising design integrity.
Client Engagement During Design Development
Understanding Client Roles in Design Development
Design Development requires specific client involvement:
Executive Decision-Makers: Focus on major system selections, significant cost implications, and key performance standards.
Facilities Management: Provide input on maintenance requirements, operational preferences, and long-term durability considerations.
End-User Representatives: Evaluate functional layouts, equipment integration, and operational workflows.
Project Management Team: Coordinate decision timing, budget alignment, and schedule implications.
For institutional clients like universities or healthcare organizations, we establish structured engagement protocols with clear responsibilities for each stakeholder group. This prevents decision paralysis while ensuring appropriate input at each development stage.
Effective Communication Strategies
Technical information must be presented appropriately for different audiences:
Visual Communication: Use diagrams, renderings, and simplified graphics to explain complex systems.
Mock-ups and Samples: Provide physical examples of key materials and assemblies.
Comparative Analysis: Present options with clear metrics rather than overwhelming technical detail.
Decision Documentation: Record selections with supporting rationale for future reference.
For the Westside Corporate Campus, we created a tiered presentation strategy with executive summaries, department-specific packages, and technical appendices. This approach allowed stakeholders to focus on relevant information while maintaining comprehensive documentation.
Strategic Decision Scheduling
Design Development requires numerous decisions with complex interdependencies. At Solid Void, we develop client-specific decision schedules that:
Identify all required client decisions
Establish necessary sequence based on technical dependencies
Allocate appropriate review time for each decision type
Communicate impacts of delayed decisions
Document decision outcomes and implications
This structured approach prevents cascading delays while ensuring clients have appropriate information for each decision point.
From Design Development to Construction Documents
Successful Design Development creates the foundation for efficient Construction Documents through:
Resolved technical approaches for all major systems
Established material selections and specifications
Coordinated interdisciplinary systems
Verified code compliance strategies
Refined cost models aligned with budget parameters
For the Clearwater Office Tower, Design Development concluded with a comprehensive system coordination report identifying specifically how each building system would interact with others. This documentation ensured the subsequent Construction Document phase could focus on detailing and specification refinement rather than fundamental system resolution.
Conclusion
Design Development represents architecture's technical coming-of-age—where inspiring concepts develop the specific attributes necessary for construction. While less visually dramatic than Schematic Design, this phase has profound impact on project success, determining whether architectural intentions will translate faithfully into built reality.
At Solid Void, we view Design Development as a crucial investment in project quality and risk reduction. The rigorous technical work performed during this phase prevents costly surprises during construction while ensuring buildings perform as intended throughout their lifecycle.
For clients, effective engagement during Design Development offers opportunities to influence critical aspects of building performance, maintenance requirements, and long-term operational costs. Understanding this phase helps clients participate strategically in the design process, making informed decisions while avoiding disruptive late-stage changes.
As architectural projects grow increasingly complex with advanced systems and performance requirements, the importance of thorough Design Development continues to increase. The most successful projects invest appropriate resources in this critical phase, recognizing that technical excellence is essential to architectural achievement.
This article is the third in Solid Void's six-part series exploring the AIA design phases. Our previous installments examined Pre-Concept Design and Schematic Design, and our next will explore Construction Documents—the phase where design development decisions are translated into comprehensive instructions for builders.