Chapter 6.3
Design Development



During the design development phase, the selected scheme, which was prepared during the schematic design phase, is refined and developed in more detail. See Chapter 6.2 – Schematic Design for a discussion of that initial phase of design. Whereas the schematic design generally describes “what” is being built, the design development phase explores and determines “how” it is being built and how it will operate, with design features of the project more fully developed.

The building information modeling (BIM) process and the need for detailed technical analysis brought on by the integrated design process (IDP) and integrated project delivery (IPD) have changed the division of effort and scope of deliverables in the early phases of the design project. BIM and complying with the energy code often necessitate that work traditionally associated with design development is moved to schematic design. Design projects are becoming “front-end loaded.” Design decisions are required earlier in the process, and a redistribution of effort and associated fees results in more work during schematic design and design development and less during contract document production. In most jurisdictions, design development generally aligns with the obtaining of planning approvals from the authorities, while sealed construction documents, or a portion thereof, are necessary to acquire construction permits.

It is sometimes difficult to differentiate between when the schematic design phase ends and when the design development phase begins; more so when a full BIM process is being used. Some architects and most engineers combine these two early phases into a single phase, termed “preliminary design.” Although the conflation of phases may reflect the actual design process that takes place within an office, the architect needs to manage client and stakeholder engagement through patterns of work, evaluation, decisions and more work. To promote a professional client-architect relationship, firms should develop a statement of work for each phase of the design project with clearly defined deliverables that can be validated. It is strategic to obtain initial approval of the early concept from the client before proceeding to more specific design details.

The term design has different meanings depending on the context of use and who is using it. Engineers and some clients frequently use the term “design” to refer to construction documents as well as preliminary design. In the way architects use the term, it refers to the professional work associated with graphic or 3-D representations of the building project. It is important to have a mutual understanding of each phase, and to plan for the appropriate documentation when communicating with engineers.

Once the design is developed and accepted by the client, the project can move into the next phase – construction documentation. See Chapter 6.4 – Construction Documents – Drawings and Specifications for this stage of a project.

This chapter briefly describes the services of the architect during the design development phase of a project.

Design Development Tasks

The various alternative Schedules of Architect’s Services and Client Responsibilities to be attached to the Canadian Standard Form of Contract for Architectural Services RAIC Document Six outline some of the architect’s responsibilities during design development. During this phase, refining the design usually entails the following tasks:

  • preparation and coordination of all architectural, structural, mechanical and electrical designs;
  • preparation of outline specifications;
  • performing preliminary modelling and simulations (such as energy analysis and daylight simulation) if included in the architect’s services;
  • developing construction phasing and occupant decanting scenarios if included in architect’s services;
  • development of a regulatory compliance strategy including reviews with authorities having jurisdiction to test the assumptions made in schematic design and to make any adjustments;
  • preparation of presentation documentation (such as drawings, models, computer renderings, as agreed to in the client-architect agreement);
  • update of the construction cost estimate;
  • update of the schedules for design, preparation of construction documents, and time frame (schedule) for construction.

During the design development phase, it is critical to resolve the design of all major building components and the spaces needed to properly house the mechanical and electrical systems. At this stage, the input and collaboration of the consultant team is essential to the success of the project. The activities of coordination do not begin just as contract document product approaches completion, but throughout the entire design process. A well-integrated design will minimize delays resulting from coordination challenges during construction documents production. Any significant revisions during the later stages will be costly to the client, the architect and subconsultants, and can result in compromises to the building design concept.

During design development, the client is responsible for the following:

  • reviewing and commenting on the design;
  • providing written approval of the design and authorizing the preparation of construction documents.

One of the roles for the architect during design development is to investigate various construction materials, products, systems, and manufactured products for incorporation into the future building. In some cases, the previously developed functional program may have outlined the requirements for durability and maintenance of certain finishes, furnishings, and equipment. During design development, the architect should assess the specifications of various materials as well as their cost and performance to determine if they meet the client’s needs, as stated earlier in the pre-design and schematic design phases.

Prior to making a final recommendation to the client, the architect should review the following factors:

  • availability of the product or system from the manufacturer or supplier as well as the types/durations of warranties available;
  • available technical data, samples and literature on the product;
  • performance criteria (including sustainability, durability, suitability for application and compatibility with other materials);
  • maintenance requirements;
  • physical characteristics and availability of various colours, finishes, textures or other features;
  • fabrication and installation requirements;
  • capital cost;
  • operating cost projections;
  • construction phasing and schedule implications;
  • past performance;
  • comparative analysis with similar products in the marketplace;
  • requirements and products to meet accessibility or sustainable “green” building initiatives.

Engineering Services for Design Development

As previously indicated, continuing to coordinate the design work at this stage with all engineering disciplines is critical to the success of the project. Collaboration with the engineers should begin in the schematic design phase of the project and continue with greater intensity during design development.


During the schematic design stage, the structural engineer may have developed alternative framing plans which indicate basic elements, such as typical bays and their spacing together with their associated costs. The structural engineer may analyze various framing systems such as concrete, steel and timber. Due to changes in supply or market prices that may have occurred since schematic design, some earlier decisions may need to be revisited. At this stage, an economical and functional framing system and appropriate bay size should be selected; however, the architect and engineer must also account for several other considerations, such as availability of the material and appearance of the system. This decision is frequently dictated by those functional or aesthetic considerations.

Subsequently, to commence design development, the architect should provide the structural engineer with the following information:

  • the soils or geotechnical report (usually prepared at pre-design stage and supplied by the client but may need further investigations based on the final form and location of the building);
  • the selected schematic design and any accompanying reports;
  • known restrictions regarding the locations of columns or other structural supports;
  • defined areas, including use, size and finishes;
  • preliminary code analysis including fire separations and fire ratings;
  • the size and locations of openings;
  • construction materials;
  • a confirmation of the method of construction project delivery and the expected time frame which was selected by the client in the schematic design phase.

Some of the design issues which must be resolved with the structural engineer and the members of the design team through an integrated design process include:

  • typical bay framing, including typical sizes of beams and columns;
  • maximum depths of members and all critical sizes of members;
  • size and location of openings through the structure for all work by other disciplines;
  • minimum ceiling clearances to the underside of the structure and all floor to floor heights;
  • identification of items to be embedded into the structure;
  • requirements regarding fire ratings and fire separations;
  • any special local seismic or wind-loading considerations;
  • determination of potential for radon gas infiltration under the slab;
  • provisions for special equipment and typical mechanical equipment, including window washing equipment, mechanical rooftop units, self-leveling docks, chimneys, slab depressions, fall-arrest anchors, snow loading, etc.


The client’s requirements for operation and maintenance (for example, regulations pertaining to stationary engineers) and the requirement for emergency standby and dual-equipment systems may have been included in the functional program. If these were not part of the program, the architect should assist the engineers in determining the client’s needs and ascertain if the mechanical design meets them.

To undertake design development, the mechanical engineer will require various types of information, including:

  • the selected schematic design;
  • operating cost projections, particularly energy use analysis and benchmarks;
  • type of glazing and window coverings along with their energy characteristics;
  • hours of occupancy of the building;
  • allowable variation in room temperatures and humidity;
  • areas requiring special treatment for air conditioning, fire protection, plumbing, noise;
  • preliminary code analysis, including building classification and required fire separations;
  • requirements for mechanical system controls and special controls and energy management;
  • analysis of special water quality parameters and special waste removal equipment;
  • other special equipment, such as lawn or green roof irrigation systems.

The architect or the client may provide some of this information, or the mechanical engineer will obtain some of the information directly from the appropriate authorities.

During the design development phase, the mechanical engineer selects equipment for and resolves:

  • natural ventilation;
  • central versus individual heating and cooling plants;
  • size of air conditioning equipment;
  • size of heating system;
  • special HVAC systems such as heat recovery systems, heat pumps;
  • energy analysis and modelling, if part of the agreed-upon professional services;
  • approximate size and location of major ducts and pipes;
  • approximate size of all mechanical equipment and the service room area/volumes to house them;
  • plumbing fixtures and controls;
  • other features, such as noise control, vibration dampers, fire dampers, special controls, etc.;
  • location, geometry and dimensions of main mechanical systems rooms and ancillary or support spaces;
  • location, path and rough dimensioning of all main vertical shafts and horizontal ducts for plumbing, fire protection and HVAC (separately or in combination);
  • coordination with electrical and sprinkler disciplines to identify potential locations where pipes, wiring, ducts and other systems may clash;
  • identification of potential constructability concerns, such as crane locations for installing large mechanical elements;
  • examination of the existing sanitary services for capacity now that the number of fixtures and water usage can be predicted;
  • coordination with the electrical design to locate and quantify any exceptional power needs of proposed mechanical equipment;
  • high-level clash detection;
  • location, path and rough dimensioning of all main vertical shafts and horizontal ducts for plumbing, fire protection and HVAC (respectively or in combination).

With increased building performance requirements, energy modelling has become a common addition to the scope of design work. In addition to preparing a set of design development drawings, the mechanical engineer or energy specialist may prepare projections on energy costs for the proposed building. This information builds on any estimates prepared during pre-design and should provide the operating costs of mechanical equipment as affected by various options of building materials and envelopes. In cases where the integrated design process (IDP) is used as the basis for the design process, the architect is the leader of the integrated design team. In all instances, the architect coordinates the activities of the engineering disciplines to ensure that the design evolves collaboratively, with each discipline aware of and responding to the design of the other team members. A shared building model and file-sharing capabilities can aid coordination, promote integration, and curtail siloed thinking where individual disciplines work in isolation.


To carry out the design development documents, the electrical engineer requires the following information:

  • the selected schematic design and accompanying reports;
  • information on typical areas, including function, size, finish and materials, lighting levels;
  • the future expansion and flexibility required for each space;
  • location and power-consumption characteristics of major mechanical equipment;
  • the method of construction project delivery and expected time frame.

During the design development phase, the electrical engineer resolves the following design issues related to the electrical systems:

  • the anticipated electrical load and allowances for future expansion;
  • requirements of incoming electrical services and any space requirements for a vault or sub-station;
  • the distribution of power and utilization voltages;
  • locations and area/volume of electrical closets, communications rooms, bus duct risers, etc.;
  • requirements for embedding conduits;
  • location and preliminary sizing of main vertical and horizontal structured cabling infrastructures;
  • light fixture selection (exterior and interior) and requirements for ceiling systems and ceiling space;
  • coordination of mechanical on switching and controls for energy efficiency;
  • telecommunications and data systems, fire alarm systems, public address systems, intercom, security.

For the lighting design, the architect works with the electrical engineer to develop lighting layouts. These layouts are often developed with the use of the architectural reflected ceiling plans with input from the electrical engineer or a specialist lighting consultant. Careful consideration should be given to the types of lighting as each has implications for energy-use, replacement, and long-term operational costs.

Municipal Services and Site Systems

To carry out the design development documents, the civil or site servicing engineer requires the following information:

  • the soils or geotechnical report (usually prepared at the pre-design stage and supplied by the client but may need further investigations based on the final form and location of the building);
  • the selected schematic design and accompanying reports;
  • occupant loading;
  • capacity of the municipal services supplied to the site, such as:
    • available electrical power;
    • potable water for occupant use, building systems and fire suppression;
    • storm water discharge systems;
    • sanitary sewer;
  • municipal construction projects planned for adjacent properties, including roads and sidewalks;
  • locations of non-municipal services such as telephone and data service lines;
  • soil characteristics to absorb storm water;
  • topographic and legal land surveys;
  • below-grade services locations;
  • known restrictions regarding setbacks, storm water management and utility corridors;
  • sustainable and regenerative design strategies.

During the design development phase, the civil engineer resolves the following design issues related to site servicing systems:

  • locations of below-grade services connecting to municipal services;
  • upgrading requirements of municipal services to address capacity issues;
  • approximate site grading and surface water management strategy;
  • site power distribution (in collaboration with electrical engineer);
  • vehicular, pedestrian and cyclist traffic patterns into and around the site (in collaboration with the architect and landscape architect).

Landscape Architecture

Landscape architects integrate and apply knowledge of ecology, socio-cultural factors, economics, and aesthetics to create outdoor (and sometimes indoor) environments that are functional, innovative, appropriate and attractive. This work effectively integrates with the architect’s design, and serves to both complete and strengthen the overall architectural solution.

During the schematic design stage, where the scope of the architect’s work involves designing the open space surrounding the building(s), a landscape architect is most often involved in providing some conceptual thoughts about the hard and soft landscaping aspects of the project, including landscape design, site planning, storm water management, erosion control and environmental restoration. Landscape concept plans are sometimes (but not always) prepared as part of the schematic design presentation or submission to the client.

To carry out the design development documents, the landscape architect requires the following information:

  • the selected schematic design at both the building(s) and site levels;
  • a thorough briefing of the architectural design approach to the building(s) and thoughts from the architect on the overall operational and aesthetic goals for the project;
  • site above-ground and below-ground utilities locations;
  • pedestrian and vehicular access points into the building(s) including main and secondary entrances, fire exits, loading bays, service bays, vehicular circulation and parking requirements, and other site circulation information critical to project operations;
  • viewing cones, privacy needs, and other information regarding visual impact from spaces internal to the building(s) and from external positions looking towards the building(s);
  • programmatic requirements for urban design elements such as bicycle racks, benches, gathering spaces, etc.;
  • specialized items such as sculptures, monuments, gazeboes, screens, decorative walls, etc.;
  • site lighting requirements;
  • other programmatic or site requirements requested by the client or required by jurisdictional authorities.

At this stage, the landscape architect will prepare, in close collaboration with the architect, drawings such as:

  • site plans indicating vehicular and pedestrian pathways;
  • the layout of hard surfaces and structures defining dimensions and materials to be used;
  • layout of planting areas identifying names and locations for all proposed, existing and transplanted plant material;
  • detailed plant list specifying plants by botanical name, common name, quantity and sizes;
  • concept elevations illustrating design ideas for architectural structures;
  • grading plan (in collaboration with architect and civil engineer);
  • drainage plan (in collaboration with architect and civil engineer);
  • site lighting plan;
  • development permit application documents (if applicable);
  • perspective drawings and illustrations.

Other Consultants

In addition to the consultants providing normal engineering services, many other consultants may be involved at the design development stage of a project. See Chapter 2.3 – Consultants for a list of some of the consultants required for different architectural projects.

Coordination as a Defined Service

Clients may choose to enter a contractual relationship with engineering firms directly, rather than the architect retaining those firms. The role of the architect as coordinating consultant and the scope of services must be explicitly stated to ensure that all building and site systems are presented as an integrated whole. Although this may limit the architect’s liability exposure, it may also present challenges in engaging all members of the design team, as the architect does not have contractual control over the consulting design team. The architect should reinforce the importance of the role of the coordinating consultant to the client.

Regulatory Reviews and Approvals

The architect should have commenced a review with authorities having jurisdiction during the schematic design phase of a project (see Chapter 6.2 – Schematic Design and refer to RAIC Document Six); however, it is important to maintain contact with those authorities and to review certain details with them. Development permits and planning approvals are frequently obtained sometime after completing schematic design, or during design development. Although there is much variation between regions and municipalities, application for a building permit is usually made upon completion of construction documents. Typically, municipalities require that documents submitted for a building permit are intended for construction and are sealed by the architect of record. As well, a document of commitment may be required to be submitted by each professional on the design team prior to issuance of the full or interim permit. Regardless, keeping in contact with the authorities throughout the various project phases maintains their awareness, and promotes earlier resolution of any concerns they may have.

See also Chapter 2.4 – Building Regulations and Authorities Having Jurisdiction.

Building Cost Analysis

The architect or a specialist cost consultant ought to prepare an updated estimate of the construction cost during design development. Additional design information from the design development phase facilitates the preparation of a more complete and accurate estimate. With more detailed drawings and the outline specification, it can be anticipated that the construction contingency may be reduced; however, this is not always the case. See Chapter 4.2 – Construction Project Cost Planning and Control for information on construction cost estimates and the requirements at the design development stage.

Documentation and Presentation

The design development documents are used for a variety of purposes and by several participants in the design process. Some of the uses of these documents include:

  • client review and approval;
  • client marketing and media announcements;
  • reviews with authorities having jurisdiction and interested stakeholder groups;
  • subconsultant input and coordination;
  • update of construction cost estimates;
  • the basis to prepare the construction documents.

The documents should adequately describe and “finalize” the design for the remaining project efforts. For projects of a certain scale, design development documents may include three separate components:

  • drawings;
  • outline specifications;
  • a design report.

It is important at this stage of the project for the architect to present, review, and then secure formal, written approval from the client and other key stakeholders of major building components and the site design.


The drawings produced at the design development stage should provide adequate information to the client, consultants, and authorities having jurisdiction to explain major components of the project. Depending on the size and complexity of the project and the services outlined in the client-architect agreement, the drawings may include the following:

  • the site plan (in some jurisdictions, it is necessary to prepare a detailed site plan for site plan approval or the site plan control process at this stage);
  • all floor plans and all building elevations;
  • building sections;
  • un-rendered isometric views to explain stairs or complex elements which are difficult to understand on a 2-D drawing;
  • plans describing the structural, mechanical and electrical systems (for mechanical and electrical systems, these are usually presented diagrammatically rather than in detailed plans or sectional views);
  • details of significant design features and building materials;
  • any special exiting or code-related plans needed to explain how the design complies;
  • preliminary furniture and equipment layouts to be satisfied that everything fits and is functional;
  • presentation drawings which might include computer renderings, colour boards, interior and exterior views.

Refer to RAIC Document Six, Schedule A – Services, for other presentation products such as 3-D scale models, animated “fly-throughs,” virtual reality “tours,” etc., which may add value (but at additional cost to the client).

Outline Specifications

A necessary component of the design development phase is preparation of an outline specification which describes the proposed materials and construction systems in general terms and provides basic information on appearance, texture, operating and performance criteria, etc. They express intention and inform the specifications which will be developed in the next phase of construction documents. There are standard formats available to use in composing these, including CSI/CSC UniFormat standard classification or other classification consistent with (for example) BIM execution plan or estimating framework. This preliminary description includes sections provided by mechanical, electrical, information technology and other subconsultants. (See Chapter 6.4 – Construction Documents – Drawings and Specifications.)

Design Development Report

For some projects it may be useful, or even a contractual requirement, to document significant design decisions and design criteria at the end of design development. This is especially true if risks to the project have been identified earlier, such as budget, schedule, constructability, or hazardous material removals. The report should address these issues and confirm that they have been addressed at this phase. This is usually accomplished by means of a design development report.

In an executive summary section, the design development report should provide clear information on the project’s internal design logic and the genesis of design decisions made to provide a reliable reference towards predicating downstream design decisions and to promote continuity.

The design development report is a tool for use by clients and, if made public, other project stakeholders such as adjacent property owners, residents and businesses. The report can also be useful in providing a better understanding of the design for those who may not be familiar with the project, such as:

  • arm’s-length staff in the architect’s office;
  • authorities having jurisdiction;
  • media articles or other public communication;
  • financial institutions which the client may approach for funding;
  • building occupants, users and facility managers;
  • another architect who may be working concurrently on construction documentation as part of a joint venture;
  • subconsultants and other members of the project team.

The report also serves as a record for the project if there is a lengthy approval period or delays.

The architect should review with the client the various stakeholder groups who may have access to the design report. A project risk is that stakeholders with an interest in obstructing project success may use the report to advance their interests. Content, including text, illustration, images, and the results of investigations, should be scrutinized to ensure accurate information is communicated honestly, and to address issues of interest to key stakeholder groups.

If the project is submitted for publication or in an award competition, the design development report can serve as a source for images and confirming the design vision (used with the client’s knowledge and permission, depending upon the engagement contract in place).

A preliminary analysis of the proposed design with respect to compliance with the appropriate provincial building code is often included in the design report. Although optional, it is recommended, as it provides a foundation for reviewing the construction documentation. A “Suggested Table of Contents for a Design Development Report” is provided in Appendix A at the end of this chapter.

Design Development Phase Project Management Report

Accompanying each design phase report to the client, the architect is advised to provide a design project management report. Where the design development report pertains to the “product” of the design project, the project management report contains important information about the process. This report keeps the client abreast of the design project progress, successes, challenges, work complete and work remaining. The report should include:

  • work breakdown structure showing work completed, work in progress, and work not yet started;
  • updated project schedule;
  • updated risk register;
  • any updated project planning documents, including stakeholder and communications management plans.


See the “Checklist for the Management of the Architectural Project” in Chapter 5.1 – Management of the Design Project, which lists management tasks to be undertaken prior to and during the design development phase.


Allen, Edward, and Joseph Iano. The Architect’s Studio Companion: Rules of Thumb for Preliminary Design, 6th Edition. Hoboken, NJ: John Wiley & Sons, 2017.

Boecker, John, et al. The Integrative Design Guide to Green Buildings: Redefining the Practice of Sustainability. Hoboken, NJ: John Wiley & Sons, 2009.

Hamilton, D. Kirk, and David Watkins. Evidence-Based Design for Multiple Building Types. Hoboken, NJ: John Wiley & Sons, 2009.

Ostime, Nigel. RIBA Job Book, 9th Edition. London, RIBA Publishing, 2013.

Sinclair, Dale. Guide to Using the RIBA Plan of Work 2013. London: RIBA Publishing, 2013.

Sinclair, Dale. Assembling a Collaborative Project Team: Practical Tools Including Multidisciplinary Schedules of Services. London, RIBA Publishing, 2014.

WBDG Aesthetics Subcommittee. “Engage the Integrated Design Process.” Whole Building Design Guide, October 17, 2016., accessed April 27, 2020.