Understanding SD, DD, and CD in the AEC World

What are the AEC different design phases?
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In the dynamic world of architecture, engineering, and construction (AEC), professionals use various terminologies and acronyms to describe different stages of a project. Among these, SD, DD, and CD hold significant importance. Let’s delve into what these terms mean and their benefits in the AEC industry.

What is Schematic Design (SD)?

Schematic design, also known as SD, is the first phase in the architectural design process. In this stage, architects and designers work together with clients to find out their needs, vision, and objectives for the project. The emphasis is on drafting the initial sketches and conceptual drawings that capture the main idea of the project.

SD enables architects to create different design options, concepts, and ideas, thus helping clients see the project’s aesthetics and layout. In this stage, design problems and opportunities are identified. This helps the client make wise decisions. These decisions are based on the project scope and cost estimates. Architects, designers, and consultants can find and solve design issues. This results in fewer costly modifications in later stages. The SD stage promotes close collaboration between teams. These teams include architects and clients. This collaboration ensures designs align with the client’s vision and requirements.

The SD phase typically includes:

  • At first, having the floor plans, elevations, and sections is a way to have a rough outline of the whole project.
  • The building’s size and shape are being used as a basis for identification.
  • The first task of that stage is to find out what the primary building systems (structural, mechanical, electrical, and plumbing) are.
  • Calculating the project’s cost from the conceptual design is merely a rough estimate. It doesn’t fully depict the future events in the construction.

The primary purpose of the SD phase is to fulfill the client’s vision and program requirements. It’s crucial to obtain the client’s approval before moving on to the next stage.

SD (Schematic Design)
Image Source: Moss Architecture

Benefits of Schematic Design

The schematic design phase is the basis of any AEC project. It provides several benefits:

  • Client Engagement: SD enables architects to collaborate with clients so that the project will follow their vision and requirements.
  • Problem Identification: In the beginning, we detect potential design challenges and opportunities, and we solve them on time.
  • Cost Estimation: Initial cost estimates are derived from the project’s scope. This helps clients make informed decisions. in turn, assists the clients in making the right decisions.
  • Design Exploration: Architects can experiment with various design ideas and concepts, thus creating a space for creativity and innovation.

What is Design Development (DD)?

The Design Development stage, known as DD, follows the Schematic Design phase. In this phase, the design team refines the initial sketches. They create a more precise design based on the SD concepts.

During design development, architects collaborate with various stakeholders. These include engineers and contractors. They work together to address structural, mechanical, and electrical issues. The main goal is to create accurate drawings and 3D models. They also select materials that align with the project’s functional needs and budget.

The DD phase typically includes:

  • The first step in the design process is the development of detailed floor plans, elevations, and sections.
  • Outlining the materials and finishes that are to be employed
  • The different building systems (structural, mechanical, electrical, and plumbing) need to be coordinated.
  • The cost estimate of the project was refined based on the more detailed design.

The main goal of the DD phase is to ensure that we completely coordinate the design and all stakeholders agree before moving on to the construction documents phase.

Design Development
Image Source: Moss Architecture

Benefits of Design Documentation

The Design Development phase modifies the ideas that were made in the SD phase. It offers several advantages:

  • Detailed Design: DD is mainly concerned with making the drawings, 3D models, and the choice of materials that meet the requirements of function and budget.
  • Collaboration: Architects, engineers, and contractors work together to solve the problems of the structure, the machinery, and the electricity.
  • Cost and Time Savings: Studies show that the use of professional drawing services during the DD phase can lead to up to 15% time savings and 10% cost savings on building projects.

What is construction documentation (CD)?

Construction documentation (CD) is the phase where the finalized design is turned into detailed instructions for the construction team. It contains in-depth drawings, detailed specifications, and technical documents that direct the construction process; thus, the construction becomes accurate and the design vision is followed. This stage is essential for a successful and fast construction process.

The CD phase typically includes:

  • Floor plans, elevations, sections, and details are the essential elements that have to be provided in the building design of a project.
  • It will define the different materials, finishes, and equipment to be used.
  • Giving a comprehensive description of the building systems (structural, mechanical, electrical, and plumbing) is the key to conveying all the necessary information to authorities.
  • Its detailed specifications outline the materials and workmanship for construction.

The main goal of the CD phase is to present a complete and written set of documents that stakeholders can use for bidding, permitting, and construction.

Construction Documentation
Image Source: Moss Architecture

Benefits of Construction Documentation

The construction documentation phase is the most important part of any AEC project to be realized. It has several benefits:

  • Detailed Documentation: CD offers complete drawings, specifications, and technical documents, which are a must for the construction.
  • Clear Communication: The documents generated in the CD phase are very clear and detailed and will help the construction team build without any mistakes or confusion.
  • Regulatory Compliance: The CD phase makes sure that all designs are in line with the local building codes and regulations.

The Importance of SD, DD, and CD in the AEC Industry

 Let’s delve deeper into the importance of each phase (SD, DD, and CD) in the AEC industry:

Schematic Design (SD)

During the schematic design phase, designers create the project’s general outlines. The collaboration needs to be successful, as it includes discussions between architects, engineers, and clients to get a clear idea of the project’s requirements and objectives. This phase helps in minimizing errors because it enables the detection and solution of possible design problems at the beginning. It also helps with expense management by creating preliminary cost estimates based on the project’s scope, allowing clients to make informed decisions.

Design Development (DD)

Design development (DD) is the phase when the schematic designs are more refined and detailed. This phase is crucial for collaboration since it includes different parties, such as engineers and contractors, to solve structural, mechanical, and electrical problems. The DD phase is beneficial for mistake reduction as it enables the removal of design and structural errors before construction starts. Besides, it also helps in expense control because it gives a more precise estimate of the project cost through the detailed design.

Construction Documentation (CD)

Construction documentation (CD) is the last stage before construction starts. Effective collaboration is essential, as it provides the construction team with precise and detailed instructions, ensuring everyone understands their expectations. The CD phase reduces mistakes and the likelihood of construction errors by providing detailed information. It also ensures cost savings by ensuring the project’s completion according to the finalized design and within the estimated budget.

Conclusion

Anyone involved in the AEC industry must understand the roles and benefits of SD, DD, and CD. These stages not only help in the successful execution of projects but also ensure effective collaboration among various stakeholders. By understanding these stages, one can ensure a smooth and efficient construction process, leading to successful project completion.

Remember, in the AEC world, SD means schematic design, DD means design development, and CD means construction documents. Each of these stages plays a vital role in the successful completion of a construction project. So, the next time you come across these acronyms, you’ll know exactly what they mean and their significance in the AEC industry.


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