AIA NTAP Conference Set Based Design

Set-based Concurrent DesignEric Peabody

The Design Partnership ■

Architects + Planners

415 345-3813

[email protected]

Set-based Concurrent Design What is Set-Based? Set-Based Detailing Set-Based Design Choosing by Advantages Results

Why Do We Care?

What is Set-Based Design?

• Iteration in design is part value added and part waste– Understanding the problem and range of

solutions is value added– Rework and time delay is waste

• “Posing alternative design solutions as sets, rather than as point solutions is the strategy at the heart of…set-based design.”

• (Ballard, Lean Construction Institute, “Positive vs Negative Iteration in Design”)

Iterative Loops

Set-based Design

Iterative Design Set-Based Design• Sequential processing adds

time• Release incomplete work for

others to start evaluating• Simultaneous evaluation of

options

• Select best alternative as quickly as possible to move to next stage

• Carrying multiple options allows more time for analysis

• Defer commitment to avoid premature decisions with incomplete knowledge

• One design contribution can invalidate all previous work

• Identifying a problem with an option reduces the design space but does not trigger rework

Set-Based Detailing

SET 1

SET 2SET 3

Set-Based Design1. Divide design into interchangeable

chunks

2. Multiple simultaneous designs for each chunk

3. Evaluate Combinations

4. Select a combination set• Choosing by Advantages

5. Swap chunks at roadblocks

VA Palo Alto, Aquatic Center

Design Sets: Massing

Design Sets: Roof Structure

Design Sets: Skin Design

Design SetsCombinations: n1*n2*n3…nn= many sets

Massing: 7 optionsRoof Structure: 4 optionsSkin Design: 6 options

7*4*6=168 design sets

Which is the best option?

Choosing by Advantages• The Fundamental Rule of Sound Decision-making:

• Decisions must be based on the importance of advantages.• Pros & Cons = double counting

1. Identify Attributes:• Cake vs Cereal for Breakfast

• Calories• Taste

2. Identify Difference in Attribute Value:• Cake for breakfast = 500 calories• Cereal for breakfast = 200 calories

• Difference = 300 calories

Choosing by Advantages3. Identify Advantage

• Calories:• Cake has 300 more calories• Cereal has 300 fewer calories• Advantage:

• Cereal’s advantage is 300 fewer calories • Cake has no calorie advantage

• Taste: • Cake tastes very good.• Cereal tastes okay.• Advantage:

• Cake’s advantage is it tastes much better • Cereal has no taste advantage

Choosing by Advantages4. Evaluate the Importance of the Advantage

5. Select the option with the highest Advantage• Cereal for breakfast

Cake CerealCalories

No Advantage 0 300 Fewer Calories 10

Taste Tastes Much Better 5 No Advantage 0

5 10

Selecting an Option

9 55 0

0 12 1

0 88 0

0 106 10

0 83 3

7 50 0

16 3724 14

The Design Partnership LLP

Architects + Planners

Swap Chunks• Initial Client Selection

• Massing: Courtyard• Roof Structure: Bow String• Skin Design: Green Screen w/ Translucent Top

• Road block 1: Roof maintenance safety• Keep Massing & Skin Design• Trade Roof Structure: Flat for Bowstring

• Road block 2: 30% scope increase• Keep Skin Design & Roof Structure• Trade Massing: New Massing Option

• Road block 3: Contextuality• Keep Massing & Roof Structure• Trade Skin Design: Rainscreen for Green Screen

The Design Partnership LLP

Architects + Planners

Radically Accelerated Schedule

• Typical Project Schedule: • 30 to 45 minutes per SF for design.

• Radically Accelerated Schedule:• 30,000 SF in 4 months – Programming through CD

3 minutes per SF for design (10 to 15 times faster)

Set-based Concurrent DesignEric Peabody

The Design Partnership ■

Architects + Planners

415 345-3813

[email protected]