Accessory Dwellings

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Building design and construction process – step by step

Reasonable people may disagree, but here are the sequential steps in designing and building an ADU. This is an approximation of the steps for my ADU project, anyway. This was for an ADU built in Portland, Oregon. Slab on grade, stick frame construction—pretty standard ADU construction for this area.
Design Process
  • Funding
  • Brainstorm with other funder/executors
  • Talk to City Planner
  • Rough sketch some ideas with executors/friends
  • Talk to neighbors
  • Integrated Design Process
  • Interview architects (test them with some small space design questions: eg. What are a couple things that you would do to make a small space feel and act bigger? tall ceilings, join living/dining room, high windows, coupling functionality
  • Find builders and subs (ideally, you want to have identified a builder, plumber, mechanical, electrical subcontractor)
  • Architect draws up schematics for consideration
  • Have meeting- talk through design goals
  • Schematic refinement
  • 3D model (use SketchUp)
  • Develop drawings for City
    • Permit process- In Portland, processing takes 10 days for new construction, then another 10 days for corrections
  • Permits (see separate post about design and permitting)
Construction Process
  • Break Ground
  • Excavation
  • Foundation
    • Concrete Forms
    • Pour Foundation Wall
    • Concrete Slab Pour
      • Gravel
      • Water Barrier
      • Rigid Foam
      • Rebar (and PEX tubing for radiant floor heating)
      • Pour Concrete for Slab
  • Utilities
    • Sewer, Electrical, Water, Gas
  • Framing
    • Balloon Framing
    • Sheathing
    • Roof
    • Stairs
    • Windows
  • Roofing
  • Weather Resistant Barrier
    • Rain Screen
  • Rough Plumbing
  • Mechanical Sytems
    • HVAC
  • Lighting and Electrical
    • Ambient
    • Task
    • Accent
    • Perimeter
  • Air Sealing
  • Insulation
    • Spray Foam, Blown-in Insulation, or Batt Insulation
  • Drywall
    • Sheetrock, Mudding, Sanding, Primer
  • Siding
  • Flooring
  • Tiling
  • Painting
  • Cabinets, Shelving
  • Finish Plumbing
  • Finish Electrical and Lighting
  • Certificate of Occupancy
  • Modifications
  • Moving In

About Kol Peterson

Kol is an ADU advocate with a background in environmental planning. Read more here:

3 comments on “Building design and construction process – step by step

  1. SAndeep
    December 23, 2012

    Thank you sir

  2. Muhammad.
    October 3, 2013

    This was extremely helpful. Really appreciate it.

  3. Pingback: The Second Coming of Detached ADUs in Portland | Accessory Dwellings

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This entry was posted on November 9, 2011 by in Design & Build and tagged .
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