Have the designer field-measure the existing house

What this step is

Your designer or an as-built measurement service shows up with a laser distance meter and spends a day inside and around the existing house, then takes another two to three weeks to draw it cleanly. The output is a set of existing-conditions sheets — floor plans, exterior elevations, and at least one section through the house.

Why field measurement matters

Older Portland houses are not square. Walls that look parallel are typically 1–4 inches off across a room. Floors slope. Ceilings vary. Designing a second story onto plan dimensions that turn out to be wrong by 6 inches over the building's length means corrections later — sometimes during framing, when corrections are expensive.

A field measurement records what's actually there: room sizes to the eighth of an inch, wall thicknesses (which tell the structural engineer about framing depth), window and door rough openings, ceiling heights (which usually vary in older houses), and the location of every plumbing fixture, electrical panel, and major mechanical equipment.

How it gets done

1. The designer (or a sub) walks the house room by room, capturing dimensions on a sketch.
2. Photographs every elevation, every interior wall.
3. Measures the exterior using the survey as the boundary reference.
4. Drafts the existing-conditions set in CAD or BIM.

What you get

• Existing-conditions floor plans for each level (basement, first floor, attic).
• Exterior elevations — all four sides, with window/door sizes and trim profiles.
• One or more sections through the house showing existing floor-to-ceiling heights, joist depth (if accessible), and roof framing.
• Photo log indexed to the plans.

This set is the foundation document for everything downstream: schematic design, structural engineering, energy compliance, the permit submittal, and the GC's bid scope.