Schematic design through design development

What this phase produces

By the end of design development you have:

• Floor plans for each existing and proposed level, with rooms labeled and dimensioned.
• Exterior elevations — all four sides of the house, with window and door locations and exterior materials.
• Building sections showing floor-to-floor heights, the addition's roof tie-in, any complex framing.
• A kitchen study — preliminary cabinet layout, island position, appliance placement.
• A 3D model or massing diagram that lets you understand the project three-dimensionally.
• A specifications outline for exterior materials and major interior finishes.

This isn't a permit set yet. Permit-set work happens in construction documents. But the design has to be right enough that the structural engineer can engineer to it and the energy consultant can run substantial-alteration analysis against it.

How the iteration works

Most owners go through 2–4 schematic rounds. Round 1 is the designer's first pass. Each round takes 2–4 weeks: designer presents, you live with it for a week, you give feedback, designer revises.

What to focus on:

• The kitchen layout. This is where most of the iteration happens. Get it right in schematic.
• Wall removals. Which walls come out is half-engineering, half-design. The designer flags the candidates; the structural engineer in the next step confirms which are feasible.
• Addition roof tie-in. A clean tie-in costs less and looks better. The designer should show you a section through the tie-in early.
• Window and door rhythm. New windows on the addition should match (or deliberately contrast) the existing house's rhythm.

What to push back on

• Scope creep. Each "while we're at it" gets its own line and its own decision against the scope memo.
• Designer's preferred details over your budget. A great designer respects the budget. A less-great designer designs at the top of the band and asks you to swallow it.
• Inflation of finish levels. Specifications written at "high-end residential" produce bids that exceed band-3 budgets. Pick the finish level that matches your scope memo, not the designer's portfolio.

What good looks like at the end of DD

The design feels resolved. The plans answer every question you've asked. The kitchen layout works on paper and would work in real life. The cost band has tightened from "wide" to "moderate." Time to engineer it.