# What happens during the design phase of a custom home?

**Short answer:** The design phase of a custom home usually runs four to eight months, moving through programming, schematic design, design development and construction documents. Each stage closes a layer of decisions and hands work to a widening consultant team. The range is set less by drafting speed than by how fast the owner approves each stage.

## Key facts

| Fact | Value | Source |
| --- | --- | --- |
| Typical design phase duration | Four to eight months, programming through construction documents |  |
| Stages inside design | Programming, schematic, design development, construction documents |  |
| Consultants typically engaged | Structural, civil, geotechnical, energy, landscape, lighting, survey |  |
| Sets the pace | Owner decision speed, not drafting speed |  |
| Most expensive habit | Reopening a decision after the next stage has started |  |

## Design is a decision sequence, not a drawing sequence

Start with the number, because it is the thing most owners want first. On a
fully custom home, plan on four to eight months from the first programming
meeting to a permit-ready set. Straightforward lots with decisive owners land
near the bottom of that range. Hillside, coastal and heavily constrained sites,
or any project where the plan keeps reopening, run to the top of it and past it.
Permitting is a separate stretch of calendar that begins after this one.

Most owners experience design as a long quiet stretch where somebody is off
drawing something. What is actually happening is a series of decisions being
closed, one layer at a time, each layer narrowing the set of things that can
still change cheaply.

That is the entire logic of the phase. In the first month, moving a wall costs
an eraser. Six months later the same wall means revised structural
calculations, a new energy compliance report, a redrawn foundation plan and a
reprinted set. If the drawings are already in review, it also means a
resubmittal.

So the useful way to read the design phase is not as drafting time. It is as a
running clock on how expensive your remaining decisions are. Understanding the
stages is really about understanding when each category of decision has to be
finished.

## The four stages, and what the owner owes at each

### Programming

The shortest stage and the one most often skipped. Programming is where the
house gets defined in words before it gets defined in lines: how many bedrooms,
how the family actually uses a kitchen, whether guests stay for a weekend or a
season, what the budget really is and which parts of it can flex.

What the owner owes here is honesty and a survey. A boundary and topographic
survey, a preliminary title report and any existing drawings for the property
should be in hand before design starts, because setbacks, easements and
elevations all constrain the first sketch.

### Schematic design

Massing, floor plates, orientation, roof form, the relationship between the
house and the site. Drawings are still loose on purpose. This is the stage where
big moves are cheap, so it is the stage where they should all happen.

What the owner owes is a decision on the plan. Not a preference, a decision. The
single most common cause of a stalled design phase is a schematic plan that was
never truly approved and keeps reopening after later work has been built on top
of it.

### Design development

The plan stops moving and everything inside it gets resolved. Wall assemblies,
window sizes and operation, ceiling heights, stair details, structural system,
mechanical approach, cabinetry layouts, appliance and fixture selections. This is
where the consultant team does most of its work, and where the drawings start
to describe a real building rather than an idea.

What the owner owes is selections. Every unmade selection at the end of design
development becomes either a placeholder that gets corrected later or an
allowance that becomes a change order in construction.

### Construction documents

The permit and build set. Dimensions, schedules, details, structural sheets,
energy compliance forms, plumbing and electrical layouts, specifications. Nothing
conceptual happens here. It is the translation of settled decisions into a
document a plan checker can review and a builder can price and construct.

What the owner owes at this stage is restraint. A change during construction
documents is not a small change, because the drawings are now cross referenced.
One window edit can touch the floor plan, elevations, sections, the window
schedule, the structural sheets and the energy report.

## The consultant team, and when each one arrives

The architect is the constant. Everyone else joins at a specific point, and each
handoff is a place the schedule can stall while one consultant waits on another.

| Consultant | Usually joins | What they wait on |
| --- | --- | --- |
| Surveyor | Before programming | Access to the site and the title report |
| Geotechnical engineer | Schematic design | Site access, drill rig scheduling, lab time |
| Civil engineer | Schematic to design development | Approved site plan and survey |
| Structural engineer | Design development | A plan that has stopped changing |
| Energy consultant | Late design development | Final window and glazing specifications |
| Landscape architect | Design development | Grading concept and hardscape footprint |
| Lighting designer | Design development | Reflected ceiling plans and finish palette |

Two of those have real lead time that owners rarely plan for. A geotechnical
report requires field drilling and laboratory work, and the structural design
cannot be finished without it. Energy compliance depends on final glazing, which
means a late window change ripples into a report that has to be rerun.

On hillside and coastal parcels the list grows. Arborists, hydrologists,
biologists and geologists all show up when the site or the jurisdiction requires
them, and each one is a separate scope, a separate fee and a separate calendar.

## Where design phases quietly stall

**A decision gets reopened.** The plan was approved, then revisited after the
structural engineer started. The engineering is billed twice and the stage
restarts. This is the largest single source of lost time in design.

**Selections lag the drawings.** Cabinetry, appliances and windows get treated as
finish decisions when they are actually rough-in decisions. Custom millwork in
particular has to be coordinated during design rather than after framing, which
is why [custom cabinetry](/custom-cabinetry) belongs in design development and
not in a later conversation.

**Nobody prices the design until it is finished.** A set that is fully drawn and
thirty percent over budget has to be redesigned, and redesign at construction
document stage is the most expensive redesign there is. A builder involved
during design catches this while it is still a sketch, which is why pricing runs
alongside the drawings on
[residential development](/residential-development) projects rather than waiting
for a finished set.

**Approval authority is unclear.** When two people share the decision, hold
different priorities and have never agreed who breaks a tie, the rounds multiply
without converging. Name the decision maker at the start.

## What to have ready before the first design meeting

**A survey and a title report.** Both, current. Setbacks, easements and grade
drive the first sketch, and design done without them tends to get redone.

**A written program.** One page describing how the house has to work, not a
folder of images. Images are useful later, for character. They cannot resolve a
plan.

**A real budget with a stated priority.** Not a ceiling you hope nobody hits. The
number, plus which part of the house matters most if something has to give.

**A named decision maker.** Someone who can approve a stage and keep it
approved.

**A geotechnical scope, if the site suggests one.** On a slope, a fill lot or
anywhere near a hillside, commission it early. Everything structural waits on
that report.

## Why decision speed governs the calendar

The gap between the four month version of this phase and the eight month version
is almost never drafting speed. It is the accumulated time approvals spent
sitting on somebody's desk, plus the cost of every decision reopened after the
next stage had already been built on top of it.

Design is a chain of dependencies. The structural engineer waits on a fixed
plan. The energy consultant waits on final windows. The civil engineer waits on
a settled footprint. Every day an approval sits with the owner is a day the
whole chain waits, and every reopened decision unwinds work that was already
paid for.

That is also why compressing design rarely works. Hiring more drafters does not
speed up a stage that is waiting on a selection, and skipping design development
does not remove the decisions, it just moves them into construction where they
cost more and arrive as change orders.

The practical target is simple: finish decisions in the stage that owns them.
Every stage that closes on time removes a whole category of change from the
stages after it, and that compounding is what separates a design phase that
lands near four months from one that runs past eight. It does more for a
schedule than anything a builder can do in the field.

## Frequently asked questions

### Who is actually on the design team besides the architect?

A custom home usually needs a surveyor, a geotechnical engineer, a structural engineer, a civil engineer for grading and drainage, and an energy consultant for California compliance. Landscape architects and lighting designers join on most fine residential projects, and hillside or coastal sites frequently add arborists, biologists or hydrologists depending on what the jurisdiction asks for.

### How many rounds of revisions are normal before drawings are final?

Two or three rounds per stage is healthy. One round usually means the owner has not really engaged with the drawings yet. Five or six rounds in a single stage means the underlying program was never settled, and the fix is to go back and resolve what the house needs to do rather than continuing to redraw options.

### Do finish selections have to happen during design?

The ones with structural or dimensional consequences do. Appliances, plumbing fixtures, windows, tile layouts and cabinetry all drive framing, blocking, rough plumbing and electrical placement, so they belong in the drawings rather than in the field. Paint colors and hardware finishes can wait. Anything with a rough-in or a long lead time cannot.

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Source: https://www.tricanagroup.com/insights/what-happens-during-the-design-phase-of-a-custom-home
Topic: Timelines & Process
Author: Hagop Sargisian, Tricana Group
Area served: Los Angeles County, CA; Orange County, CA
Published: 2026-05-26T09:00:00-07:00