Design an ADU around the property, the people who will use it, and the long-term role it should play. Builtech combines architecture, engineering, permitting, construction, and finish decisions in one custom design-build process.
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IS A CUSTOM ADU RIGHT FOR YOU?
When Custom ADUs Are the Right Fit
A custom ADU is appropriate when the lot is unusual, the primary home has a distinctive architectural language, the household has accessibility or multigenerational needs, the owner wants a specialized construction method, or the project has demanding fire, hillside, tree, utility, or privacy constraints. Custom design focuses effort where it adds real value rather than changing finishes on a generic plan.
IDEAL FOR
Irregular, sloped, narrow, or highly constrained lots
Aging-in-place or accessibility-focused living
High-end guest houses or long-term family residences
ICF, steel, highly noncombustible, or 3D-printed construction
Architecture that should complement an existing custom home
FROM FEASIBILITY TO CLOSEOUT
Builtech’s Integrated Custom ADU Process
The process is organized around setting the program and budget together, so the design responds to both aspiration and construction reality. Each stage has a defined decision, deliverable, and owner responsibility so design, permitting, pricing, and construction remain aligned.
01
Feasibility
Review the property, goals, ADU type, site constraints, utilities, access, budget, and schedule before committing to a design path.
02
Concept Design
Test placement, floor plan, massing, privacy, materials, and construction approach. Select a preferred concept and record unresolved questions.
03
Engineering + Permits
Coordinate architecture, structure, energy, utilities, fire, and site documents; submit a complete package and manage agency comments.
04
Preconstruction
Finalize scope, price, selections, permit conditions, utility tasks, schedule, long-lead materials, financing, and site logistics.
05
Construction + Inspections
Manage site work, structure, enclosure, systems, finishes, quality control, inspections, safety, communication, and changes.
06
Closeout
Complete final inspections, punch work, utilities, warranties, manuals, permit records, owner orientation, and project documentation.
PROPERTY FEASIBILITY
Property and Feasibility Review
Before design begins, Builtech evaluates the property as a complete system. The review identifies what appears feasible, what requires confirmation, and which decisions have the greatest effect on cost, schedule, and approval.
DESIGNED AROUND HOW YOU’LL LIVE
Design Priorities for a Better Custom ADU
A successful custom ADU should work as a home first. The design must balance efficient area, privacy, daylight, storage, utilities, durability, and the relationship between the ADU and the primary residence.
CONSTRUCTION + BUILDING SYSTEMS
Construction and Building-System Strategy
Custom design does not mean uncontrolled complexity. The strongest process establishes a clear program, target budget, approval path, and decision schedule before detailed design. Builtech compares structural systems and envelope strategies based on project goals, then coordinates architecture and engineering so the drawings are both buildable and permit-ready.
Project-Specific Options
Compare systems against the property, goals, and construction constraints rather than treating any method as a universal shortcut.
Coordinated Architecture + Engineering
Buildability + Permit Readiness
Decision Schedule
How Builtech Evaluates the Right Building System
Total Installed Cost
Compare the complete installed system cost, not only material pricing.
Site Access
Confirm that equipment, crews, and deliveries can reach the property safely and practically.
Structural Requirements
Match the approach to the site, design, engineering, and code requirements.
Energy Performance
Review insulation, air sealing, glazing, mechanical systems, and applicable energy requirements.
Fire Exposure
Evaluate exposure conditions and the project’s applicable fire-resilience requirements.
Moisture Management
Coordinate drainage, weather protection, wall assemblies, and durable transitions.
Trade Availability
Confirm qualified labor and specialty trades can support the selected approach.
Permitting
Evaluate integration with required documentation and agency review.
Schedule
Plan lead times, sequencing, inspections, and site logistics.
Long-Term Maintenance
Consider serviceability, finishes, durability, and owner expectations.
PERMITS + COORDINATION
Permitting, Utilities, and Code Coordination
The permit team develops the design within statewide ADU protections while checking the jurisdiction’s objective standards and project-specific overlays. Custom features that affect height, grading, retaining walls, fire access, drainage, utility service, or coastal review should be identified before the design becomes difficult to change.
Design Coordination
Develop a coordinated architectural set that responds to the property and the owner’s priorities.
Engineering Integration
Align structure, site work, and supporting consultants with the selected design path.
Energy + Building Systems
Coordinate the envelope, mechanical, electrical, plumbing, and applicable energy documentation.
Utility Planning
Evaluate service capacity, practical routing, and utility-provider requirements.
Fire + Site Review
Identify fire access, grading, drainage, and other project-specific conditions early.
Agency Comments
Manage applicable review comments while keeping the package coordinated.
BUDGET + SCHEDULE
A reliable budget is based on the property and scope—not a headline price per square foot. After the preferred concept is selected, Builtech develops a category-based budget and milestone schedule that identifies included scope, allowances, owner purchases, exclusions, contingency, utility responsibilities, and decisions required before construction.
RELATED ADU SERVICES
START WITH YOUR PROPERTY
Find Out What Your Property Can Support
Tell Builtech about your property, goals, intended ADU use, preferred project approach, budget range, and timing. The first conversation will identify the information needed to evaluate feasibility and define the most useful next step.
CUSTOM ADU FAQs
Frequently Asked Questions About Custom ADUs
Get answers to common questions about site-specific ADU design, preapproved plans, budget discipline, accessibility, and architectural fit.
Can we start with a standard plan and customize it?
How do you keep a custom ADU within budget?
Can a custom ADU be designed for aging in place?
Can Builtech match the main house?
What does Builtech review during a custom ADU feasibility study?
How are permits handled for a custom ADU?
Can a custom ADU use specialized construction methods?
What affects the cost of a custom ADU?
What happens after I request an ADU feasibility review?