Free planning guide
How to test the property, define the living arrangement, and coordinate a compact home from feasibility through final approval.
Who this is for
For homeowners exploring an attached accessory dwelling unit, basement conversion, garage conversion, or detached backyard home for family, rental, caregiving, work, or long-term flexibility.
How to use it
An ADU or DADU is a complete dwelling in a small footprint. Its success depends on property rules, access, privacy, utilities, structure, drainage, fire and life safety, and everyday livability being considered together. Start by testing the property and intended use before falling in love with a plan. Use this guide to prepare for a useful conversation, not to diagnose the house from a distance. Write down assumptions as assumptions. When new information changes the plan, ask for the scope, cost, and schedule effect in writing before work continues whenever practical.
Six planning principles
Define the result before the products. A strong brief describes what daily life should improve, what must remain, and which compromises are acceptable.
Compare scopes, not just totals. Two proposals can look similar while assigning demolition, permits, protection, selections, restoration, and unknowns very differently.
Make decisions in dependency order. Layout and performance choices come before finishes; products that affect rough-in or fabrication must be known before those steps are released.
Treat unknowns honestly. Visible conditions, reasonable expectations, and concealed possibilities are different categories. Investigation can reduce uncertainty, but some conditions remain unknowable until opening.
Protect quality beneath the finish. Structure, water control, fire and life safety, utility work, ventilation, and manufacturer requirements should not be traded away for a cosmetic upgrade.
Keep one current record. Consolidated decisions, drawings, selections, questions, approvals, and changes help the homeowner and every trade work from the same information.
The project path
A useful process is more than stage names. Each phase should resolve decisions and leave behind clear information the next phase can rely on.
Define who may live there, desired independence, privacy, accessibility, parking assumptions, outdoor space, and long-term use.
Homeowner decisions
Choose the intended occupancy pattern and rank size, privacy, flexibility, and investment priorities.
Expected output
A use brief and clear criteria for comparing attached, converted, and detached options.
Review lot information, easements, existing structures, utility records, permit history, trees, slope, drainage, and local rules with the proper sources.
Homeowner decisions
Provide known documents and authorize survey, records, or specialist research when needed.
Expected output
A feasibility summary identifying viable concepts, constraints, and unanswered property questions.
Study construction access, excavation, foundation approach, utility routes, soil or slope concerns, and connections to the primary home. Conversion projects also require close review of height, moisture, egress, structure, and fire separation.
Homeowner decisions
Select investigations needed to reduce major uncertainty.
Expected output
Measured information, site observations, and recommendations for survey, civil, structural, or utility input.
Test placement, floor plan, daylight, storage, entries, sound separation, exterior form, and relationship to neighbors and the main home.
Homeowner decisions
Choose a concept and decide where compact design or added area best serves the use.
Expected output
A preferred concept with preliminary systems, site work, and scope assumptions.
Coordinate architecture, structure, energy information, site requirements, MEP systems, and the permit package. Track agency comments without treating review time as guaranteed.
Homeowner decisions
Approve design milestones and respond to consultant or agency decisions.
Expected output
Coordinated permit documents, submitted application, correction log, and issued set when approved.
Finalize windows, exterior materials, cabinets, fixtures, appliances, lighting, flooring, and equipment; connect each choice to procurement and installation.
Homeowner decisions
Meet selection deadlines and approve scope, allowances, exclusions, and logistics.
Expected output
Construction agreement, selection schedule, purchasing plan, site logistics, and baseline schedule.
Complete site work, foundation, structure, weather enclosure, rough systems, insulation, interiors, fixtures, and site restoration with required inspections and documented hold points.
Homeowner decisions
Review changes, verify intended operation, and complete the final walkthrough.
Expected output
A completed dwelling with final approval status, manuals, records, finish references, and maintenance guidance.
Scope and condition check
Cost and schedule
Early numbers become more dependable as site facts, design, selections, responsibilities and unknowns become documented.
Detached construction, conversions, and additions have different foundation, tie-in, fire-separation, and access demands.
Available capacity, trench routes, panels, pumps, meters, and connection points can materially affect scope and sequence.
Slope, excavation, groundwater, soils, retaining, and stormwater requirements may require specialist design or added work.
Small rooms still contain a full kitchen, bath, mechanical system, storage, and detailed coordination.
Survey, architecture, structural, civil, energy, utility, and agency work can overlap but do not run on guaranteed timelines.
Backyard work may require narrow-path material movement, limited equipment, neighbor coordination, or special staging.
Windows, equipment, cabinets, doors, utility components, and exterior products may control portions of the schedule.
Attached work and utility tie-ins can require protection, temporary outages, finish restoration, and code-related upgrades.
Before construction
For this project
Questions worth asking
Pause and verify
Completion and stewardship
Save the records with the home. They support operation, maintenance, warranty questions and future work.
Professional verification: Rules for ADUs & DADUs, permits, utility requirements, and property eligibility vary and can change. Confirm current requirements with the local authority and qualified design, engineering, utility, and construction professionals. Do not rely on this guide as a zoning, code, rental, tax, financing, or legal opinion.
Connect with Ideal
If you are weighing a basement unit, garage conversion, addition, or detached backyard home, start with the property and intended use. Ideal Construction & Renovation can help organize the feasibility questions and build a responsible path toward design and construction.
Start with a conversation
Share what is not working and what you want your home to feel like. Christian will help identify the next step.