Full-service home extension in Tokyo — from initial design through construction and final walkthrough, handled by ROCAS Corp.'s in-house residential team.
Consultation & site assessment
Design & scoped quote
Construction & project management
Final walkthrough & handover
Typical residential projects run 2–12 weeks depending on scope.
Most contractors subcontract out the trades that actually determine quality — flooring, electrical, wall finishes. ROCAS Corp. keeps those in-house, which means fewer handoffs, fewer scheduling gaps between crews, and a single team accountable for the finished result of your home extension.
You get one point of contact for the entire project, a written scope before any work begins, and a dedicated project manager who tracks the schedule day to day — so you're not the one chasing updates between separate contractors.
How much does home extension typically cost?
It depends on scope, finish level, and property size. Use our cost calculator for a ballpark figure, or request a quote for an exact number.
How long will the project take?
Typical residential projects run 2–12 weeks depending on scope. We confirm a firm schedule once scope is finalized during the consultation.
Do you handle permits and approvals?
Where applicable, yes — we manage the permit and building-management approval process as part of project management, so you don't have to navigate it alone.