Engineering (rough-in) — Hidden systems before closure
This stage covers installation of concealed engineering systems prior to closing or finishing works: electrical routes, junction boxes and panels; hot and cold water lines; sewer runs and fan vents; pumps, tanks and associated assemblies; and low-voltage cabling. All hidden works are common practice to record with photo/video evidence and to coordinate with structural, finishes and inspection requirements. Progress checks, pressure/leak tests and labeling are typically completed before coverings are installed to avoid costly rework.
Use this stage across the product
The same stage should connect the budget model, control checklist, and cost-of-error review.
Overview
The engineering rough-in stage establishes the concealed infrastructure that will remain behind finishes. Work typically includes laying cable routes and conduit, setting electrical boxes and a service panel provision; running hot and cold water distribution and installing drain lines and soil stacks; providing fan vents and vent penetrations; mounting pump sets and tanks in their rough positions; and routing low-voltage pathways for data, security and automation. Coordination with structural elements, waterproofing and ventilation paths is essential. Common practice requires pressure/continuity checks, photo/video records, clear labeling and formal handover of as-built information before closing surfaces to reduce risk of hidden defects or access complications.
What is included
- Electrical rough-in: conduits, cable routes, boxes and preliminary panel placement
- Plumbing rough-in: hot and cold water mains, distribution stubs and isolation points
- Sewer and soil stacks: horizontal runs, vertical risers and connections to fixtures
- Fan vents and vent penetrations for drainage systems
- Rough mounting and connection of pumps, tanks and basic pump station piping
- Low-voltage rough routes for data, security and automation cabling
- Photo and video documentation of all concealed works and tests
- Basic labeling and as-built notes for later trades and inspectors
Main cost drivers
- Project complexity and number of service runs (electrical circuits, water lines, drains)
- Accessibility and need for chases, cores or structural penetrations
- Coordination and rework due to clashes with structural or MEP elements
- Quality and type of materials and components specified
- Extent of testing, inspections and required documentation
- Site logistics, sequencing and specialist labor for pumps or low-voltage systems
- Requirement for temporary systems, isolation valves or permit-related work
Common risks and mistakes
- Routing conflicts with structure or other trades because of poor coordination
- Insufficient slope on drainage runs leading to poor drainage or blockages
- Incorrect positioning of boxes, stacks or trap locations relative to finishes
- Inadequate protection of cables and pipes before finishing works
- Missing or incomplete photo/video records causing disputes later
- Poorly secured pumps/tanks or lack of vibration/isolation measures
- Unlabeled circuits or unrecorded changes leading to access issues
QA checklist before closing
- Verify routes and positions against design and finishes drawings
- Confirm correct slopes on drainage lines and sealed trap locations
- Pressure test water and air test drainage where applicable and record results
- Check conduit continuity, box placement and provision for panel clearance
- Ensure pump and tank mountings, supports and isolation are in place
- Label circuits, lines and low-voltage routes; collect as-built notes
- Capture photo/video at agreed milestones and attach to record
- Obtain required permits/inspector sign-offs before covering
Sub-stages
Electrical rough-in includes laying conduits and cable trays, positioning junction boxes and allocating space for the distribution panel. The work focuses on route planning, protection for later finishes, and leaving service entries accessible. Coordination with structural openings and other services is typical. Continuity checks, conduit fill consideration and photographic records are common practice prior to wall or ceiling closures.
Common issues
- Boxes set at wrong depth for finishes
- Conduits clashing with plumbing or HVAC penetrations
- Insufficient conduit capacity for intended wiring
- Lack of protective sleeves at floor or roof penetrations
Quality checks
- Verify box locations against layout and elevation drawings
- Check conduit routes for bends, supports and fill limits
- Document panel space and meter location provision
- Photograph all runs and junctions before closing
Plumbing rough-in covers routing hot and cold water supply to fixture locations, installing stub-outs, isolation valves and leaving connections for final fittings. Work typically includes pressure testing and thermal insulation where required. Coordination with finishes and fixture locations is essential to avoid rework. All hidden piping is usually documented with photo/video and as-built notes before coverings are applied.
Common issues
- Incorrect stub lengths or locations for final fixtures
- Missing isolation valves at accessible points
- Inadequate support or unsecured pipe runs
- Poor coordination causing clashes with electrical or structural elements
Quality checks
- Conduct pressure tests and record outcomes
- Confirm stub positions and heights against fixture schedules
- Verify pipe supports and spacing per common practice
- Capture photo/video evidence of concealed piping
This package includes installing horizontal sewer runs, vertical soil stacks and connections to fixtures and main drainage. Ensuring correct slope, trap locations and ventilated connections is critical. Work typically requires temporary access for testing and may need coordination with structural penetrations. Leak testing and photographic documentation of runs and joints are common practice before closing ceilings or floors.
Common issues
- Insufficient slope on horizontal runs
- Incorrect stack alignment or offsets creating stress
- Missing cleanouts or access points
- Improper sealing at joints or penetrations
Quality checks
- Verify slopes and alignment against design tolerances
- Inspect joint integrity and sealing methods
- Ensure cleanouts are accessible and labeled
- Perform and document leak/air tests where applicable
Ventilation rough-in involves creating vent stacks, fan outlets and penetrations through roofs or walls to ensure proper sewer system venting. The scope includes positioning, support and weatherproofing details for eventual fan installation. Coordination with roofing and structural trades is typical, and documentation of penetration locations and flashing details is common practice before finishing work proceeds.
Common issues
- Incorrect penetration locations relative to roofing details
- Insufficient support for vent stacks
- Poor weatherproofing around penetrations
- Vent runs blocked or reduced by other installations
Quality checks
- Confirm vent paths and termination points match drawings
- Check structural supports and flashings at penetrations
- Document clear access for future fan installation
- Photograph vent runs and roof penetrations
Rough installation of pumps and tanks covers setting baseplates or supports, basic piping connections, and routing electrical and control pathways to the pump area. Work focuses on correct positioning, vibration/isolation provisions and space for maintenance. Initial connection checks and securing of equipment are common, with photo/video records and provisional labeling before final commissioning.
Common issues
- Poorly aligned pump mounts causing vibration
- No access clearance for maintenance or replacement
- Inadequate supports for associated piping
- Missing isolation or check valves as required
Quality checks
- Verify base and alignment provisions for pumps
- Check access clearances and service routes
- Confirm provisional piping arrangement and supports
- Record installation with photos and preliminary notes
Low-voltage rough-in establishes pathways for data, security, audio/visual and automation wiring. The focus is on conduit or tray routing, service entry points and reserved spaces for termination. Coordination with the electrical distribution and other services is important to reduce interference. Best practice includes labeling, separation from power cables, and photo documentation to aid final termination and testing.
Common issues
- Mixed routing with mains power causing interference risks
- Insufficient conduit or sleeve capacity for future upgrades
- Unclear labeling leading to miswiring later
- Poor coordination with furniture or equipment layouts
Quality checks
- Ensure separation from high-voltage power runs
- Verify conduit capacity and pull points
- Label routes and capture as-built photos
- Confirm termination locations align with room layouts
FAQ
Photo and video should be taken at agreed milestones: after routing is complete but before coverings, after pressure or leakage tests, and after any major changes. Consistent documentation provides evidence for inspections and reduces disputes. Records are typically stored with as-built notes and shared with relevant trades and inspectors.
Modifying concealed systems after closure typically depends on access and extent of change. Minor adjustments may be possible via access panels or selective openings, but major changes commonly require removal of finishes and can cause delays. It is common practice to resolve design and coordination issues at the rough-in stage to avoid costly rework.
Responsibility for sign-off usually involves the installing contractor, project manager and relevant inspector or authority having jurisdiction. Internal QA personnel commonly verify tests and documentation first. Final sign-off depends on meeting contract requirements, successful tests and provision of photo/video and as-built records.
Because cost volatility or site-specific variables increase uncertainty.
Related glossary
Next steps
Continue budgeting in the calculator or move to the next stage of the project.