Developer in Rolleston called us about a 6-unit townhouse development they were building. They hired a cheaper electrician to save money but halfway through the job the electrician disappeared - just stopped showing up. The developer was stuck with half-finished electrical, missed deadlines, and buyers waiting to move in. We came in, assessed what had been done, found heaps of code violations and dodgy work, basically had to redo most of it. Took us 3 weeks working overtime to get all 6 units finished properly and signed off. Developer said next time theyre paying for quality from the start instead of trying to save money and ending up spending more fixing problems. Thats pretty common with multi-unit developments - people dont realize how different they are from single houses.
Multi-unit electrical is more complex than regular residential. Youve got shared services, individual metering, body corporate requirements, council regulations. Needs electricians who know what theyre doing.
What Makes Multi-Unit Different
Multi-unit developments arent just multiple houses stuck together. The electrical setup is way more complicated.
Shared services mean you got common areas that need power - driveways, pathways, letterboxes, gates, gardens. This power gets split between all the units usually through body corporate.
Individual metering means each unit has its own power meter so owners pay for what they use. But you also need a meter for shared services.
Main supply comes in bigger - instead of one house getting 63 amps you might have 6 units needing 400+ amps total. Power company requirements are different for developments.
Fire safety rules are stricter. Interconnected smoke alarms, emergency lighting in common areas, fire alarm systems in bigger developments. All required by code.
Body corporate regulations affect how things get set up. Who owns what, who maintains what, how costs get split. Electrical design has to accommodate that.
Council consent process is more involved. More documentation, more inspections, stricter requirements than single dwellings.
Did a 4-unit development in Addington where the developer wanted to save money by having units share services where possible. We designed it so laundry facilities were communal with proper metering, saved heaps on individual unit installations while meeting all body corporate requirements.
Planning Multi-Unit Electrical
Planning is the most important part. Get it wrong at the start and you pay for it throughout the build.
We work with developers and architects early in the design phase. Look at the building plans, figure out power requirements for each unit, plan shared services, determine main supply needs.
Power company gets involved early too. They need to know total load so they can plan supply. Sometimes they gotta upgrade transformers or run bigger cables to the site. That takes time so dont leave it til last minute.
Meter box location is critical. Needs to be accessible but secure. Usually goes at the front boundary but depends on site layout. We plan for individual meters plus shared services meter.
Cable routes between meter box and units need planning. Underground or overhead? Through common areas or around perimeter? Affects cost and complexity.
Future-proofing makes sense. Running extra conduits now for future EV chargers or additional circuits costs way less than retrofitting later.
Data and communications get planned at same time. Each unit needs phone and internet connections. Common areas might need wifi access points or security system wiring.
Main Supply and Meter Boxes
Main supply setup for multi-unit is different from single houses.
Power comes from the street to a main meter board. This board has individual meters for each unit plus a meter for shared services. Each meter connects to its own switchboard.
Meter boards for multi-unit are big - custom built enclosures that house all the meters. They gotta be weatherproof, secure, and accessible for meter readers.
Some developments use pillar boxes - freestanding cabinets that hold all the meters. Others have meter boards mounted on walls or fences. Depends on site layout and power company requirements.
Each unit gets a main switch at the meter board before going to their individual switchboard. Lets power company or electricians isolate individual units without affecting others.
Cable sizing for main supply is critical. Gotta handle total load of all units plus shared services. Usually heavy gauge cables in conduit from street to meter board.
Earthing system for multi-unit needs careful design. Multiple earth stakes or connection to power company earth. All units bond to common earth system.
Had a 8-unit townhouse development in Halswell where we installed a massive pillar box at the front. Each unit got their own meter, plus one for common area lighting and gates. Power company approved the design before we started so there were no surprises.
Individual Unit Wiring
Each unit gets wired like a house but with some differences.
Switchboard for each unit goes inside that unit. Usually in garage or laundry. Standard circuits - kitchen, bedrooms, bathroom, lighting, heat pump, hot water.
Cable runs from main meter board to unit switchboards through conduit. Underground if going across driveways or gardens, through walls if units are attached.
Smoke alarms in multi-unit developments have to be interconnected. When one goes off they all go off. Wired connection between units for this. Helps people evacuate if fire starts in another unit.
Each unit needs proper RCD protection same as any house. Safety switches on all circuits.
Outlets and lighting get installed once framing is up. Same process as regular houses - rough-in when walls are open, finals after plaster and paint.
Units that share walls need fire-rated electrical penetrations. Special sealing where cables go through fire walls between units.
Shared Services Electrical
Shared services are what makes multi-unit developments different from standalone houses.
Common area lighting - driveways, pathways, letterboxes, entrances. Usually on timers or sensors so they come on at dusk.
Security lighting for parking areas and walkways. Motion sensors that trigger when people approach.
Automatic gates need power for motors and controls. Safety sensors to stop gates if something in the way.
Intercom systems at entry gates or front doors. Let visitors call units, residents can open gates remotely.
Garage door motors for shared garages. Each unit might have their own garage door opener.
Garden irrigation systems that run off timers.
CCTV security cameras covering common areas.
All of this runs off the shared services meter. Body corporate pays the power bill and splits cost between owners usually through levies.
Control systems for shared services need to be accessible but secure. Usually locked cabinets or rooms that only body corporate managers can access.
Fire Safety Requirements
Fire safety is serious business in multi-unit developments cause fire in one unit affects everyone.
Interconnected smoke alarms are required. Photoelectric type, wired together so if one detects smoke they all alarm. Gives everyone warning even if fire is in different unit.
Emergency lighting in common areas and exit paths. Battery-backed lights that stay on if power fails. Help people evacuate safely.
Fire alarm systems in bigger developments - apartments or complexes with many units. Central panel that monitors smoke detectors throughout the building. Often connected to fire service.
Exit signs that are illuminated and have battery backup.
Fire-rated cable penetrations where electrical goes through fire walls. Special sealing that prevents fire spreading through cable holes.
Regular testing and maintenance of fire safety equipment. Often body corporate hires us to do annual checks of smoke alarms, emergency lighting, fire alarm systems.
Did a 12-unit apartment building in Riccarton with full fire alarm system. Smoke detectors in each unit, common areas, stairwells. Heat detectors in garages. All connected to central panel that calls fire brigade automatically if activated. Required by council for building that size.
Data and Communications
Modern multi-unit developments need good data infrastructure.
Each unit gets fiber or copper connections for internet and phone. Usually comes from street to main comms cabinet then distributed to units.
We run CAT6 cable during construction for wired network. Each unit might get outlets in lounge, bedrooms, home office areas.
TV antenna or satellite systems often shared. Single antenna on roof with signal split to all units. Or individual dishes if residents prefer.
WiFi coverage in common areas sometimes. Access points in lobbies, parking areas. Paid for by body corporate.
Intercom wiring connects entry points to individual units. Modern systems use network cables instead of old-school analog wiring.
Security system wiring for cameras and access control. Network cables to each camera location, access control panels at entries.
Smart home pre-wiring if units are marketed as smart-home ready. Network outlets in locations where smart hubs or controllers might go.
Coordination with Other Trades
Multi-unit projects have lots of trades working at once. Coordination is critical.
Builders frame the units. We come in for rough-in before walls close up. Gotta coordinate timing so were not holding up the build.
Plumbers need to run their pipes which sometimes cross our cable routes. We coordinate where cables and pipes go so they dont interfere.
HVAC installers need power for heat pumps and ventilation systems. We install circuits and outlets where they need them.
Plasterers close up walls. We gotta be finished with rough-in before they start or we cant run cables.
Painters do their work. Then we come back for finals - installing outlets, switches, light fixtures.
Regular site meetings help. Builder coordinates all the trades so everyone knows whos doing what when. Prevents delays and conflicts.
Good builders know how to coordinate electrical with other trades. Bad builders dont plan ahead and everyone gets in each others way. Slows the project down and costs more.
Code Compliance and Inspections
Multi-unit developments have stricter compliance requirements than single houses.
Building consent covers all electrical work. Plans have to show meter locations, main supply sizing, unit switchboard layouts, shared services design.
Multiple inspections throughout the build. Rough-in inspection before walls close. Finals inspection once everythings installed. Sometimes additional inspections for fire systems or shared services.
Council inspectors are stricter on multi-unit. They check everything carefully cause mistakes affect multiple families.
Power company inspections for main supply and meter board. They have their own requirements separate from council.
Fire service might inspect fire alarm systems in bigger developments.
Code compliance certificates for each unit. Proves electrical work is compliant and safe. Buyers need these when purchasing units.
As-built documentation showing what was actually installed. Sometimes design changes during construction. As-builts show final configuration.
We handle all the paperwork and inspections. Make sure everything gets signed off properly so there are no issues at sale time.
Common Problems in Multi-Unit Electrical
Seen plenty of problems on multi-unit jobs over the years.
Undersized main supply cause developer didnt plan properly. Gotta upgrade supply mid-build which delays everything and costs heaps.
Meter board in wrong location. Power company wont connect it cause its not accessible or doesnt meet their requirements. Have to relocate it.
Shared services not metered separately. All shared power going through one units meter. That owner gets stuck paying for everyones common area lighting and gates. Creates disputes.
Smoke alarms not interconnected properly. Dont meet fire safety requirements, fails inspection.
Fire-rated penetrations not sealed correctly. Inspector makes you open walls and redo them.
Individual units not properly isolated. Turning off one unit affects others. Poor design.
Cable sizing wrong for load. Breakers trip constantly once people move in cause circuits cant handle actual usage.
Documentation incomplete or wrong. Delays code compliance certificates which holds up sales.
Most of these come from inexperienced electricians or developers trying to save money. Hire proper electricians from the start and avoid these issues.
Cost of Multi-Unit Development Electrical
Multi-unit electrical costs more per unit than standalone houses cause of the shared services and complex setup.
Main supply and meter board - $8,000-15,000 depending on size and whether power company needs to upgrade transformers.
Electrical per unit - $8,000-12,000 for standard 2-3 bedroom townhouse. Similar to standalone house.
Shared services - $5,000-15,000 depending on what shared facilities the development has. Gates, intercoms, security cameras, lighting all add up.
For a typical 6-unit townhouse development total electrical might be $70,000-100,000. Includes everything - main supply, all units, shared services, fire safety, data cabling.
Larger developments with more units bring per-unit costs down cause shared services get split more ways.
Apartment buildings with complex fire systems and central facilities cost more. Could be $15,000-20,000 per unit.
These are rough numbers. Every development is different. We provide detailed quotes once we see plans and know exactly whats involved.
Timeline for Multi-Unit Projects
Multi-unit electrical takes longer than single houses.
Planning and design - 2-4 weeks before construction starts. Working out main supply, getting power company approvals, finalizing designs.
Main supply installation - 1-2 weeks. Installing meter board, running cables from street, coordinating with power company.
Rough-in per unit - 2-3 days each. Can do multiple units at once if enough staff. 6 units might take 2-3 weeks total for rough-in.
Shared services installation - ongoing throughout build. Install as different areas get ready.
Finals per unit - 1-2 days each once units are painted. Again can do multiple at once.
Testing and commissioning - 1 week once everything installed. Test all circuits, smoke alarms, shared services, meters.
Inspections and sign-off - 1-2 weeks waiting for inspectors and sorting any issues they find.
Total timeline for 6-unit development - usually 8-12 weeks from start to code compliance certificates. Depends on how organized the build is and whether other trades stay on schedule.
Working with Developers and Builders
Multi-unit projects are team efforts. Good relationships with developers and builders make everything smoother.
We prefer getting involved early. Help with planning, give input on electrical design, flag potential issues before construction starts.
Clear communication about timelines and requirements. Developers need to know when we need access to site and how long different stages take.
Flexibility when schedules change. Builds rarely go exactly to plan. Weather delays, material shortages, other trades running late. We adjust our schedule to keep the project moving.
Problem-solving when issues come up. Design might not work in reality once construction starts. We work with builders and developers to find solutions.
Budget management. We stick to our quotes unless scope changes. If developer wants changes we discuss cost implications up front.
Quality work that passes inspections first time. Reduces delays and keeps project on track.
Developers who work with us regularly know we deliver. They trust us to handle the electrical properly and keep their projects running smoothly.
Post-Completion Support
Our work doesnt end when units are finished.
Handover documentation for each unit. Electrical plans, test results, compliance certificates. Gets passed to buyers at settlement.
Body corporate gets documentation for shared services. How everything works, maintenance requirements, emergency procedures.
Defects liability period - usually 12 months. If any electrical issues come up during that time we fix them under warranty.
Maintenance contracts for shared services. Body corporates often hire us to maintain common area lighting, gates, fire systems. Regular checks keep everything working.
Additions or modifications after completion. Owners might want extra outlets or circuits. We come back and do that work.
Support for body corporate managers. Answer questions about electrical systems, help them understand bills and requirements.
Townhouses vs Apartments
Townhouses and apartments are different electrically even though theyre both multi-unit.
Townhouses are usually attached houses. Each unit has its own switchboard inside the unit. Simpler setup than apartments.
Apartments have units stacked on top of each other. Switchboards often in shared electrical rooms. Cable runs go vertically through building not just horizontally.
Apartments need more complex fire systems. Bigger buildings mean more fire safety requirements.
Lift electrical in apartment buildings. Requires three-phase power and special controls.
Central hot water in some apartments. Big gas or electric water heaters in plant rooms serving multiple units.
Apartments often have building management systems. Central control of lighting, security, climate. Way more complex than townhouses.
Both types need experienced electricians but apartments are definitely more involved.
Why Use Experienced Electricians
Multi-unit electrical isnt for beginners. Needs electricians who know what theyre doing.
Code requirements are stricter and more complex than houses. Easy to miss requirements if you dont do multi-unit regularly.
Power company regulations for main supply. They have specific requirements that vary by location. Gotta know what theyll approve.
Coordination with other trades and managing timelines. Inexperienced electricians slow down whole project.
Problem solving when issues come up. Developments always have surprises. Need experience to find solutions quickly.
Relationship with inspectors. They know us, trust our work, inspect more efficiently when they know quality will be good.
Understanding body corporate requirements and how developments work long-term. Design decisions affect owners for years.
Like that Rolleston developer learned - saving money on cheap electricians costs way more when work has to be redone. Hire experienced people from the start.