John Street Development

Project Summary

Main Contractor: Mary Lou Developments

Blackwell Plumbing and Gas has been contracted by Mary Lou Development to carry out the plumbing services for a six-unit residential development at 33 John Street. This project involves completing the full plumbing installation across all six townhouses, from the underslab drainage through to the final fixture installation and commissioning.

As one of the first trades on site, our work is essential in allowing the build to progress. By working closely with Mary Lou Developments and coordinating with other subcontractors, we are helping bring six modern homes to life.

Scope of Works

• Install underslab sewer drainage to serve all ground floor fixtures.

• Install hot and cold-water services to all plumbing fixtures using Rifeng PEX pipework.

• Install suspended sewer drainage to serve all first-floor fixtures.

• Install floor wastes to wet areas within the conjoined units.

• Install plumbing fixtures and fittings.

• Complete testing and commissioning of all plumbing systems.

• Provide as-built drawings and producer statements.

Challenges & Approach

Delivering plumbing services across a multi-unit development requires careful planning and collaboration. Each townhouse must be completed on schedule while ensuring all underground services align with the building layout and future construction stages.

Our team approached the project strategically, beginning with the set-out of the underslab drainage before progressing through installation and backfilling. Throughout the project, close communication between our team and Mary Lou ensured each stage was completed efficiently and inspections were passed without delaying the overall construction schedule.

The underslab stage is one of the most important phases of the build, as much of the plumbing infrastructure will be permanently concealed once the concrete slab is poured. Taking the time to complete each installation accurately and pass all required inspections ensures the homes are built on a reliable plumbing system from day one.

Current Progress

The project has progressed well through the early construction stages, with the underslab drainage successfully completed across all six units. Sewer drainage, stacks, gullies, floor wastes and associated pipework have been installed, inspected and approved before being backfilled and prepared for slab construction.

Floor wastes have been installed in the conjoined units, allowing internal works to continue as the buildings progress. As construction continues, Blackwell Plumbing and Gas will complete the remaining plumbing installations, including hot and cold water services, suspended drainage, hot water cylinder installations and fixture fit-off. We look forward to seeing the John Street development evolve into six quality homes that will serve the community for years to come.

Whitemans Road Development

Project Summary

Main Contractor: GS Homes

Blackwell Plumbing and Gas has been contracted by GS Homes to deliver the plumbing and drainage services for a nine-unit residential development at 41 Whitemans Road. This project forms part of a new housing development and involves completing all underground plumbing and drainage infrastructure, water services and plumbing installations for each unit.

Working closely with GS Homes and other trades, our team is ensuring the project progresses efficiently while maintaining a high standard of workmanship. As one of the first trades on site, our work lays the foundation for every stage of construction that follows.

Scope of Works

• Install underslab sewer drainage connecting to the civil contractor's laterals.

• Install underslab stormwater drainage to all downpipes and sumps.

• Supply and install in-slab Aquacomb water tanks for all nine units.

• Install hot and cold water services to all plumbing fixtures.

• Install internal sewer stacks to each dwelling.

• Install customer-supplied plumbing fixtures and fittings.

• Install all traps, wastes and valves.

• Complete testing and commissioning of all plumbing systems.

• Provide as-built drawings and producer statements.

Challenges & Approach

Large multi-unit developments require careful planning and coordination between multiple contractors working simultaneously. Before any pipework could be installed, each slab required accurate set-out and excavation to ensure all drainage aligned with the building plans and civil infrastructure.

To keep the project moving, our team is working systematically through each unit, completing excavation, drainage installation and backfilling before progressing to the next stage. Regular communication between our team, GS Homes and council inspectors has allowed inspections to be completed promptly, reducing downtime and maintaining momentum.

Attention to detail is an important part of every job we complete. It is particularly important throughout the underslab phase, as any issues discovered after concrete is poured become significantly more difficult and costly to rectify. Every drainage system has therefore been carefully inspected before being approved for backfilling and slab pouring.

This project is helping create nine new homes for the community. Every trench excavated, drain installed  and inspection passed brings these homes one step closer to welcoming their future owners.

Current Progress

The project has made excellent progress through the early construction stages. To date, our team has successfully completed the underslab drainage for multiple units, including excavation, drainage installation, council inspections and backfilling.

Excavation has included installing sewer and stormwater pipework, drainage stacks, gullies, downpipe connections, hot water cylinder locations and Aquacomb outlets. Following successful inspections, the trenches have been backfilled, compacted and prepared for slab pouring, allowing the GS Homes to continue with the next phase of the build.

As construction progresses, Blackwell Plumbing and Gas will continue delivering the plumbing and drainage installations across all nine units, working collaboratively with GS Homes to deliver a high-quality development that will provide modern, reliable homes for years to come.

Flood Restoration

Project Summary

Main Contractor: Prier & Associates Managment

Following the severe weather events that impacted Wellington in March, many families were left with damaged homes that required extensive repairs before they could safely return to normal life. Blackwell Plumbing and Gas was engaged by Prier & Associates Management to support the region's recovery, providing plumbing services across a range of insurance reinstatement projects.

Working alongside builders, insurers and homeowners, our team is in the process of completing more than 30 insurance-related jobs, helping restore essential plumbing services and supporting families as they returned to safe, comfortable homes. Every project represented more than just repairing plumbing, it was about helping people rebuild after an incredibly difficult time.

Scope of Works

• Disconnect plumbing fixtures prior to demolition and building repairs.

• Isolate and protect existing plumbing services throughout the restoration process.

• Reinstall toilets, vanities, tapware and other plumbing fixtures following building works.

• Test and commission all plumbing installations to ensure they were safe and fully operational.

• Coordinate with builders, project managers, insurers and homeowners to support the efficient delivery of each project.

Challenges & Approach

No two properties were the same. Each home had experienced different levels of damage, with restoration works progressing on varying schedules and multiple trades working together to return each property to a liveable condition.

Our role required flexibility, clear communication and close collaboration with Prier & Associates Management, builders and homeowners. Plumbing fixtures were carefully disconnected before demolition and reinstated once repairs had been completed, ensuring work could progress safely while minimising delays.

Throughout the project, we understood that behind every job was a family waiting to move back into their home. By adapting to changing schedules, maintaining high workmanship standards and communicating closely with everyone involved, we helped keep each restoration moving forward and reduced the time homeowners were displaced.

Outcome

Blackwell Plumbing and Gas has successfully completed multiple reinstatement projects with many more to come as part of Wellington's severe weather recovery, helping restore homes for families across the region.

By working collaboratively with Prier & Associates Management and other contractors, we have ensured plumbing systems were safely reinstated, allowing homeowners to return to functional, comfortable homes with confidence. While our work focused on plumbing, the outcome was much bigger, supporting Wellington's recovery one home at a time.

These projects reflect our commitment to quality workmanship, reliability and being there for our community when it matters most.

Esk Place WIP

Project Summary

Main Contractor: Miles Construction

Blackwell Plumbing and Gas has commenced work on the Esk Place development in Cannons Creek, contracted by Miles Construction. This project will deliver ten new two-storey homes for Kāinga Ora, providing quality housing for the local community.

Our role at this stage of the works is to complete the underground plumbing and drainage infrastructure that will support the development from the ground up. As one of the first trades on site, careful planning, coordination and teamwork are essential to keep the project progressing efficiently.

Scope of Works

• Excavate trenches for the underslab drainage and plumbing services.

• Install all underslab drainage and plumbing pipework.

• Install drainage stacks.

• Backfill all drainage trenches.

• Coordinate works with the main contractor and other subcontractors to maintain project progress.

• Prepare the site for the next stages of construction.

• Return to complete the plumbing first fix and fit off as well as test and commission.

Challenges & Approach

Commencing the project during winter presented the biggest challenge. Heavy rainfall, low temperatures and saturated ground conditions affected excavation works and, on some days, made it unsafe to continue working. As underslab drainage is highly dependent on weather conditions, flexibility and effective planning were critical to maintaining progress.

Working closely with Miles Construction, our team adapted the programme to suit changing site conditions while ensuring work was completed safely and efficiently. Effective scheduling allowed resources to be redirected when required, minimising delays and keeping the project moving forward.

As with any active construction site, multiple trades and heavy machinery were operating simultaneously. Clear communication, cooperation and a strong focus on health and safety enabled all contractors to work together safely while maintaining productivity.

Outcome

Despite the challenging winter conditions, the excavation, underslab drainage, plumbing pipework and drainage stacks were successfully completed, with all trenches backfilled and prepared for the next stage of construction.

The project remains on schedule, providing a solid foundation for the construction of the ten new Kāinga Ora homes. Through effective planning, teamwork and collaboration with Miles Construction and other subcontractors, Blackwell Plumbing and Gas has continued to deliver quality work while maintaining a safe and efficient work environment.

We are looking forward to returning to complete the plumbing first fix and fit off at Esk Place.

Sink Hole turned Redundant Sewer Chamber

Project Summary

What started as a small sinkhole quickly turned into an investigation beneath the surface.

The customer contacted Blackwell Plumbing after noticing a small hole had appeared in the ground. While the opening itself was unremarkable, an initial inspection told a different story, a large underground void was hiding just below. Peering down into the cavity, we could make out the shape of concrete structures, and the questions started piling up. Was it an old concrete chamber? Some kind of hidden room? With no clear answers in sight, the mystery only deepened.

Approach

Our first instinct was to start excavating and get to the bottom of it. However, once we'd assessed the size of the void and the risks involved, it was clear this needed engineering input before any digging could go ahead. The customer got in contact with geotechnical engineer Nick and building consultant Sandeep, and together we worked out a safe, practical way to uncover what had caused the collapse.

Before digging into the void, we dug into historical records, but they offered little help. There were no known stormwater connections in the area, and no drainage plans on file that could explain a structure like this beneath the ground. For a while, the cavity stayed exactly that, a mystery. Were we about to find an abandoned underground bunker?

With a plan now in place, excavation got underway. Sam carefully operated the excavator while Teddy acted as spotter, guiding him throughout the dig. As we uncovered this mystery chamber, we found it had been closed using railway sleepers. Over the decades, the timber had deteriorated and rotted away, eventually losing its strength and its ability to hold up the soil above. That's what caused the ground to give way, creating the sinkhole that first caught the customers attention. This concrete chamber could be 5m long or 500m… Time to get Leslie Drain Clearing in and see how far this goes.

The Breakthrough

The breakthrough finally came when we found plans from 1953 that showed over 70 years ago, a septic chamber had existed in that exact spot. Simultaneously, Leslie’s Drainclearing had found the end of the chamber. So, we brought in the big guns, a 5-tonne digger. Sam took the controls, carefully clearing the remaining material and removing the deteriorated railway sleepers until the chamber was fully exposed.

Closing it up!

Once the void had been completely uncovered and assessed, it was permanently filled using metal and dirt, topped with topsoil and grass seed. The result was a safe, stable surface restored to its original condition, as if the hidden chamber had never existed at all.

This project was a great reminder that even the smallest signs on the surface can be hiding something much bigger below. Through collaboration, investigation, and careful excavation, the mystery beneath the ground was solved, and the site was safely restored for future generations of students.

Acknowledgements

Thank you to Nick Clendon, Sandeep Patel, Leslie Drain Clearing and the Customer. Everyone involved made this process run as smooth as possible. Blackwell Plumbing would like to thank the customer for their cooperation throughout the project and our dedicated team for their hard work and expertise in safely investigating and repairing the underground void. It was a great example of teamwork, problem-solving, and delivering a safe outcome for the community.

29/06/2026 Victoria Stowers

Te Pukenga

Project Summary

Blackwell Plumbing and Gas was engaged by a main building contractor to carry out decant works for a commercial tenancy in the Wellington CBD. The project involved the disconnection and removal of existing plumbing and gas services followed by the installation of new systems to support the incoming tenancy.

Working within a live CBD environment, the project required careful coordination to minimise disruption to surrounding tenants with active businesses operating nearby, including a cooking school directly below. Our team adapted scheduling and carried out a significant portion of the work after hours to ensure continuity for other occupants.

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Scope of Work

• Disconnection and capping of existing drainage and waste systems

• Removal of gas services servicing levels three and four

• Disconnection of existing hot and cold-water services

• Installation of new cold water connection including meter and isolation valves

• New cold-water mains installed to service levels 3 and 4

• Installation of new water supply to accessible bathroom facilities

• Supply and installation of new hot water cylinder

• Fit-off of accessible bathroom fixtures and fittings

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Challenges and Approach

Operating within an occupied CBD building presented logistical challenges particularly with neighbouring tenancies continuing daily operations. Noise restrictions and limited access to water shutdown periods required careful planning and communication. Working within existing structures also meant much of the work was carried out behind closed walls, with the scope evolving as areas were opened up. This required our team to remain flexible and respond quickly to changing conditions throughout the project. The project also involved the removal of heavy materials, with work carried out at height in a central city environment. Limited access and space constraints made waste management more complex requiring a practical and well-coordinated solution.

Blackwell Plumbing and Gas took the lead in developing a waste management approach engaging Bolt Bins to implement a flexible solution that allowed material removal to be handled efficiently. Critical works were scheduled after hours where required allowing the project to progress smoothly while minimising disruption to surrounding tenants.

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Outcome

The project was delivered efficiently with all services safely disconnected and new systems installed to meet the requirements of the incoming tenancy. Through proactive communication and flexible scheduling, Blackwell Plumbing and Gas was able to complete the works with minimal impact on surrounding businesses. The result was a clean, compliant and well executed plumbing solution ready for the next stage of the building's use.