Grantham Group team standing in a parking lot with vehicles, including a small excavator in the center, under a cloudy sky.

Grantham Group is one of New Zealand’s most experienced plumbing and drainage companies, with over 30 years of proven delivery across both residential and commercial projects. What began in 1991 as South Auckland Plumbing, a small six-person team focused on residential maintenance, has grown into a group of more than 35 full-time professionals delivering projects of every scale.

From Small Beginnings to Industry Leaders

Over 30 Years

Through steady expansion and a reputation for reliability, South Auckland Plumbing built a strong presence in both residential and commercial markets. To meet growing demand for large-scale projects, Grantham Plumbing & Drainage was established. A specialist division focused on complex commercial builds, high-end residential developments, and new construction across the wider North Island.

Today, South Auckland Plumbing continues to deliver trusted service and maintenance solutions for commercial, industrial, and residential clients, while Grantham Plumbing & Drainage leads delivery on state-of-the-art hotels, multi-level apartments, schools, healthcare facilities, and major retail projects. In 2024 alone, Grantham delivered plumbing for three new hotels, with further projects now underway in Wellington.

Still Building Strong.

Across every division, Grantham Group is defined by family values, technical excellence, and an unwavering commitment to quality, safety, and innovation. Our reputation has been built on more than three decades of proven performance, and we continue to grow with the same principles that have driven us since day one: honesty, loyalty, fairness, and delivering solutions clients can depend on.

Meet the team

Kevin Grantham
Director

kevin@granthamgroup.co.nz
09 263 7621
021 915 337

Minal Patel
Plumbing Estimator / Quantity Surveyor

minal@granthamgroup.co.nz
09 263 7621

Thomas Tai
Drainage Estimator / Quantity Surveyor

thomas@granthamgroup.co.nz
09 263 7621

Grantham Group team of people standing in front of service vehicles on a gravel surface with a cloudy sky overhead.

Residential Team

Ruby
Plumbing Estimator / Quantity Surveyor

rubyl@granthamgroup.co.nz
09 263 7621

Grantham Group team of workers standing outdoors in front of utility vehicles and construction equipment. The sky is cloudy and the background features green fields.

Commercial Team

Excavator demolishing large rocks at dusk, with trees in the background.

Positive Practices

Green cross symbol on a black background.

Positive impact through Safety, Wellbeing and Sustainability.

Grantham Group is committed to achieving positive outcomes for our team, clients, and the environment.

Our focus on safety, wellbeing, and sustainable practices ensures that every project is delivered responsibly, efficiently, and with long-term benefits for all stakeholders.

Grantham Group’s approach ensures that positive practices today create lasting positive impact for our people, our clients, and the wider community.

Current Practice

Supported by robust H&S systems including Hammertech, BrightSafe, and Sign On Site, our culture prioritises wellbeing, inclusion, professional growth, and the health of every team member.