About R-Value Insulation Co

Built on construction and development expertise. Built on integrity.

Reliable Partners. Proven systems. Built on trust.

Our story

From property development to specialist insulation.

R-Value Insulation Co was built on a foundation of construction and development expertise. Our directors began in property development, gaining hands-on experience across every facet of building in the New Zealand market.

Ian has been developing property in New Zealand for over 35 years. His passion for building and eye for detail were passed on to James, who shares the same commitment to quality and craftsmanship. Together, they delivered The Logan Apartments in Epsom, a six-storey, 41-unit in-situ concrete development completed in 2024, during one of the most challenging construction periods in recent memory.

Our team brings firsthand experience managing construction budgets, contracts, and code compliance. We've worked closely with councils, consultants, and contractors, navigating the realities of complex builds while maintaining clear documentation and oversight.

We understand the importance of the construction programme, and the ripple effects of missing key dates. Delays in one trade affect the entire sequence, impacting handovers, financing, and client relationships. That's why we show up prepared, coordinated, and ready to execute, not just for our scope, but in support of the wider project timeline.

Prior to our rebrand to R-Value Insulation Co in 2025, we operated as ASNI and built a strong track record across Auckland, including work for Microsoft NZ, 1 Queen Street, the Pullman Hotel, and a long roster of education, medical, hospitality, and residential builds. The rebrand reflects our focus on performance, compliance, and long-term value.

Directors

James and Ian Guilford.

Father-and-son property developers, now subcontractors. They delivered The Logan Apartments together in 2024. The building our office now sits in.

James Guilford
Managing Director
“We rebranded this business to reflect the belief that builders and developers deserve insulation contractors who show up on time, communicate clearly, and genuinely care about the outcome. With a background in both construction and development management, I've built R-Value to be a company that takes pride in its people, its projects, and its performance.”
Conjoint commerce and property degree from the University of Auckland. Background in property valuation, quantity surveying, development finance, development management, construction contracts, sales and marketing. Hands-on site experience across traffic management, joinery, insulation, and general labour.
Ian Guilford
Director
“Director and business partner to James. I bring 35 years of New Zealand property development experience across city-centre developments, land subdivisions, high-spec architectural homes, multi-unit townhouse projects, office-to-residential conversions, and suburban apartment complexes. I hold the team to a high standard with clear expectations and firm boundaries.”
Over three decades developing across Auckland and beyond. Independent property-development portfolio runs in parallel through Heartland Developments.

Core values

Five values we hold every job to.

Reliability
We turn up on time, deliver as promised, and stand by our work. Clients rely on us because we follow through.
Practicality
Every decision we make is grounded in buildability, cost-efficiency, and long-term performance. We understand the site environment and work with it, not against it.
Integrity
We believe in doing things right, even when no one's watching. From quoting to compliance, we keep things clear, honest, and fair.
Responsiveness
Timelines shift. Problems arise. We stay agile, respond quickly, and communicate early, because that's what keeps projects moving.
Excellence
We aim higher than minimum code. Our installs are tidy, our communication is clear, and our teams are trained to deliver quality on every job.

The 7-point guarantee

Insulation done properly, backed end-to-end.

At R-Value Insulation, we back our work with a 5-Year Workmanship Guarantee and a commitment to clear communication, code compliance, and exceptional service from start to finish. This means you can trust us to get the job done right, with zero surprises and complete peace of mind.

01
Five-year guarantee on workmanship
We stand by the quality of our installs. Every job is backed by a full 5-year workmanship guarantee, giving you confidence in long-term performance.
02
Code-compliant, inspection-ready installs
Our installs are done to the highest standard: clean, accurate, and ready for council inspections without the need for call-backs or rework.
03
Transparent communication
We keep you informed throughout the project. From pre-start to completion, you'll always know where things are at and what's coming next.
04
Accurate quoting, no surprises
Scope clarity matters. We provide clear, detailed quotes, so there are no unexpected extras or scope disputes down the track.
05
Quality products only
We only use proven insulation systems from trusted suppliers like Autex, Pink Batts, Kingspan, Earthwool, and GreenStuf. No cut corners or cheap substitutes.
06
Professional and reliable team
Our installers are experienced, background-checked professionals who take pride in their work and respect your site at all times.
07
Clean and tidy finish
We leave your site as we found it. No loose batts, offcuts, or mess. Clean presentation is part of the job.

Sustainability

Active in the GreenStuf Take Back Programme

Energy efficiency begins with thoughtful construction choices. Insulation plays a pivotal role, and we're committed to delivering solutions that perform exceptionally and minimise environmental impact.

We're proud to partner with Autex and actively participate in the GreenStuf Take Back Programme, a recycling initiative that diverts uncontaminated insulation offcuts and packaging from landfill. Returned material is reprocessed into new insulation products, closing the loop on construction waste.

Autex GreenStuf contains a minimum of 60% recycled polyester fibre (some lines up to 80%) and is manufactured under a zero-waste policy. Recycled GreenStuf is also available as 'reclaimed' for projects looking for an extra sustainability boost.

Uncontaminated GreenStuf offcuts collected in a GreenStuf bag as we go. No waste floating around site.
GreenStuf waste returned to Autex for recycling.
The loop closes: GreenStuf waste becomes more GreenStuf.

Clients & suppliers

Long-term partnerships with builders, developers, and manufacturers.

R-Value Insulation Co is proud to have worked with leading construction companies, developers, fit-out contractors, and product manufacturers across the North Island. Long-term relationships are built on consistency, clear communication, and a reputation for doing things properly.