Right in the heart of Wellington sits Kelvin House - an 8-storey residential building with a distinctive character and a few complex challenges to match. At first glance, it’s a typical top-floor remediation project. But dig a little deeper, and it becomes a story of smart problem-solving, deep collaboration, and a commitment to doing things right.
This project focused on the penthouse units on the top two levels, where the goal was to fix persistent weathertightness issues, boost thermal performance, and improve seismic resilience, all while preserving the building’s protected heritage façade.
At a glance
Address: 16 The Terrace, Wellington
Type of project: Remediation
Status of project: Complete in June 2025
Client: Body Corporate. Managed by Property Consultants (NZ) Ltd
Architect: Inside Design Ltd
Oculus rep: Glenda Yee | glenda@obfs.co
The Vision and Our Role
The client’s vision was centred on preserving the essence of the original building - retaining its unique plaster detailing and reusing the striking two storey windows that had become part of its identity.
Oculus was engaged to support that vision with:
- A thorough investigation into whether the existing windows could be refurbished
- PS1 design services
- PS4 construction monitoring
Through detailed assessment and on-site testing, we confirmed that the 20-year-old windows could meet performance requirements if carefully refurbished and reinstalled. That insight helped shape the design and construction strategy from the outset.
Results and Achievements
The result? A standout transformation of the top-floor penthouses - both in appearance and performance. Key outcomes included:
- A new StoVentec externally insulated rainscreen cladding system
- A warm roof assembly to improve thermal efficiency and control condensation risks
- New balcony membranes to resolve longstanding water ingress issues
- Successful refurbishment and reinstallation of two-storey high windows, complete with original IGUs intact
The project delivered significant improvements in weathertightness, thermal performance, and structural integrity, helping the building meet a higher NBS rating without compromising its heritage features.
Teamwork in Action
This project was a masterclass in collaborative problem-solving, which was essential for de-risking the complexities of re-using the 20-year-old windows.
A key partnership with All Facade Services Ltd helped shape the remediation scope and provide a detailed guide for installers, ensuring work could proceed confidently and consistently.
For some of the more complex junctions, the project team took a hands-on approach - building mock-ups to test, iterate, and agree on a final solution before rolling it out across the building. This proactive process helped de-risk construction and keep momentum steady.
Recognising Excellence
A special thanks to the full delivery team, whose craft and care were instrumental in bringing this vision to life.
- STS Contracting deserve recognition for their exceptional plastering work and attention to detail throughout the cladding phase.
- Glass Group navigated the challenging window removal and reinstall with real precision - handling massive IGUs at height without compromising safety or quality.
- And to our supplier partners, Sto and Ardex, thank you for your continued support - from technical input during design through to practical guidance during construction mock-ups.
Architect: Inside Design Ltd
Engineers / Consultants: NZ Consulting Engineers Ltd & All Facade Services Ltd
Construction: Cemac
Supplier / Installer: Sto New Zealand, Ardex, STS Contracting & Glass Group Ltd
Let's Find the Right Solution for Your Building
Do you need expert investigation, PS1 design, or construction monitoring for a remediation project? The success at Kelvin House showcases our commitment to high performance, resilient solutions.
Let us help you de-risk your project and achieve the right outcome for your building. Contact us at info@obsf.co or get in touch with our team.
