Piha House

12 hours ago
2 min read

Products Used: Nuraply 3PM, Flat Enertherm PIR, Nuralite Fixing plates

Situation

The Piha House project, completed in 2022, is a high-performance residential retrofit designed by Sang Architects and developed by Terry Bryers. The project was reimagined around Passive House principles to deliver exceptional thermal efficiency, durability, and occupant wellbeing.

The building envelope incorporates high-performance windows with double glazing and a fully insulated warm roof system, utilising Nuralite’s Nuraply 3PM membrane over Flat Enertherm PIR insulation, along with Nuralite fixing plates. Purpose-designed fixings were integrated to support photovoltaic solar panels, while complementary systems contributed to a continuous, high-performing thermal envelope.

Challenge

Following the discovery of significant mould contamination within the wall cavities and roof space, the project scope expanded from a renovation into a full Passive House retrofit. The building was stripped back to its core concrete structure and timber framing, with all retained elements treated and sealed to eliminate mould risk.

A key challenge was addressing thermal bridging within the existing concrete structure, particularly at terraces and mid-floor slabs. Achieving continuity of insulation and airtightness across complex junctions, such as interfaces between concrete, timber, and structural steel, required careful detailing.

Additional complexity arose from penetrations through the thermal envelope, including exposed timber elements and service interfaces, which risked compromising airtightness. Working within an existing concrete structure also created construction challenges, particularly when integrating new systems and managing penetrations.

Solution

A comprehensive approach was implemented to deliver a continuous, high-performance building envelope. The underside of the terrace concrete slabs was insulated and sealed and structural penetrations were carefully wrapped to reduce thermal bridging and prevent internal condensation.

A continuous airtightness layer was established beneath the ceiling structure, with complex penetrations and exposed elements sealed to maintain envelope integrity.

The warm roof system, featuring Nuralite’s Nuraply 3PM membrane over Flat Enertherm PIR insulation, provided robust waterproofing and thermal performance, while accommodating integrated solar PV and thermal panel fixings.

The result is a highly durable, energy-efficient building envelope that meets rigorous Passive House standards. The Piha House became the first certified Passive House EnerPHit project in New Zealand, setting a benchmark for high-performance residential retrofits.

Registered Master Builders Award 2022 - Regional Supreme Renovation of the Year

Registered Master Builders, House of the Year Award 2022 - National APL Sustainable & Environmental Excellence Award.

27th May 2026