The core purpose of a building enclosure is to be an environmental separator.

A building enclosure has four core functions. In order of importance, they are:

  1. Rain control
  2. Air control
  3. Vapor control
  4. Thermal control (easiest to control and least important)

Energy Efficiency

Formance™ panels combine superior insulation with near-zero air leakage to maximize the performance of the building envelope and allow HVAC systems to operate more effectively. You also get:

  • Reduced energy consumption.
  • Lower energy bills.
  • Up to 90 percent less air leakage than stick-framed structures.
  • No thermal bridging or convection looping.


 Formance™ panels help improve structural strength for resistance to natural disasters. You also get: 

  • Structural characteristics similar to a steel I-Beam. 
  • Superior structural stability with stiffness, strength, and predictable performance. 
  • Lower maintenance requirements.


There's nothing quite like the feeling that you're doing your bit. Formance™ panels are a welcome relief to our environment, having an estimated reduction in the level of Carbon emissions of 9.9 x over the life of the building when compared to traditional building methods. Key contributors to the superior performance of Formance™ panels in this area include:

  • Reduced heating and cooling loads over lifetime of home
  • High R-value
  • Low air leakage rate
  • Low environmental impact of materials
  • Low maintenance requirements
  • Lightweight materials reduce transportation

Design Freedom

Rounded roofs, arched windows and other complex designs are made simple with Formance™ panels. The manufacturing process means that no design element is too hard to accomplish. You also get:

  • Ability to cut almost any shape
  • Open and airy feel with no need for false ceilings
  • Ability to maximize  space


Formance panels are engineered in a controlled factory environment meaning precision home building is now a reality for builders. Easy to build with, fast to erect and with less wastage or re-work on site, Formance panels put the satisfaction back into a job well done for builders.

We want to start a new conversation about the effectiveness of the function of the building envelope and share information about the proven and certified alternatives to the traditional timber frame and insulation type of building. 

What are SIPs?

SIPs are high performance thermally efficient composite panels which consist of a sandwich of two layers of structural board with an insulating layer of foam in between for walls, roofs and floors in new residential and commercial buildings.

Structural Insulated Panels (SIPs) are a widely used alternative construction material for homes and other buildings, with a proven record for over 40 years in the US, Europe and the UK. While many types of Composite Panel building systems have been developed, SIPs now usually refers to panels made from a thick layer of foam (polystyrene or polyurethane) sandwiched between two layers of Oriented Strand Board (OSB). The result is an engineered panel that provides structural framing, insulation, and exterior sheathing in a solid, one-piece component. Formance™ panels are not only true to the well known and proven SIPs design, they also have Codemark certification which ensures compliance with the NZ Building Code and gives peace of mind that Formance™ panels will meet the standards and deliver a high performance building.

The basic design concept for Formance™ panels is elegant in its simplicity, and offers several advantages for constructing walls and roofs. Bonding the foam core to the stiff outer skins creates a web-and-flange structural strength (along the same principal as an I-beam) across the length and breadth of the panel. With the capacity to handle axial, bending, racking, and shear loads, properly designed and assembled Formance™ panels not only replace conventional framing, but will withstand high wind, and seismic forces. So what are the benefits?

SIPs vs Sticks

Formance vs Framing

Green Building with SIPs

Firstly, what exactly is Green Building?

Green building is the practice of minimizing the impact a building has on the natural environment. Although there are numerous theories and rating systems proposing how this can be accomplished, they all share several clear goals:

  1. Reduced Energy Consumption - Energy is in high demand, and the processes used to generate energy often produce carbon dioxide emissions. Decreasing energy and fossil fuel use in buildings is important to prevent large-scale climate change.
  2. Material and Resource Conservation - Green designers and builders select building materials and methods that reduce the amount of natural resources required to construct a building.
  3. Healthy Indoor Environment - With people spending 90% of their time indoors, buildings should create a safe environment for occupants, free from mold, volatile organic compounds (VOCs) or other harmful airborne pollutants.
  4. Water Conservation - Water-saving systems limit the use of this important natural resource and prevent water pollution that can damage natural ecosystems.
  5. Site Planning - Careful site and infrastructure development will minimize water and air pollution. 

Structural insulated panels (SIPs) are one of the most airtight and well insulated building systems available, making them an inherently green product. An airtight SIP building will use less energy to heat and cool, allow for better control over indoor environmental conditions, and reduce construction waste. 

R Values

Formance™ panels come in various standard thicknesses and associated R values. For

Size of total panel (mm)

EPS Thickness R Value Width (mm) Standard Lengths (mm)
115 93 2.8 1220

2740, 3050, 7315

165 143 4.3 1220

2740, 3050, 7315

215 193 5.7 1220

2740, 3050, 7315

265 243 7.2 1220

2740, 3050, 7315

315 293 8.6 1220

2740, 3050, 7315

What you need to know about Moisture Control in the building envelope

Moisture is the enemy of durability so having an effective moisture control system is essential for a long lasting home. Dr Joe Lstiburek, Building Science guru, states that 80% of construction problems are related to water.

Contrary to traditional wisdom in the NZ construction industry today, a rigid air barrier on the outside of the external frame is not a good idea from a moisture control perspective.  In most areas of NZ at most times of year, the inside of the home is warmer than the outside; this generates a gentle positive pressure from the inside of the building to the outside. If the inside is not airtight, any moisture in the air is carried through the wall assembly towards the outside. When it arrives at the outside of the building and meets the cold surfaces it can condense and cause durability issues. That is if the outside is also sealed. Most rigid air-barriers are required to be sealed - we call them a sweat jacket. In a nutshell this is the issue that councils are facing in the colder South Island - durability issues from poor control of internal moisture.

The solution is two fold and beautifully dealt with by Formance panels.

  1. We ensure the inside of the panels is sealed - we do this with tape (if the walls are to have an additional lining) or silicone (if the walls are to be the finished surface).

  2. Ensure the outside of the panels are not sealed - so no taping or self-adhesive wraps on the outside to seal moisture in. 

This means that the building will last forever - internal moisture is prevented from entering the structure and external moisture that beats the weather-tight system (cladding) will be allowed to escape through the unsealed external. This includes any moisture picked up during construction.