Structural insulated panels (sip's)

High-performance building system for residential and light commercial construction:

FAQ'S

Here are some frequently asked questions about SIP’s:

What are SIPs (Structural Insulated Panels)?

SIPs stands for Structural Insulated Panel. They are a high performance building system for residential and light commercial construction. The panels consist of an insulating foam core sandwiched between two structural facings, in our case Oriented Strand Board (OSB).

They are often called SIP Panels, which while technically incorrect (you are really saying “Structural Insulated Panels Panels”), is something we find ourselves saying a  bit too!

SIPs are manufactured under factory controlled conditions and can be fabricated to fit nearly any building design. Being custom-made any engineered timber or steel solution can be accommodated.

The result is a building system that is very strong, energy efficient, healthy and warm.

Why did Solace Homes choose to offer a SIPs Alternative?

John Jarvis, who is one of the founders of Solace Homes, has always been a leader in building innovation. He was specifying Insulated corners and intersections of exterior walls 10 years before it was mandatory. He has always specified higher insulation values in his houses. (and they number hundreds!!) He has built solar chimneys into houses and always designed houses around passive solar principles.  Its one thing to get the heat into the house, its another to keep it there. When he saw all the inherent values of the SIP method of construction it made instant sense. Couple this with all his knowledge on passive solar gain and Solace Homes along with Warmer Dryer Living was born.

Does the Formance SIPs system require additional engineering?

No, Formance homes do not require additional engineering input (and cost) unless the design is outside of the scope of the Design Guide. The Design Guide is pre-engineered.

Do Formance SIPs restrict my cladding options?

No, not at all. You can clad your Solace home in whatever cladding you like, subject to it meeting the requirements of the New Zealand Building Code. All SIPs require a cavity system to ensure full compliance with E2 of the code.

No. The Formance System is a complete pre-engineered system certified for compliance with the New Zealand Building Code under the Codemark scheme. Designs must comply with the Formance Design Guide. Designs are submitted along with a copy of the guide and the designer’s checklist found within the guide. 

There have been many Formance projects consented throughout New Zealand. Formance projects have been through all major councils and most of the regional councils as well so you can specify Formance SIPs with confidence.

What effect do Formance SIPs have on indoor air quality?

The beauty of a Formance SIP home is that it’s very airtight; allowing you to have optimum control over the inside environment. The answer is to mechanically ventilate the building with a heat recovery ventilation system. These units are very simple, they simply take the energy from the warm stale air from inside the house and give it to the cooler air coming into the house – at about 80% efficiency. They run 24/7 and can use less power to run than a standard 100W light bulb. Super healthy filtered air comes in, and the inside environment stays warm and dry for the ultimate healthy home.

Controlled ventilation filters out contaminants and allergens, also allowing incoming air to be dehumidified, reducing the possibility for mould growth. There are a variety of ventilation strategies that can be employed to provide fresh air to airtight homes. These vary by climate, but most are relatively inexpensive and operate on automatic control systems without the need for homeowner action.

Why is air tightness so important?

The building science expert John Straube from the University of Waterloo in the USA answers this question like this: “Stopping air is the second-most-important job of a building enclosure. Next to rain, air leaks through walls, roofs, and floors can have the most damaging effect on the durability of a house. Uncontrolled airflow through the shell not only carries moisture into framing cavities, causing mould and rot, but it also can account for a huge portion of a home’s energy use and can cause indoor-air-quality problems.”

How long does it take to install a SIP house compared to conventional framing?

The pre-cut SIP panels are cut and supplied according to shop drawings – it’s like a big jigsaw puzzle – so SIPs are slightly faster. The actual panel erection vs frame erection speed will be about the same, but there is no straightening required (1-3 days depending on the size of the building), and the overall program saving is significant because the internal trades can get into the building and begin their work as soon as the SIPs are standing. They don’t have to wait until the cladding is installed. A study made by RS Means in the USA in 2007 is useful and showed a labour saving of around 50% when comparing SIPs to site framing. However this study is often inaccurately quoted in NZ to prove the speed advantage of SIPs. In NZ we rarely build stick houses by site framing, instead, we use pre-nailed frames and trusses. The real benefits of SIPs are not so much in the time savings as in the energy savings.

The Formance process involves producing shop drawings from which we cut the panels. It means the windows can be ordered to match the openings shown on the shop drawings reducing the wait time for windows to arrive.

What is the best way to run services through SIPs?

We have standard holes in the EPS, 1 vertically in the centre of the panel, and two horizontally, usually at 250mm and 1000mm from the bottom of the panel. Electricians use flexible fibreglass rod to run the cables through. We also use plasticiser-resistant (purple coloured) sheathing on the electrical cable.

Plumbing is a little different, we recommend that this is put on internal framing walls where possible, and not through the EPS core.

How do Formance SIPs costs compare?

Formance SIPs can be as cost-effective as conventional building methods when the panel layout and utilisation are considered in the design phase of the building. We are very happy to provide a no-obligation budget estimate for your plan. Send it here sales@solacehomes.co.nz

While it is hard to do an apples for apples comparison, a material cost similarity is almost identical with 140mm stick framing that has R3.6 batts and a RAB. The main difference between SIPs and the 140mm framing solution is the ongoing high performance from the SIPs. SIPs will be performing as well in 20,30,40 plus years as when it was first installed. The framed house will not only have lost its thermal performance through slumping batts and the inherent air currents (it never performed as well in the from the beginning) as well as this when you factor in labour costs and ongoing reduction in energy usage, the savings using Formance SIPs make the financial justification a no-brainer.

What are environmental effects of choosing SIPs?

The SIP system has a very good environmental pedigree. Consider the following:

  • OSB used in Formance SIP panels comes from Sustainable Forests Initiative (SFI)managed forests. 
  • OSB  utilises 90% of the useable timber from the source tree. Compare this to 35% utilisation in timber framing.
  • EPS used in Formance panels is completely harmless and fully recyclable. 
  • The EPS manufacturing process (steam-expanded polystyrene beads) has a 25% smaller CO2 footprint per R value compared to fibreglass insulation.
  • Formance SIP buildings have a greatly reduced carbon footprint when compared with traditional timber framed buildings over a building lifetime.  

Choosing Formance is an environmentally responsible decision.

Learn more about SIP's here

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