F.A.Q.

You have questions, we have answers
What are SIPS?
Structural Insulated Panel System – panels, made of rigid insulation between structural facings. Our panels are factory-made in New Zealand and provide a high level of structural strength, rigidity and insulation. They can be used for floors, walls and roofs, replacing the timber framing, batts and rigid air barriers. Panels are load-bearing, capable of spanning distances on their own, and providing bracing all in one.
What are the advantages of building with SIPS?
  • A stronger building. Stronger in a cyclone, stronger in an earthquake, and better impact resistance. You won't need to find a stud in a wall – you can attach anywhere.
  • Better insulation. Anywhere from 2x to 6x as much. Read the section about 'R-Value myths'
  • Less air leakage. About 20x less.
  • More fresh air. We'll make sure you get a suitable MHRV so that you get fresh supplied air, dispose of stale or damp air, and don't lose the heat you have.
  • With MHVR, there will be no condensation. Full stop.
What are the potential downsides?
We're honest, no system is the perfect answer! SIPS is a bit more expensive than a timber frame building built to the minimum requirements. That's because the minimum requirements under the NZ Building Code are so low. The cheapest panels we sell will give you a stronger, more airtight, and better insulated building. Once you increase the 'stick frame' system to the same performance, SIPS will actually be cheaper.

Builders are trained as carpenters, and most have little or no experience of SIPS. You may need to phone around to find the right builder. We're happy to help them get up to speed if they're keen.
    Why get panels from SIPS Direct?
    Because we make a premium quality product which is sold with less markup.

    Our quotes break down the panel cost as well as the accessories needed to finish the structure.

    We work with community groups to get them bulk product at discounted rates.
      What are the 'accessories'?
      Apart from basic panels, you'll need timber (for plates and trimmers), splines, screws, adhesive/sealant, expanding foam, flashing tape, an MHRV and maybe some tools. While you could hunt around and find them yourself, if we supply them, we can assure you of the quality, the timing, the quantities, and the cost. You won't be able to find the items cheaper and easier yourself.
      What is this MHRV?
      Standard houses will 'sweat' on the inside, especially if you sleep with the windows closed. Most of us release about 2 litres each per night, and it has to go somewhere. Some goes out under the door, some through little gaps around the windows, some through the plasterboard, and some just condenses on the walls/curtains.
      Most people know HRV/DVS. They are basic fans that pulls air from your attic, down into your house. This brings the most heat on a summers day, and no heat when there's no sun. Aside from poor thermal performance, your SIPS build probably won't have an attic, and your building will be too airtight for a positive-pressure system.
      A MHVR has two fans, one to suck waste air from your house, and another to blow fresh air in. The two airflows pass through filters, and a high-efficiency heat exchanger. The ones we recommend achieve ~94% heat recovery. If it's warm inside in winter and cold outside, you get fresh air, but at indoor temperatures. Most units have variable speed fans (from zero up to a light breeze) and can be controlled by moisture level, timers, CO2 sensors or manually.
      Can I skip the MHVR and just open the windows?
      No. What's the point of having a highly insulated building and then opening the windows and letting in all the cold/hot? What's that going to do for your energy efficiency?
      Also, that strategy is barely successful with leaky timber framing. SIPS is 20 times as airtight. Built it tight. Ventilate it right!
      What special tools should I have?
      If we pre-fab the panels for you, you'll need a sealant gun. There is a lot of sealant – you'll save time and energy by using an electric/air driven gun. A nail-gun for driving the perimeter nails (coil nailers are better). You'll also need a high-torque impact driver (even the lower-tier models of the expensive brands will struggle).

      If you're doing on-site fabrication, you'll also need a hot-wire gun, table saw, drop-saw and a beam saw. Fabricating the panels is labour-intensive, so unless you have a supply of cheap labour, it is usually significantly cheaper to have as much work done in the factory as possible.
      If you didn't find the answer, ask us and we'll reply you.