Wellington Builders | Design & Architecture Services | Eco-Friendly Design | High Performing Home | Structural Insulated Panels | Energy-Efficient Home
If you’re considering building a SIP (Structural Insulated Panel) home and would like more information on the process, then you’ve come to the right place! SIP builds are somewhat different to your standard timber build home, so Wellington builders Green Abode have set out the following steps to give you a good indication of what’s involved before you embark on your journey.
In this post, we’ll be covering the process from design to floor coverings. The steps are listed in order of how they would happen … in a perfect world. However, we all know that we don’t live in a perfect world, so please bear in mind that these steps may not occur in the order we’ve listed them.
Why are SIPs Important?
SIP homes have become increasingly in demand in New Zealand over recent years for their energy efficiency and fast construction time. Yes, they cost more to build than a traditional timber-framed home but are more cost-effective in the long run because of reduced power bills. They also create less material waste due to all the panels being cut to size in the factory.
Steps for Building a SIP Home
It is important to find an architect who has experience designing with SIPs. There are aspects that need to be considered such as the best positioning of the house on the site (ie north-facing), and the best layout for the ventilation system, lighting and plumbing - among other things.
2. Consent Application
In New Zealand, SIPs fall under the “alternative solution” category for local council building consents. Standard processing time is 20 working days, but Green Abode recommends allowing an additional 20 days to your project timeline, in the event of RFI’s (Request For Information).
3. Site Preparation
The site is cleared in preparation for the next steps. Also at this stage, the installation of temporary power, delivery of a portaloo, health & safety hazard boards and temporary fencing take place. Sometimes surveyors are also involved so that heights and cuts can be made correctly.
4. Plumbing Drainage/Pipework
The plumber installs the drainage/pipes required before the foundations go down. With SIPs, plumbing cannot be installed in exterior walls because of the possibility of leaks. Instead, they are located through interior walls and/or floors.
The concrete slab can now be laid. Green Abode recommends using fully insulated MaxRaft slabs which provide superior insulation performance, particularly at the edges of the slab where most heat bleeds from.
6. Installation of SIPs
This is an exciting part of the build when you get to see all the wall panels installed and the shape of your home begins to take place. This process is much faster than the installation of traditional timber-framed walls.
7. Exterior Wrap
Once all the walls are up, the entire envelope of the house is wrapped using a watertight membrane to protect the panels from the elements. Green Abode recommends a wrap supplied by Frame Protection Services for this job.
The SIP roof panels are usually lifted by a crane. Once the panels are down, the builders will lay more watertight paper (ie FPS paper) and then purlins are installed. After this, the roofers can lay your preferred roofing option (ie tiles, long run, etc).
9. Internal Framing & Window/Exterior Door Installation
All the inside walls can now be installed, along with all windows and exterior doors. Please note that although SIPs can certainly be used as interior walls, we don’t recommend using them in this situation due to cost and the fact that direct-impact sounds travel very well through SIPs.
SIP homes are high-performing, so to ensure your house performs to its fullest potential, Green Abode recommends selecting uPVC or European-type timber window frames for your double (or triple-glazed) windows. A large percentage of heat loss is from windows, so the higher their insulation rating, the more warmth is retained inside the house.
10. Blower Door Test
Although not essential, Green Abode recommends conducting a blower door test at this stage of the build. This test is usually conducted by a suitably trained specialist to check the airtightness of the house. The reasons for airtightness are to reduce energy consumption, avoid moisture condensation issues, and prevent uncomfortable draughts from leaking in from outside.
The testing procedure consists of a pressure gauge to measure the pressure differences inside and outside the home and an airflow manometer and hoses for measuring airflow. When the test is done at this point in the project, any air leaks can be resolved before the house is completed.
11. Electrical - 1st Fix
It’s at this point that you can make minor changes to where you would like all lights, light switches and powerpoints to be installed. The electrician can then begin to lay all cables and install flush boxes. Sometimes he or she will lay a conduit to pass cables through (electrical services are located between the panel and the internal cladding).
Recessed lights are never to be embedded into SIPS; instead, they are installed into an internal ceiling cavity (an experienced SIPs architect and builder will already be aware of this).
12. Plumbing - 1st Fix
The plumber can now install all pipework into the walls.
13. Exterior Cladding
SIPs can use just about any type of cladding you prefer if it meets the requirements of the NZ Building Code.
14. Exterior Painting
Green Abode recommends using eco-friendly paints such as Resene’s range of Environmental Choice approved paints which have no added or low VOCs.
15. Interior Doors
All interior doors can now be fitted.
16. Interior Linings
Some people prefer to embrace the look of “raw” aesthetic OSB board, but if this is not quite your cup of tea, SIPs can use any lining that meets the requirements of the NZ Building Code.
Now that all linings are in, your plasterer can come in and start getting things ready for the interior paint job.
18. Skirtings, Architraves & Scotia
These can now be installed, ready for the painters to do their magic.
19. Kitchen Installation
Your chosen kitchen company can now install the kitchen.
20. Interior Painting
As with the exterior painting, Green Abode recommends using eco-friendly paints such as Resene’s range of Environmental Choice approved paints which have no added or low VOCs.
21. Electrical Fit-off
The electrician can now commission all powerpoints, switches, the ventilation unit, and the extractor.
22. Plumbing Fit-off
The plumber can now commission all shower installs, taps, basins/vanities, toilets etc.
23. Floor Coverings
Your chosen floor coverings can now be laid. Because you’re building a SIP home, chances are you care about the planet and are trying to build more sustainably. Green Abode recommends using a sustainable flooring option such as timber, bamboo, or 100% woollen carpet.
Whew. We got there! Yes, it’s a rather long list but hey, we’re building a house after all - not getting a haircut. Building a home with SIPs is different to building a traditional timber-framed home, but hopefully, this blog has helped disarm any fears you may have had about building your own.
If you have any questions about building a SIP home or would like to discuss your ideas with our in-house architect, contact us. Our team at Green Abode would love to get you on your way to building your very own SIP home!