One of the next steps is to get some engineering work done. We have selected Richardson Stevens Consulting Engineers in Whangarei to perform geotechnical research, take subsoil samples and create a site suitability report. They also look at stormwater management, do the structural calculations for the foundation, retaining walls and for the home once we have selected a building method.
Choosing a building method for the structure of the house has proven to be more difficult than I thought.
I am looking at cross laminated timber, different types of structural insulated panels (SIPs) and Metrapanel. Getting all the information on the material costs, R-values, speed of building, sustainability caracteristics and so on has taken longer than expected. Especially trying the get the material cost and cost of labour to put the structural frame together has already taken over two months (including the holiday period). Also the systems are very different and have their own advantages and disadvantages and it turns out it is like comparing apples with pears. Most likely in the end the choice will be based on other criteria than I had initially planned to judge the systems on.
Last week I had a meeting with the builder of the Metrapanel system who are the only qualified builders in the region to build with this system. Their waiting time is 1 year. They could start on our home late January 2018. It is however expected to be the cheapest system while we can still achieve high insulation levels so there might be some tough decisions to be made once we have all the data.
It’s all part of the game.
Cross laminated timber
OSB and PUR structural insulated panel
Magnesium oxide insulated panel