FLF

I am looking to try and build my first home in the next year or so. My partner and I would have saved roughly £100-£120k by then and will hope to buy some land with that money outright subject to PP. My plan is to build a 2/3 bed bungalow covering about 100-120m2 in an L shape. After doing research for the last year a lot of my questions led me to this forum so I recently joined and would like to see some thoughts on these ideas. We are both keen on an energetic efficient ish home but if the costs become too high we will not be too fussed if we need to change the methodology of building the house (sip , ICF or other). As we are first time buyers and builders we are trying to make this as easy as possible and let professionals handle the building and structure of the house until a water tight stage and then we maybe able to get involved a bit more for the internal finishings. What I've come across so far is a sip company called JML up in Scotland. I briefly spoke to them for some quotes. Also attached an image for standard design prices. So the quote was to get to a watertight stage with them managing the project and ground works it was quoted about 130-150k, depending on ground conditions. Excluding the connections to mains for water and electric. So we were looking to finish up the project maybe borrowing -225-250k for the build and internal finishings itself. We were wondering if any other methodology would be cheaper? I've seen ICF with sip roofs and traditional block work. But from my understanding of is quite expensive? Look forward to hearing some opinions.