LadyBuilder

Thanks for your reply. I looked into ICF in the basement but decided against it. My worry was that if any joints are not done well and I get a leak/crack, it would be very difficult/expensive to find. I plan on using bentonite geotextile as my first form of water defence in the basement as it allows me to blindside waterproof on the piles. I am also currently exploring shortcrete for the walls. the idea of simply attaching the mesh to the piles and spaying appeals a lot. Unfortunately it is not so popular so not many people can advise... I've just send off for a quote with MBC, I hadn't really heard of it before coming to this forum. Given that I will have timber sashes, my worry is that they will not be airtight at all and the MVHR will not do much but waste electricity. I have to say that the size of the house is the main problem in making all these decisions. At 6200 sq feet, I need 2 of everything and it becomes rather expensive

Hi, Brief intro from me. We have just gotten planning permission to build a house in Central London. It has been a year from plot purchase to planning permission, but overall I think it has gone well, despite the changing concept completely. Started off with building a modern house on one side of the plot, ended up with planning for a Victorian house on the other side of the plot. Anyway, we are keen to be sustainable and energy efficient as possible, but have no need for certificates or accreditations. I run a interior refurb company, so I am in the building trade, but don't have much experience with building whole houses (small extensions, one tiny basement, etc). However I have decided to do the entire build pretty much with my people in order to fit into the budget that we have. I'm lucky that being Bulgarian, I have access to cheap labour, but unfortunately most of it is rather unskilled. We have an architect and structural engineer, but the rest I am doing pretty much myself. Which is a very daunting task and I will need all the help I can get.... hence this forum. We tried to keep the house as simple as possible. Large rectangular basement, two square floors on top and a liveable roof space. The basement is contiguous piles and a concrete box with a concrete ground slab. The house after that is either SIPs or ICF with a SIPs roof. I am really struggling with that decision. If SIPs, I have a great price, they come and do everything for me in 4-6 weeks. If ICF, I’ve got to get the know how and do it all myself with a bunch of guys who will expect directions and wisdom from me. However, I can’t help but think that ICF is more ‘robust’/long life solution to SIPs… Any advice appreciated! I am also struggling with all the decisions like MVHR or not (timber sash windows in a conservation area), air source pump or really good gas boiler etc. Finding suppliers for the thousand things I need is also a full time occupation. Anyhow, we start piling in January (I still haven’t got the Party Wall award or the water installed) and I need to sort out the drainage before anything else. Thoughts on connecting basement floor directly to sewer (what if it overfloods) or preferable to use sumps (maintenance, electricity and costs of materials!)?