mike2016

It's liability insurance i need. You can't get latent defects insurance for one off builds any more in ROI which is sad.

So the site is almost ready to start, my house is sold, moving out this weekend. Got the last tree stump ground out so there's nothing blocking the foundations. But the reason we write some of these blogs is to vent frustrations and in my case today it's about insurance. My site has Made Ground. I went through the trouble of getting a ground analysis with dynamic probing and there is good load bearing at 2.2 meters but it's poor above that. I switched Structural Engineers and Tanners in Cork did a great job looking into piling and groundscrews before settling on groundscrews. Anyway, I have a design, someone lined up to build etc but before I sold I wanted to get my self build insurance in line. I had focused on scaffolding issues as I may need to put scaffolding on a public footpath at one point or in the neighbours side passage so I was making sure this could be accommodated. In my ignorance, a lot of which I'm going to experience during this project, I didn't think for a second that piling / groundscrews would be an issue for an insurance company. So today I got the big NO from the insurer so I'm ringing around trying to check if there are ANY underwriters willing to take this on. Time to start posting questions in forums etc! I'm based in the Republic of Ireland just so you are aware. Anything non standard is very hard to get covered at the best of times! Will I be able to build, I'll find out in the next few days! Contracts are signed, I'm moving out, new house prices are crazy, maybe time to move to Thailand or the Philippines? What can I say?!

No movement due to the air but you may have other cables or pipes in close proximity and in my attic I often kick the ducts as they are under the insulation as I am moving about. I just like knowing they stay where I left them!

Did you get an air tightness test performed, if so what score? What type of ventilation system is there? Do you have trickle window vents, a stove / flue or leave interior doors open or closed a lot? Sounds like air movement of colder air, maybe stratification disturbing the layer of air around your body. Try a thermal camera and test temps at different heights in the room.

The car batteries aren't meant to be fully charged and discharged regularly (daily) although slow charging will help longevity. Home Batteries use LFP which is designed for this usage / profile. Only recently we've seen these enter the EV market. The key hinge point is that your car has to be in situ for the house to use it. You can buy ex leaf batteries separately to get the cheaper capacity or purchase an Ecoflow battery that accepts dual fuel, Solar PV or Propane which will help in Winter. Your space heating loads will be much lower in a passive house than your hot water requirement, that's going to be the biggest energy load. Then you can look at off peak charging / loading of the battery / sunamp or Tepeo ZEB boiler to time shift your usage to the cheapest period.

Am looking into buying second hand toilets for my new build. Would it be easier to get rear discharging ones as they have a bit of play with placement, especially on the ground floor as waste pipes in concrete may not exactly line up? Same for upstairs? Any other advice? Thanks

Congrats - went to see their show house, looked very nice and almost a one stop shop. Love to the see construction photos if you're around onsite next year!

Still in the Sales cycle for my old house (3rd try!) but while I'm waiting I'll be doing site clearing work next month and I want to take a moment here to make final decisions on my wall build up as this moves the locations of my floor penetrations by 100mm. Target U Values are as follows: 1. External walls U value = 0.1 W/m2K 2. Sloped Roof U value = 0.1 W/m2k 3. Floor U value = 0.07 W/m2k This is based on PHPP calculations, they are more strict as my house is quite small, 110m2 and box shaped. This ratio of floor to wall is harder to tick the PHPP boxes so the U values are dropped. Anyway, I'm not going for certification but plan to AIM for these where possible. Back to my wall: The original Wall used 50mm Kooltherm and an insulated service cavity to meet the U values and save space. I'm not keen on the fact that the Kooltherm isn't breathable so was going to switch it to 100mm Gutex woodfibre board. Then came the question of how to attach the Intello air tightness membrane to Gutex! It would likely require additional framing onto which the Intello membrane is tacked on top of which the service stud work would be added. The Gutex supplier though suggested another product instead of Intello: https://www.ecologicalbuildingsystems.com/product/superpan-vapourstop It's a 25kg board. I would fix through this & the Gutex into the 220mm Timber Frame studs to hold everything together. Then use air tightness tape to seal it up. The last question is if I should insulate the service cavity or not? This creates problems for the electrician and requires derating the cable so you use 4mm instead of 2.5mm and 10mm instead of 6mm is my understanding. The cost is one element but trying to route the heavier cable and fix it into back socket connectors & cookers etc must be harder too. The option I'm strongly considering is putting in 150mm Gutex and using that Finsa board, sealing it and then building an uninsulated service cavity onto this. I can pre notch the service batons for future cable runs, I can run standard size cable and any later cables added will be easier to run without fighting the insulation. The downside: I lose an extra 100mm on all outside walls. I modelled the original Architects plan and my own using the 150mm Gutex and think my own is what I'll go with. The service cavity vs derating cable is the main driver and it's simpler to maintain once built. The final question is if this approach will work on the vaulted roofs or not. Those 25kg Finsa boards sound heavy. Hanging those, then service batons, then 15mm Fermacell boards and it all hangs off 225/250mm lag screws between the Finsa board, through the Gutex to the 220mm Timberframe sounds like a lot. An option is to fix 100mm Gutex using long screws and washers as per external insulation fixings, then add 50mm batons with 50mm insulation between them. Now I can staple Intello to it and build up the service cavity and add Fermacell. That's my thinking - I'll chat with the supplier about vaulted ceilings and see if they agree. Both wall types are modelled below.

My Architect specified Moy Metac or equivalent for the 50mm service cavity as part of the overall insulation package. I have 220mm Moy Metac within the timber frame itself and 50mm kooltherm inside of that. Was going to swap the kooltherm out with 100mm Gutex for breathability. Just need to decide if I should fill the service cavity or add another 50mm to the Gutex to be done with it!! I'll be flagging with the Electrician if I fill the service cavity or look at some trunking option to carry this cable inside the service void if this offsets the derating somewhat but I doubt that exists? Or surface mount everything and go full industrial!! The depth of the wall affects drain positions etc so I need to make this call up front! Good topic for me to follow!

Mark Brinkley - Housebuilders Bible - 15th Edition just out. https://www.waterstones.com/book/the-housebuilders-bible-2023/mark-brinkley//9781916016835 Google has it listed under Architecture & Religion for some reason?! Not the guide you want to covers nearly everything else, costs etc. Best guides for you would be on youtube - skillbuilder is doing an extension series currently. Up to Episode 5 so far. Lots of other great channels but you may have seen this already?

Just saw these on bpc's website. Intumescent and adjustable flow. They have different sizes and other fire products too: https://www.bpcventilation.com/metal-fire-protection-valve-supply

Unfortunately, hard to limit penetrations. One suggestion for PV is a single cable for up to two strings: https://youtu.be/OmHtcfWUI4w

If its a single window I would be less worried about the overheating element in option 2. It's not that big glazing wise compared to the conservatory experience and your peak sun time has shading anyway. Even an internal shade will help a bit. I like being able to open the window though for stack ventilation in the evening though.

I got this on some of my new paving slabs. Was told it was efflorescence due to moisture in storage. It all gone now. Will take some time though. Give it a year?

So the SE has got costs back for both Ground Screws & Piles - 18K vs 35K so we're going the ground screw route. The exact number TBC (currently estimated around 90). They had been looking at a type 2 compacted layer 300mm above the screws but are now looking at a 200mm structural raft foundation directly on top of the screws. Then the insulated foundation is placed on top of this. Bakck of packet costs now as follows: 30K groundworks and install of Kore insulated foundation 7K for Kore EPS 20K groundscrews circa 10k ? for 200mm raft So about 70K for the foundation. Against this the Irish Government has waived development contributions and water / sewerage connection charges until next April 2024 if you finish building before Dec 2025 which is 12k + 9K savings so the foundation should work out around 50-60K when all is repriced and if we start say in January 2024. With everyone on holidays it will be September before the SE gets back to me with a delivery date for the final design meaning selling my house will delay things into 2024 I'd say. Was holding off hols myself, so this may trigger a break for me before this all kicks off!!

For drinking purposes the only two methods I've used are Reverse Osmosis or Distillation. I've tried both with good results. Whole house softening is a whole other ball game!! Most posts I've seen here are using the softening system with salt, that seems to be the go to. The only alternatives (but I've not heard convincing results from) are: Electronic (magnetic pulse transformer) Magnetic Electrolytic These generally have a specific life span. They suspend rather than remove. A Lime and Soda process is usually reserved for industrial applications. I would love a whole house distillation system but unless I had my own Hydro / modular nuclear reactors in my shed would probably not be able to afford it! Interested to hear what others are doing too.

I was thinking about the split between work I'd like the Plumber to do vs what I can do myself. I need to get a certificate of compliance with building regs which is pinned to the Plumbers PI insurance. This is in the Republic of Ireland. I would like to do some of the work myself but there's likely to be a split between what I'm allowed to do and what the Plumber will insist on so they make some money on the work and don't risk their insurance with work I do. The following are some of the tasks I have in mind and what I would feel comfortable doing vs the Plumber. This is primarily to save cost but also I'd enjoy the challenge doing some of this. I would welcome comments about what I should stay away from / what the Plumber should do. I know this is sometimes down to the relationship with the plumber, but assume there isn't a close one (not a mate): Plumbing Design - drains etc - Plumber Drain installation in Foundation Slab - Groundworkers / Plumber Hot & Cold Pipe Plumbing - Plumber Rainwater Harvesting Piping - Plumber (this RWH is a requirement by the local council) Connection to Mains, Hot Tank (Heat pump monobloc installed by other) - Plumber Wetroom installation - Me (This could be expensive otherwise but is likely to be contentious if I do it) Tiling - Me Fixture installation - Plumber Commissioning & signoff - Plumber At a high level that's what I'm hoping for. Supply would be mostly the plumber to bump their margins but some second hand stuff will be provided by me to save costs. Are there any items that I should look at doing or do I leave everything to the plumber but have to sink the cost somehow. There are options (no wetrooms at all or only 1 out of 4 or do later myself? 3 bathrooms and laundry room I was planning on tanking) Thoughts? Thanks!

There's not going to be THAT much temp difference between the floors surely? I like a cooler bedroom. Do you have an office or someone who likes it warmer to cater for? All the rooms are within the fabric and with PassivHaus the temp swing would be minimal without solar gain skewing things. Leave upstairs doors open a bit to spread the heat. Fan coils should work fine to top up. Ufh upstairs I would drop. My plan is for NO ufh at all, air to air with two internal cassettes, one in living/dining/kitchen open plan downstairs and a second in upstairs office and that second one is optional according to my heating consultant. He said ufh is overkill for me. Separate monobloc a2w for hot water that vents directly to outside. I have a very small house though, 102m2. This approach halves my heating system install costs too.

For noise you would really need 3g or better. Velux do a passive roof window that has 5 glazing units in it too. I lived in a converted attic with old double glazed units and it was noisy some nights (years ago). You can use 3G carefully around the house i.e. north facing windows and where road noise would be an issue and 2G for the rest. I'd go 3G throughout just because why not, unless cost is a factor. I don't rate Velfac myself having seen them up close. Rationel I love, aluclad would be my preference. For roof windows you're really looking at Velux or Fakro but Velux would be more popular and I think slightly better range and quality still? Best of luck with the project!

Make sure you keep the ducts dust free / seal them until the build is finished. Have you a plan for the external penetrations & keeping insects & water out? Ideally they should be on the same side of the building and / or 2.5 meters apart. Consider handiest location for the controls and isolation switch in case your neighbour starts burning their tyre collection! Take your time running the ducting, strap well & insulate if running through a cold area (cold roof).

Thanks Folks, Lots to think about. I had an extensive ground investigation report commissioned with window sampling and dynamic probing. That's when I realized it was made ground. From the report: The sequence of strata encountered were consistent across the site and generally comprised; • Topsoil • Made Ground • Cohesive Deposits • Granular Deposits TOPSOIL: Topsoil was present to a maximum depth 0.20mBGL. MADE GROUND: Made Ground deposits were encountered and were present to depths of between 0.20m and 1.00mBGL. These deposits were described generally as brown slightly sandy slightly gravelly Clay and contained occasional fragments of redbrick. COHESIVE DEPOSITS: Cohesive deposits were encountered beneath the made ground and were described typically as brown mottled grey slightly sandy slightly gravelly CLAY with occasional subangular to subrounded cobbles. The strength of the cohesive deposits typically increased with depth and was firm to stiff or stiff below 2.20mBGL in the majority of the exploratory holes. GRANULAR DEPOSITS: Granular deposits were encountered below the cohesive deposits and were typically described as brown/grey sandy clayey fine to coarse subangular GRAVEL with occasional cobbles. Based on the SPT N values the deposits are typically medium dense and become dense with depth. The pull test was using 1.5m groundscrews - yep, just like a big wood screw, stainless steel. My original SE was asking for 2.2m deep strip foundations before I sought alternatives, groundscrews / mini-piles being a potential solution. That felt like too much risk, too close to boundaries and would need perfect weather. The groundworker was sure a raft would be fine without any fuss but he can't sign it off, that has to be the SE. Good idea to tease out options and thanks for the extensive explanation above. I'd have to read it a few times to fully get the gist but worth looking into. The flange appears to just screw onto the top of the groundscrew and isn't further welded. Lifespan of a house, not something I had though about before this exploration! Expiry dates like cartons of milk - I can see insurance firms getting in on the action and charging more for older houses someday! But 50 years will see me out!

The site is 11m wide, narrow once the structure is built (9m wide) but 22m deep (10m deep house). The 450mm foundation will probably be 300mm EPS with 150 Concrete with rebar as I'm going after a Kore Raft Passive Foundation, ideally 400mm EPS but that's to be discussed as I'm chasing lower U values if possible/affordable.

I rented an aluminium platform tower for a week and they've not been back to pick it up yet 3 weeks later!! It's off hire but I looked into buying one for indoor / outdoor work. Can be moved and dismantled by one person although easier with two. Would buying one be an investment and you could always sell later to recoup some money?

Looking at 80-90 ground screws for my design, a few more than I expected! They need a minimum distance from each other or they don't work as well. The minimum spacing is 10 x the screw shaft diameter (76mm in my case) so min 760mm spacing. Expecting spacing to be 0.75m and 1.75m centers. Build up (top to bottom): 450mm Insulated Raft Foundation, 300mm type 2, groundscrews. Will be interesting to see the final Design. Estimating it might be up to 15K for the groundscrew element alone though! Still to get official pricing though. Hopefully it's affordable....! Added: There will be 400mm x 400mm plates on the screw heads. I had thought the concrete raft would sit directly on these but there is 300mm type 2 between them. Maybe I'm reading things wrong - geogrid ground reinforcement was also mentioned in this layer. Lots to get my head around!

They did try to explain the load factor to me but it didn't quite penetrate my cerebrum! I may still need screw piles for some point loads. There is a lot of contingency built into the calculations for worse soil conditions than mine, higher loadings etc. It's a whole new area to me!