Conor

Sorry, forgot to say the bath is under a sloping ceiling, part of the reason of having it sunken, we can move it a bit further under the eaves, freeing up a bit more space for he shower area.

Anybody any experience with installing a sunken or semi sunken bath? Considering a partially sunken one in our ensuite, not by much, maybe 300mm. Are there any obvious considerations or issues with this? Building control regs? Will be on first floor... Concrete floors but would build up that part in timber. Boot room below and we've 2700mm ceilings so not concerned about losing head height.

@nod Northern Ireland... Materials and labour a dose bit cheaper here. But that's a rough price and probably misses a lot... But I'm aiming for sub £1k/m passive House build.

For ICF construction, I've been quoted £400m2 for a "thermal envelope". That's passive slab, intermediate floors and supporting walls, ICF structure and EPS roof panel system. Adding in windows, render and roofing, I expect this to come up to about £600m/2.

I had considered that... the flat roof area is about 2mx6m. And I've considered "cantering" the panels over the edge to act as a brise soleil... though I think it'll be far from pretty, and will be visible from the road so I don't think planning will like it! Unfortunately they'd be shaded as there's a three story Victorian townhouse to the West. And we have to plant trees on that side as well that will eventually add more shading. Thinking about it, the ground directly behind the garage will slope down a metre or so to the finished patio level.. I could possibly fit a set of ground mounted panels here. That would be another 5 which would bring me to 15 south facing panels, 4.5KWp, which would do the job.

Cheers everybody. I'll wait until the house is down and the timber is sorted.

I'm struggling to find a way to get a ~4KWp system on our south facing roof - we have a partial dormer cutting in to the roof and a projection for our master bedroom. I can fiddle around and squeeze in a couple extra panels to either side of the dormer or on either the east or west facing roofs on the bedroom projection. But even then it's barely 4KWp and its far from optimal with partial shading on some of the panels. From my understanding it can be problematic if you have an array with some panels in shade at different times of the day? Plus I want to use an in-roof system and doing anything other than a simple rectangle seems more difficult and expensive. Planning have also expressed concerns about visibility of panels on the Eastern roof and may stipulate that we dont have any panels here (still waiting on decision - we're in a conservation area) So, considering that, I think it's best to just have 8 panels on the main roof - should be unshaded all day except early morning. And then I can have at least 10 panels on the garage roof. Would need to rotate the roof ridge on the design but I can't see that being an issue with planning. Can I still use the one inverter setup or does this type of array require more gizmos?

Exactly what I intend to do. Seems simple and effective. Did you have your DPM under the insulation or above? And did you use EPS100 for everything or denser for the ring beam and load bearing walls?

Got one. Love it. I'll have a look at them properly after tlwe rip the house apart and see how they look... At least I'll have the option. But I do know much easier it would be to used planes graded timber... Worst case I'll have materials for out shed and garden office.

Thanks @Declan52. I'm considering taking a few off months to manage the job after the main contractor has done the ICF. I'm a project manager on large infrastructure projects... This should be a doddle lol!!

Is there any building reg requirement for using new, graded timber for stud walls? We'll be demolishing an existing house with suspended timber floors and hope to reuse some of the material. Could I use the floor joists (well vented and dry, no rot) to construct new partition walls in the new house? Joists are quite small, maybe 6". I understand that walls would be a bit thicker, but it's a large house so don't mind losing 50mm here or there. Will be using concrete supporting walls, so any timber walls will be for partitioning only and not load bearing - eg. Between bedroom and dressing room.

Really hope you are in the south of England because I'm hoping to come in around £750-£1000/m² in Northern Ireland!! Will be taking similar approach as well, plus we have a lot of materials from the demolition that we can use - roof slates, bricks and timbers.

We're in the same position (check out my post in Introduce Yourself). Though a lot about it and have opted to use the basement level for a guest suite, plant room and storage. The principle level will be the living area. We're going to partially raise the rear ground level with the excavated spoil so there is flow from kitchen to garden. That's an essential for me. Also really important to have kitchen accessible from your main entrance without steps... Think of carrying shopping in! Briefly lived in a three story town house that had kitchen on first floor... Hated it! Bedrooms are on the top floor, mostly as they will look out on to the trees and gardens behind us and floor area is big enough for three bedrooms and bathroom. I have a feeling we may end up in the basement bedroom in the summer tho if it's another hot one! Undecided on heating. After posting here and reading a bit more, think underfloor in the basement and then in bathrooms will be best. Convection will do the rest. Structure wise, it will be an ICF build, passive slab foundation, shuttered internal load bearing walls and a poured floor deck systems to create a fully tied in monolithic structure. Fingers crossed for an earthquake to test it lol!

As a general rule, pressure tests on pipelines are generally X1.5 the anticipated max operating pressure, or the max pressure rating of the system, whichever is lower. I'd expect the pressure on a domestic system to be no more than 1.5bar at the highest point and 2bar at the lowest. So test pressure of 4-5bar is adequate.

Toyota are dragging their heels. The "self charging hybrid" BS add campaign sums up their attitude.

Thanks Jack, you make a lot of sense. I will have an outdoor pizza oven so that'll take care of the wood.... How effective is an MVHR and distributing warm air through a house? I understand how they work, but if you are extracting 25c air from a warm room, how much of that heat will go in to another living space? I'm wary of these high efficiency claims!

Thanks Dave. Yeah, I think the losses due to our irregular water use from a thermal store would wipe out any savings we'd make from PV heating. And I'm already worried about over heating. I've been reading a lot on here about sunamp... doesn't seem like the product is there yet - the controls at least. I'm 6 months away from installing a system so lets see what happens in that time. Re flows and pressures.... my day job is an engineer in the water sector, so I've at least got this part covered! The reason why our current combi drops flow when other water is used in the house is old pipe configuration and the boiler has limited capacity. I'll be running a 32mm supply to the house, and the area has decent enough mains pressure.

I agree fully... but my other half is determined to have a fire of some sort. And I've spent the last month chopping 5 large trees in to logs!!! it's on the list and in the budget. It has a single bris soliel, but no active cooling included. We've since had thoughts about the location of the kitchen, which will result in some of the south facing glazing going, and we'll be doing a part buried basement so the big slider at that level will be going. I also think I might be able to use some sort of ventilation to use the large concrete volume in the basement as a heat dump. I will work with our architect more on this, I want it remodelled at 22c in winter. I had thought about those simple single unit heat pumps that work as aircon in summer and heating in winter... you know, the big fan units they use in houses in southern Europe.

Hi. Firstly, not sure this is the correct place to post... never seen so many sub-forums in my life.... We're building a 245m2 passive(ish) house this year. South facing, plenty of solar gain when need (bris soleil and external blinds to minimise when not wanted). https://forum.buildhub.org.uk/topic/9228-hi-icf-project-in-holywood/ We're in a town and on mains gas, so it seems by far the most logical source of energy for heating and hot water. As much as I want to de-carbonise, a heat pump doesn't make sense in our case. So, that part is sorted. As we'll have triple glazing, ICF walls, large thermal mass, high air tightness, our energy demand will be low. I don't see the point in spending thousands installing a central heating system. Plus we'll have a wood burner - will be rarely used, so not fussed if there's a back boiler on it. Our initial PHPP assessment attached. I'm thinking plumbed towel rads in wet rooms and maybe 2kw post heaters (3x 150mm - one for each level - each with own control e.g. central warm water heater) Any issues with the above? Would also consider electric under tile heating mats for the master en-suite for my other half's chronically cold feet... My main query is hot water.... there's just the two of us and we both travel a lot for work so we've no regular routine. We have a combi boiler in our house which is great.... but hate the long delay for hot water to come out of the tap and the massive pressure and flow drops when somebody else flushes a toilet or turns on a tap. So I'm ruling that out. I'm also planning on a 3-4KW PV system with solar diverter to provide hot water in the summer... so that means some sort of storage. What are my options? In summary, we need instant DHW on demand, high flow rates, low running cost, heatable by gas and PV. Thernal store, unvented HW cylinder or sunamp type storage? Really unsure!!! Thanks

I've looked at costs (very roughly!) On this and gas always comes up on top. The payback on ASHP is quite long over gas... And that assumes nothing goes wrong with the unit and service costs are comparable to gas. I just feel that ASHP tech just isn't there yet. I can get a gas fired system installed for half the price of an ASHP system and running costs are about the same (5p/ kWh assuming COP of 300%). My last boiler service cost £45. Am I missing something obvious? I'm all for decarbonising but doesn't seem to make sense if you are on natural gas network.

We bought all of our bathroom tiles from them plus my brewshed. No issues, quality is good for the price. It does help that I'm 5min drive from my nearest store

Think we will be enclosing the rear of the basement at least partially. Going off the idea of having living and kitchen elevated above garden. Think it will also come in cheaper as we'd be losing a sliding door and a bit less material to depose of... But would lose the under balcony storage areas. Decisions! Agree with the colours... Will be a lighter grey than shown. Render will be an off-white.

Cheers! That's what I had initially thought. But struggled to find anything firm online from manufacturers recommending/ approving this. I have priced this method and for our build EPS comes in about £3k where as "passive" ICF is an additional £9k over standard. Clear winner.

Thanks Will, very happy things are working out now! Yes, I'd considered buying standard ICF blocks and adding on an additional 100mm EPS. Not sure how I'd go about it tho, what adhesive would you use? Those blocks look quite a handful to work with.

Hi Declan. Yes, visited a couple houses - an off-grid one just up the road and I've visited one in Carryduff that's similar size and mid construction. Both by Johnny Balantine using integra spec. Also been to John McClatchys house which is a Logix build. Main reasons for using ICF are speed of construction, simplicity, inherent air tightness, ease of waterproofing for basement. I hope to do as much as possible myself.. no way would I take on a traditional house build.