dnoble

Having some conflicting advice on what to use round windows from window supplier and carpenter. Rationel triple glazed alu-clad timber frames going into an MBC timber frame SIPS house. Should I get expanding tape to fill the gap (22mm tot, or 11mm each side hopefully if everyone's measured correctly), or just use sealant and expanding foam in from the back (cheaper and possibly simpler to do, especially on the big windows). Also do I need a DPM under the base of the window as well as the folded in breather membrane? Any advice appreciated Dan

Thanks for the replies I'm cladding it with larch from a local sawmill just over the bridge in south wales. I was surprised to discover that hit + miss boarding was about half the cost of milled shiplap, and quite a lot less than plain square or Waney Edge boards. thanks for the info about grain orientation. Hadn't realised it also applied to the lower layer, but this makes sense The boards are 150mm for the lower and 100mm for the upper layer with a 25mm overlap on each side (150mm boards being 50m apart) It'll be interesting to see if I can ascertain the curve of the grain in pieces this small. Sounds as if counter battening with roofing battens is the way forward, and you're right they are pretty cheap. what's the difference between the blue and red ones. I'm assuming it's for boy and girl roofers?

Hi Miek Thanks for this advice. What's the trick to making sure they "cup" inwards. Presumably it's to do with the orientation of the grain? The advice from the cladding site is that counter battens not needed with board on board (though it does suggest using angled battens). Is the feeling here that I'll need to counter batten if using normal square battens? It's going to be a fairly sheltered site with trees and overhangs providing extra rain screening etc. (I want to keep things simple/cheap if possible)

Thanks Those are both good points. Sarking board cut down middle is a good idea (though extra work as I'll need loads, plus they'll need treating on cut edge)

I'm thinking of doing this. Usually with vertical cladding one needs vertical counter battens. This site suggests you don't for board-onboard because there's a void at the front. BUT the battens need to be angled forwards. My question is, where can I get cheap treated battens which have a 15deg angle machined in or would I have to get them specially made (which will probably negate the benefit of not needing vertical counter battens) https://www.tdca.org.uk/timber-cladding/cladding-design-detail/vertical-cladding-new-buildings/

In theory I think it's advance though not sure I understand the difference... This mortgage seems to depend on what you have built being valued at a level where they will lend you 75% of it's current unfinished value. I think they will release some money when the foundation is done. It's just ideally I need this as the foundation is done. Presumably they'll release more when the Frame is delivered and up, though the agreement with the frame company is that I will pay them a Lump on delivery. I'm going to have to wait for another valuation and report from surveyor. I hadn't really clocked this where I signed everything which I shall have to chalk up to experience I suppose..

I have a self build mortgage with Ecology. What I hadn't realised is that release of each phased lump of money is dependent on a surveyor coming and looking at the site and confirming that after whatever has been done, the current increased value of the build means they can release more money. This seems a bit peverse, as often you need to have spent the money to achieve the work which will increase the value and release the money! Specifically with a passive timber frame house, much work is off site there is nothing to see until they deliver and erect it.. But the frame builders (MBC) want a proportion of the money before, and on delivery. Similarly Ineed to pay half the windows + doors cost; a big lump, but said windows are not on site to be seen yet.. Has anyone else encountered this rather bizarre catch22 situation? Any advice for negotiating it. Ecology seem to just read the rules they have written down Dan

Thanks Nick. bearing in mind it's a passive house and the pipe will form a thermal bridge I thought there might be some need to do this (I'll check with the frame builder)

Thanks for the replies. Mike Sharp; there's nowhere in the slab nearer which would avoid the problem unfortunately. by protect and insulate it, I suppose boxing it in and wrapping in something insulating would achieve this?

We're just finalising the insulated foundation for our MBC timber frame house. because of an oversight about levels etc it looks like the ground floor level may be too low to get enough drop to connect to the main drain in the road. are there any reasons (other than aesthetic) eg from thermal envelope or building regs POV why we can take the pipe straight out through the wall at "toilet level" to gain an extra 300mm? Any other smart solutions would be welcome (though I'm not keen on using pumps or putting in a treatment plant) many thanks Dan

Thanks Curlewhouse, that sounds like good advice. Presumably if I went with the Council/LA one I wouldn't get to choose who was allocated?

I had a surveyor come round yesterday to look at the plot for the self build mortgage folk. He asked who the building inspector would be and mentioned I could use the council one or employ a private company (which he implied might be more flexible/pragmatic etc) I hadn't realised this was a possibility. Are there benefits of one over the other. Is there usually a significant cost difference here?

Thats a clever workaround. I've spoken to the environment and they agree in principal it should be fine but agree that the stream doesn't officially exist. They also didn't know how or what the process is for getting it verified.

Hi Jeremy. I agree I'll need to incorporate some kind of attenuation. Specifically though I need to know if allowed to use this stream which doesnt oficially seem to exist for the overflow (I'd like to as would avoid me having to sent ot otherwise to main sewer)

Currently formulating a plan to deal with rainwater from 160m2 roof. Heavy clay means soakaway probably not an option and PO seems to acknowledge this so maybe able to negotiate connection to main drain.(Also having some attenuatiuon in the form of green roof and rainwater harvesting) There is a intermittant steam in the garden that only runs after rain and disappears into the ground 10m or so away (still in the middle of my land) This stream isn't documented on any plans or surveys. I wonder if I could send my roof water into this (it probably goes there any way as land house will sit on drains into it.) My concern is whether anyone will reconise this stream as an entity. Is there a way of documenting it? Dan

OK maybe I could do it myself then? There doesnt seem to be any objective siting in the plans other than the distances from neighbours properties, so I suppose as long as I respect these, keep it the right size and the angles all square, maybe it's more straightforward than I thought?

Well done! Did you use a digger? Burt it's actually the accurate marking out of where the house goes I need to sort out

Probably an obvious answer to this but I'm planning an MBC timber frame and getting quotes for doing the groundwork which involves digging a massive rectangular hole and half filling with compacted hardcore. I have a basic site plan which was used for planning app etc showing the position of the building. Who can actually accurately mark out the site in real life? I would do it myself but am anxious it'll end up being wrong and have to move 1 foot to the left. I am getting a structural engineer to plan a retaining wall at one end but presumably I need some kind of surveyor? Dan

Thanks for all the replies. It does seem that a woodburner would be an unwise extravagance. I'll have stick to bonfires I hadn't considered adding an ASHP also. Would this be to pre-heat the water so the stack needed to do less work, or will it actually directly charge the stack (presumably using less electricity). Any recommendations for ASHP type and price?

Good morning I'm building a passive standard MBC house and planning the hot water. I had planned to have a large thermal store heated with solar thermal in summer and backboiler off a wood-burner in winter. Going to have 4kw PV system on a SW facing roof which presumably wont provide much help in winter. Having read of Jeremy's travails with heat loss and overheating I think a sunamp stack would be a better way to go (have 4 children who occasionally take showers and may at some point wash regularly) Speaking to the sunamp guy, Andy, it seems relatively straightforward to charge it from a backboiler on a woodburner. However I'm beginning to get the impression that a woodburner probably isn't the best fit for a passive house (overheating, cold bridges with chimney and direct air inlet) and the Neanderthal in me is (very) reluctantly thinking if letting this idea go. So... 1) Does anyone think a woodburning in a passive house is a viable way to charge DHW in winter (I have access to a lot of wood btw) I think there may be some models which direct most of heat to back boiler and I could also send some to UFHS via the sunamp 2) If not am I stuck with charging the sunamp in winter using mains electric/E7 etc (I don't really want to get a GSHP or connect to mains gas) Best wishes Dan

Well I've dug a hole and done the percolation test. Neighbours were pretty jealous of my new hobby of watching a hole of water very slowly empty There was solid clay about 25cm down so it was pretty slow. 500sec which comes out at 3.3sec/mm drop I assume this indicates fairly poor drainage and will mean more serious measures needed. I'm struggling to work out from the guidance/info how to translate this number into a course of action for draining the driveway. It is about 50m2, previous lawn. I was planning to dig out the topsoil, put a membrane downs, hardcore/crushed stone and then gravel/shingle on top. The main issues I think will be avoiding any drainage onto the pavement and onto my neighbours driveway which is slightly down hill (there's as step down of about 30cm onto the level of his front driveway; also gravel. Presumably some kind of French drain or filled gully along those 2 borders. How would I know if I need a larger sump (attenuation cell?) like you used, Jeremy. Is there some kind of formula which indicates it or should I just assume the worst, belt and braces it?

Actually, though it doesn't specify that, I suspect this will also be required for the new build so I probably do need to cover both aspects, thanks both for pointing that out... I was planning to save rainwater for toilet flushing and then garden watering but hadn't drilled down into details about how this would happen yet.

Thanks very much for that really helpful reply Jeremy. Pavingexpert is a useful resource too, Vijay The percolation test looks straightforward. Not sure I fancy digging a 1m2 x 2m deep hole for the ground conditions test, though! The frustrating part if this is that if I'd just decided to make this same driveway for the existing house outside of a planning app I wouldn't have needed consent or any conditions. They really seem to've chucked he book at us as it's part of a new build

Hello Jeremy. You very kindly showed my wife (Timna) and I your great house a year or so ago if you remember? Its taken 2 years to sort get this planning! The drive is going over some existing lawn and I'd have thought would be as permeable as that was. Obviously more complicated than I anticipated. Does this mean I'll need a certified drainage person to do a report (along with the arboriculturalist, the ecologist, the contatminated land-ist etc etc), I'm not sure the LPA will accept my hole+ bucket of water test (though if I can do this myself I'd be more than happy to?) It's becoming apparent that there are many hoops to jump through each needing a report form a consultant or specialist..

I've just secured planning (hooray) after sensible counsillors unanimously voted to allow against planning officer advice. The decision has arrives with a massive list of jargon-heavy conditions which I am slowly translating into plain English I am making a new driveway; Plan is to remove topsoil, porous membrane, crushed stone + gravel (so free draining). This paragraph below outlines the requirement. I'm sure my plan fulfils it, but can anyone point me rto a proforma or way of formatting my plan so it conforms to this? Any help gratefully received Dan Sustainable Drainage System (SuDS) The development hereby approved shall not commence until a Sustainable Drainage Strategy and associated detailed design, management and maintenance plan of surface water drainage for the site using SuDS methods has been submitted to and approved in writing by the Local Planning Authority. The approved drainage system shall be implemented in accordance with the approved Sustainable Drainage Strategy prior to the use of the building commencing and maintained thereafter for the lifetime of the development. Reason: To prevent the increased risk of flooding by ensuring the provision of a satisfactory means of surface water disposal is incorporated into the design and the build and that the principles of sustainable drainage are incorporated into this proposal and maintained for the lifetime of the proposal.