epsilonGreedy

Where does your 0.11 U for a floor come from, a Kingspan advert perhaps? Part-L building regs quote max allowable u-values (limiting fabric parameters) for building elements and another set of more demanding figures for ideal "notional" model u-values. A house may have a floor u-value of 0.30 if it otherwise meets a total energy performance target. The notional target u-value for a floor is 0.13. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/540326/BR_PDF_AD__L1A__2013_with_2016_amendments.pdf

I echo this and I am reminded of my previous house sale. Getting an acceptable offer is the easy bit, successful completion of the whole fragile conveyancing assault course is where a true local professional EA can shine through. My last house sale happened because the trad high street EA had a large database of buyers in his head and he knew my house was perfect to resuscitate a recently collapsed chain of local buyers and sellers. There were many bumps during conveyancing and the EA had an interest in 2 chain sales and so worked very hard to keep the chain alive with subtle social engineering. EAs are market makers and the UK housing market is becoming steadily more illiquid as the manifest gulf between perceived value in the heads of older owners confronts the real poor economic prospects of the young.

Point of order. The promotional material publish by the pro cavity bead industry actually states that the glued bead lattice is permeable to water. Unlike batts the bead lattice is self draining, this is a positive apparently.

A common complaint in this forum is about mainstream building subcontractors making mistakes and taking shortcuts. I am flummoxed as why I should be castigated for seeking clarification on the finer point re. where cavity fill insulation should stop. This is obviously a general industry concern and is a subject of evolving official standards. 10 - 20 years ago it was accepted that cavity batts should stop at DPC, now today in pursuit of better insulation the experts have decided to trade positioning insulation lower in the cavity for lower heat loss.

Most diagrams of foundation/footing designs show a continuous dpc/tray at dpc between the inner and outer masonry walls. Why is such a tray preferable to two independent dpc's particularly in view of the obvious risk that the tray promotes the formation of mortar damp bridges? All I can think of is that it creates a barrier to noxious gasses rising out of the ground and into the upper cavity. Before posting I did my own reading and found this NHBC advisory about the subject but in fact it covers complex cases and not ground level dpc. http://www.nhbc.co.uk/NHBCpublications/LiteratureLibrary/Technical/TechnicalExtra/filedownload,58010,en.pdf

Yes ridge height is limited. So far in my design we have got away with regular roof trusses coupled with 2.4m and 2.38 ceiling heights. My neighbour has gone for raised joists in his roof trusses. My budget for floor insulation was based on some threads here about where to source this stuff at a keen price, so probably not hi-performance stuff. Re. flow screed... everyone in the local area assumes this is what I will be doing even though on all other matters conservative traditional building techniques rule.

Well that is very odd since it is a universally recognized factor in any debate over full fill cavity insulation, why do building regulations recognize rainfall zones when full fill cavity insulation is being discussed. Anyhow mortar joints are the weakness.

My longterm concern with UFH has always been that it will be good for worms and bad for my bank balance, so you are talking my language here. However a little reading up on this subject leads me to conclude that passiv house aspirations of many here means that received forum wisdom deviates from industry norms. A builder told me last month that he puts 100mm of PIR his upmarket UFH builds. I will aim for 150mm though 120mm seems ok. This page says that 50mm of reinforced screed is ok and a high performance insulation sheet allows for 75mm. I have a total of 195mm to play with by default so I am not too concerned about all of this. Shaving 30mm off ceiling height is not a concern, internal doors will not be compromised providing my final floor layup is sorted before lintels go on and with m-spec ramps to figure out I am sure 30mm can be accommodated.

They are standard 7.3N. In comparison Stowell 7N blocks are 21Kg. 18Kg is typical and I found one example online at 14.5Kg. I guess the weight varies depending on how much recycled material is included. I purchased 6 blocks from Jewson in the week to model the course layup and those included a lot of glass granules.

Heavies. 19kg each

The order for 1300 block was confirmed Friday. Acting on the advice of my part time adviser I suggested a "direct delivery" with the BM when placing the order hence my blocks will arrive direct from the manufacturer at a keen price of £0.79 per block. No bad for my first interaction with a builder's merchant.

Right I need to up SAP calcs into next week's todo list. I had assumed that my plan to use aerated blocks for the inner wall coupled with 25mm PIR lined internal walls would give my SAP score such a boost only 120mm under the floor would be just enough.

I was chatting to a static caravan dweller this evening and he said just like sleeping bags, vans are manufactured in different grades according to expected season usage.

It is an unavoidable consequence of wind driven rain seeping through the facing brick skin apparently.

Ok. As a matter of interest why would it not be possible to up the PIR by 30mm to 150mm just before scheduling the screed contractor? Something to do with door thresholds perhaps?

Yes I feel the same, think 120mm just scrapes past building regs. I have been delaying doing serious number crunching on SAP calcs.

I am not sure I have enough openings to allow such a cavity tray clean up. My building control diagram depicts a similar upper dpm tray as shown in your photo though this could promote creation of a moisture bridge, I am sitting on the fence re. this choice..

I did wonder if water arriving at the bottom of a cavity would seep through a lean mix cement fill. Yes proper weep vents are to be included just not sure at the moment how to interpret NHBC advice on how high they should be.

You are a one-man national research institute into house building, the Government should fund you. That is high science to me.

Thanks. I am less troubled by the thought of soggy insulation beads at the bottom of a cavity than than cavity batts. The regs for cavity cement fill in footings and the newer requirement for such batts to insulate the edge of a block floor results in little clearance. The pro insulation beads material online claims that batts are more likely to wick moisture than beads.

Very few people understand how their car works even so they own a phenomenally power efficient and reliable manufactured product. Capitalism supplies what people desire and can afford. The first useful step towards decent quality houses would be to reduce plot costs in this country to french levels but that would necessitate scrapping the town and country planning act of 1947 and saying goodbye to this green and pleasant land. Such a change would also crash the financial system because it would put millions into negative equity overnight.

The scrum methodology can work with offshoring though it is more difficult partly because those driving offshoring are not prepared to offshore their own function to create truly autonomous offshore teams. Most offshoring is actually disguised virtual onshoring with remote management retained in the UK. Agile emphasizes the role small self sufficient teams and I say agile adoption should be reflected in office desk topology. It works best when you can swivel your chair around and say "hey you what do you think". Unfortunately those organizations who need it most corrupt agile out of the starting gate, the test manager wants 10 testers located outside her office and the chief database administrator wants to sit within of cluster of fellow database experts. Agile is team centric and this can upset traditional organizational hierarchies.

This is interesting and not a version of Scrum history I heard before. I can see the historical timeline and how ideas percolated through from auto manufacturing to software but in reality the sudden uptake of Scrum/Agile around 2010 had a different timeline and motive forces. Scrum grew out of the extreme programming fraternity and new technologies for test driven development. The agile manifesto was a anti-management rebellious movement that was a reaction to prevailing project management methodologies that had underpinned many software project failures. Later the Agile consultancy and training industry grew of this movement which necessitated a degree of historical revisionism because (1) the agile manifesto is too simple to support a training industry (2) the psychological traits of incumbent management do not like change or rebellion so claiming association with Toyota makes rebellion more palatable.

Sorry no, this is not the core problem. Car manufacturing and aircraft manufacturing have the same complex supply chains comprised of sub contractors. Poor housing building in this country is a peculiarly British thing when compared with our near neighbours. We need to identify where this nation specifically malfunctions before the problem can be resolved.

Standard human behaviour which is to find the optimum point between effort and reward. We should not be surprised. I used to think this but not any longer. It is said a nation gets the newspapers it deserves and I would extend this concept to say a nation gets the houses it wants. The light touch regulation of poor building practice is just a reflection of the prevailing national political desire of the people. At the end of the day we the house buying people of the UK are to blame.