Ferdinand

True ... but the marginal cost vs extra heating bills over 20 years and so on ...

Have aerogel prices come down? if I have my numbers right, 100mm of external wall insulation ... one you have added the extra things such as render ... will not take you much beyond Building Regs basic standard. Ferdinand

The last one I did I drew all the bits on the walls, took the lecky round for 20 minutes, and he gave me a list of what to buy two days later! This is amenable to a bottom up estimate imo, which should be quite quick to do. More seriously, I would do this by reviewing my plan, perhaps with a highlighter, and break it down into sub elements that I can do by inspection or guestimate in my head, then add a bit extra, then either accepting that I would use more cable later (piggery?), or buying the extra reel from somewhere I knew I could take it back 2 weeks later - as you would with tiles. It is nice that cable lasts for years and years. Or deconstruct it in my head - eg for a 10m x 10m house with a 3 room x 2 room plan, I know that a ring main round them all will be 4 full runs one way and 6 the other way from counting walls basically regardless of room shape and qty of sockets except for eg wiggly walls, which is 100m per floor plus twiddles for back to the CU, 3m per time to go upstairs, 300mm per double for the loopout, 1m per double on the worktop in the kitchen, rooms with no power etc. I would write each sub element I can do in my head in a list, and then add them up and do a cross check of some sort. Then repeat for each type of cable. That is how I do skirtings - how many front to back inside walls + side to side for overall dimensions for an estimate, then match the mix against lengths of individual walls eg 3.6 4.2 4.4 to minimise small offcuts (add this list back up to check the numbers are about the same), add a couple of lengths to avoid an extra delivery cost which will usually cost more for skirtings due to minimum order for free delivery, and match list 2 against price lists to give me the lowest total. Slight watch needed eg for outside corners which can require extra 100mm or so of skirting to be safe if there are several. I would say any I miss out is because of things I have forgotten, rather than things I have miss-estimated as I know my room sizes and distances quite well. The highlghter on the plan is one way to avoid missing things. F

Wall u value is probably 0.25. Rockwool in the cavity, thermalite inner. F

So you are presumably in the market for Buildhub zinc roof offcuts ...

Clearly, as ever, you all need to consort with Hermione. "Detritus exeat. Statim."

Cheers. Splitter it is then. Unfortunately my tap is in the wall, and I don't even have one at the front.

Our family's last Ford was a Cortina Mk III L reg, and that *didn't* handle well. Which was why the next one was a Mk I Fiesta15 years later when I was desperate, bright yellow and known as Felicity by its previous owner. Sort of car that Florence from the Magic Roundabout might have, Though to be fair a Ford Cortina was not much competition for NSU RO80s, which followed it. When it was stolen they bailed within half a mile. F

Getting to grips. I think I am missing 1 - An extra outside tap to dedicate to the drip system, or splitter. 2 - A converter for normal hose to 6mm, to enable a direct water buttonnection. F

I am getting a prehistoric Arthur Dent feeling about this. Confirmed by yesterday’s Cricket. I also have a couple of pieces I made as part of my EP-something, including a measure-twice-reminder toolbox with the handles welded onto the wrong end of the sheet of metal that became the lid , so every so often you get a reminder not to make that mistake again when it barks the knuckles.

Brick and block. Inside the cavity insulation is block. Inside the house is some studwork, some block. F

Up early to work whilst it is a bit cooler, and cool the house by a few degrees for breakfast time, and I am wondering about purge ventilation. Hoping to drop the temp by 3-4 degrees from the 27C it was mainly at last evening. Is there (or has there been) any useful work on the amount of open window needed to cool a house down, or rules of thumb? This morning I have about 200mm x 600mm x 4 area (=.48 sqm) of open skylight (ie 600mm centre hinged open 200mm) upstairs, and a conservatory door open downstairs (=1.5 sqm ish), and it is going to have a noticeable effect. A couple of top windows would not be sufficient. It depends on the ΔT between the inside temperature and the outside temperature, and also the thermal characteristics and size of the house and the materials, decrement delay, thermal emissivity etc, time that it is open etc. Is anyone aware of anything? I am thinking of something as simple as the building regs rules about window area vs floor area for adequate light etc. My 'single data point guestimate' says 0.5-1 sqm of ventilation opening aperture per 100sqm of average storey floor area size should be enough. Probably. Cheers Ferdinand

Why? Are there not some lamp posts that need counting, or some baked beans that need eating with a cocktail stick, or something? Perhaps I will never understand..

An alternative would be Bifolds with a leaf size of say 330mm. With appropriate adjustments to the stud ... say a bookcase each side of the opening in the sitting area. F

Get a mixer, even if you eBay it afterwards imo. Mixing that amount of concrete by hand will be a learning experience.

Ok Problem fix. Half used soap falls through wire hangover soap dish. Solution is new kitchen scourer cut to size. if I were being posh, I would use one of the samples of walk on shower non slip matting I have.

Exempt under critique and review. ?

Vicissitudes of life. My Claber kit, being examined, went in about 15 seconds from the previous “not interested” to “Bwahahah ! Mine !” Pah. Need now to order some more bits for the management. It is like cats and a bag of crisps. Have been informed that a water butt and a watering can are entirely adequate for my bit of the garden. F

Tempted to say clear something so you can monitor. Do Osmo do one?

Possibly not quite the terminology intended ?. It is about understanding different ways of modelling similar things. However people have tried, and here is a recent one with an SS to which many variations of build cost are included by quite a few people. May be useful to build on this.

May be worth the mixer. Not expensive ... around 300 for a Baby Belle type, and save a helluva lot of work / time. And you get decent quality concrete / cement. Ferdinand

This is an interesting one, with a number of difficulties. There have been one or maybe two occasions on which this has worked on BH. The biggest issue is perhaps that we are a herd of cats spread out in time and space. My comments 1 - I reckon BH could perhaps have groups of size 5 - 30. That is too small to work by mass-bludgeon. Instead we need to supply a notable boost and/or other benefits ie treat them as our customer too. 2 - Any group buy needs to offer savings enough to cover the work of doing it, and to out compete what any individual can achieve by surfin' and lookin' . BH supply side is mostly about more appropriate products, cheaper individual sources for the same thing or alternatives who do not price gouge. This needs to be better than that for the cases where it is used. 3 - Effectively we need to find things where we can help the business take out cost from *their* process, add very little extra (ie manage there being 20 customers), and perhaps us do things they would normally do. 4 - Perhaps the group within BH (or an audience segment we could develop) would be around those who are slightly risk-averse ie not those of us who are wheeler-dealers. May be custom or PM-ing types rather than those of us who start with a tree and a quarry and a computer and do it all ourselves. 5 - We need suppliers who will play ball. 6 - We need suppliers where the product is standard, or BH experience suggests the supplier is reliable. 7 - We perhaps need to think in terms of other than money - eg making real slates affordable rather than relying on a Chinese import. One might be stabilising cost and reducing risk in markets which are volatile in their pricing. 3G or kitchens? 8 - What is there that is out of reach for most of us, but would come into range for a good deal? Quite a challenge. Think we need to focus on particular things within the self-build process. Which brings us to: eg Kingspan are not going to give us 30-40% off insulation by buying orders for even 50 houses. It would need to be a big reduction because you can get nearly that much off by just shopping around, and for say Kingspan we would need to put together a regional-developer sized long term order, and some way to make it like dealing with a very few customers. The counterparty risk for KS on a big enough order would negate the benefit. So I have this as my guide as to where this might work: 1 - Look for products or services where we can take cost out of *their* process, or be significant to their business. 2 - Suggests places where the cost of customer acquisition is high, the value / margin is high, the process is complex (and BHers - whilst being awkwards sods - perhaps know more than average so can save there), or a smallish group will add a significant chunk to their business. 3 - Things where a knowledgeable customers may be a help not a hindrance. 4 - Smallish suppliers where say 25 orders at once or 25 orders spread out over 6-18 months would be beneficial. Are there semi-craft businesses wanting a bit more turnover? 5 - Look specifically for win-wins. 6 - We need a mechanism to prove that BHers are BHers, so they are getting a known customer. 7 - High value / small size. Also well-defined so we avoid rejection risks. For me this is saying "not commodities" are the lowest hanging fruit. So where does that leave us for areas that may be amenable? My immediate thoughts are double glazing, front doors, some services eg soil testing, small suppliers or those with innovative products, product trials / research exercises, maybe house shells eg MBC or Scotframe, "luxuries" some of us want eg Sageglass, importers who could get a bigger wagon, smaller suppliers, helping create a simple and durable new House Management system, AliG swimming pools, unusual roofs or high quality rainwater goods? Plus windfall opportunities eg job lots of things. That probably needs the prices to be 10-20% of retail or less. Current example of this might be these. We may perhaps trigger some to offer "Buildhub versions" of their product or service. Think this will need to be an action-learning thing, as a route to create a template as to how to do it. Ferdinand

Is that not a game that anyone can play with any country? Though I would probably say that the UK is perhaps very eclectic in diet, even by Western European standards, if we manage to avoid the attentions of some of our aspirational militant beef banners. For Germany perhaps starting with the real brick-like black bread, or some of the more distinctive offal dishes, or the Germoline Pink Herring Salad. Horse, for example, is delicious and still I think common in France but unpopular here - and that is mainly a matter of fashion / prejudice. Put a hunk of horse in the fridge in a student house, especially say a named variety such as Dartmoor Pony, and it may have interesting results. (Apparently Asian supermarkets in Gernmany are the place for teabags). Ferdinand

A weekend thought about design ideas. Given an extra 1 sqm of space, where would you put it in your house for most benefit? Either the current house, or the previous house. I am exploring opinions on which constraints are most beneficial to release very slightly. I have three answers: 1 - To make a small hob a big hob with a bit of extra space at the side. 2 - Inside the shower, to make a shower cubicle into a walk-in shower. 3 - Into the staircase to change the angle from 42 degres to 37 degrees. The first two are spaces where we spend a lot of time in a small space, so the extra benefit is perceived often. The third is again making something we use multiple times a day feel more relaxed. Any other ideas? Ferdinand

@Onoff is a One-off. Kyrie eleison . (My iPad cannot even get liturgical Greek right without mangling it. Lord, have mercy ... since no one asked.)