epsilonGreedy

I heard similar advice at the NEC show this year i.e. if trying to minimize noise then mount from a vertical surface instead of floor platform. Hanging off rafters sounds like the same concept taken further.

Concrete in the profile posts... not thought about that. Standard industry practice or is this a personal innovation?

I'm not convinced this is a positive. We are just highly evolved mammals conditioned by millions of years of evolution to snuggle down at night on a planet with diurnal rhythms, I am waiting for the NHS to discover "Passive House sleep deprivation syndrome" I can see this as a benefit in Spring and Autumn when coupled with solar driven energy capture. The biggie is coupling UFH to a lower temp heat source such as ASHP.

There is a moderate concern about a 1 in 30 year surface water flash flood risk and a recommendation to raise the dpc. Would this require many more cubic meters of concrete using a slab design? The science here seems to contradict the prevailing view that ground source heat pumps are far more effective than their air sourced cousins. Surely air has much less thermal capacity to draw away heat than solid ground hence this concern about a foundation air void soaking away a home's heat feels overstated. I do not share the current Selfbuild vogue for UFH, at least not from a financial performance perspective. Why charge up the humongous heat capacity of a concrete floor slab at 10 pm or 9am when the occupants of a house will typically be away at work or kicking off the duvet cover because the house is too warm to sleep comfortably. In my view UFH only works if a home's occupants are retired and the heat source is lower than 30 degrees i.e. not a gas boiler and the insulation level is so high 1Kw of heat will maintain a 20 degree heat differential and mechanical ventilation distributes heat around the home. I will not tick three of those boxes.

A new build on a green field site.

I would have thought that the income from a lettable holiday property would more than offset some extra borrowing to get the main house to a weather tight shell where you can then camp out. Are you subject to the additional pre habitation checks applied by building control in Scotland? 15 holiday weekly lets should produce a profit of £5000 annually providing the cost of creating a desirable holiday location is not crippling.

I think 15 Georgian wood windows including 10 sash windows makes a Passiv House an aspiration too far in my case. My motivation for interbeam insulation is that some variations have insulation blocks that wrap around and lock together under the concrete beams. I assume this saves a few inches in finished floor height compared to having 130mm of insulation laid above the beams. I am juggling with a planning limit imposed on the overall roof ridge height plus an already low upper floor eve height plus an enviro flood survey report recommendation to raise the dpc 300mm higher than is typical.

Hmm I am beginning to understand why beam and block is the default choice, this is not just a material, technology and insulation performance decision. The attraction of beam and block is that it permits a flexible build workflow that can tolerate adverse weather and/or a slow build hit by unscheduled delays.

What are you hoping to gain through the remortgaging process? I am confused since you state you do not wish to further extend your current self build mortgage and yet you cite an expected higher final valuation which sounds like the logic used to take on a larger mortgage. Presumably a single land title includes the finished garage with holiday let and the part-complete house in which case the present self build mortgage company will view the garage as part of their security. Is the holiday let fit for your personal habitation needs?

Is there a concern over rainwater ingress into an insulated screeded floor? I can imagine that a combination of a floor membrane under insulation sheets with screed over the top could trap significant rainwater ingress, then introduce frost freeze/thaw cycles = ouch.

I am trying to understand why screeding of a ground floor is delayed and often left to plasterers, maybe I am confusing floor leveling screeding with structural screeding over a block & beam floor. This question is important to me at this point because I am considering either a normal block & beam suspended floor or something like Jetfloor with large inter beam blocks of insulation. In the latter case I assume the structural screed is applied before the wall elevations reach 2 feet above dpc in order to protect the floor insulation as the build continues. If I do go for Jetfloor is there a some downside to having a finished screeded floor exposed for longer during the main build phase above dpc?

In my self build plan plastering is a personal no go zone, did you have prior experience?

After reading this I am beginning to favour the @ProDave self build workflow i.e. live on site and soldier on solo no matter how long it takes.

I am sure many reading this thread will appreciate that posting this salutary tale of woe necessitates the OP reliving a distressing period of their self build story.

Some how you have created a 2800 sq ft design without any wow features. I would incorporate a grand glazed connection between the hall and sitting room which would then draw the eye through to the rear garden and then ditch the current door. You need a statement bathroom upstairs, 3 utilitarian bathrooms in such a grand house is wrong and this will cost you when selling. The biggest problem is the tunnel like kitchen dining day area, the island and dining table linear arrangement amplifies this problem. With oodles of space to play with some interior design tricks of the eye will break up this space. Model the bedrooms with proper sized beds, those depicted look like 4ft 6 doubles.

I think clause 3 needs rewording to "allow temporary structures commonly featured on a building site to facilitate safe and secure erection of a domestic house or to achieve compliance with regulatory standards".

Should a request for weekly payment from a builder large enough to have an ongoing team presence on a job be a warning to any self builder?

@newhome When the builder denied hiring the worker I would have been temped to deny hiring him to build your house and then said "but thanks for the donation of a free shell".

When I look at the fees for test boring and soil sample analysis I feel like dig & discover might be the cheaper solution.

Those turkey macerators are expensive, will they reduce their quote for a foul drainage system? BoomBoom, its an old one.

I failed to measure that one, it is about 8 meters. I was more concerned with the house until a structural engineer at the NEC warned the garage is a building people can be expected to enter so I should not anticipate reduced foundation requirements.

In 6 months time she will discover WhatsApp and boys, then she will wonder why Dad spent 6 months building her a house for little girls. Two years from now she will ask "Dad could you convert the old playhouse in the garden into a band practice club house, you know something like the awesome garage we used to have".

Following a setting out exercise I now know one corner of my house is 13 meters away from a willow tree and after checking with the NHBC foundations app the trench fill depth has been established. The double brick wall double garage 5.6m x 7.2m is closer to the willow tree and I am thinking that rather than fighting ground heave with heavy duty foundations why not redesign the garage to flex. Is there any structural engineering precedence for this type of solution? My current outline solution is an oakframe timber clad structure which I assume could flex a bit without incurring structural damage. Under this would be relatively shallow trenchfill footings, let's say 1.0m laid as 4 independent quarters that could move up to 5cm independent of each other. Looking at oak frame garage examples it seems they all feature a brick dwarf wall and so I think the dwarf wall would need substantial expansion joints at the quartered foundation boundaries. Is my thinking leading me into a structural engineering fantasy land?

Warning duly noted. This worried me too. What is so different about handcut bricks that requires such a soft mix! I get the basic notion of degrees of hardness in mortar and that harder is needed below dpc but matching mortar hardness to bricks or blocks is not a technical concept I can comprehend. At the end of the day I will go for your and NHBC recommendations e.g. 1:1:6 unless the supplier of fancy bricks can offer a more convincing argument for very soft mortar. It was very noisy at the show stand and so not conducive to a deep techno Q&A session. One bonus of selecting hand cut bricks is that a prospective customer gets an offer of a factory tour & drinks in an region where rich Home Country people go for a long-weekend in a boutique hotel. Most likely. I am trying to comprehend the whole build in detail before I start so when the build clock starts ticking I will not be prating around exploring different options on site.

I am erring away from premix batched mortar since we last discussed this subject because the minimum site delivery quantities mandate laying 1200 bricks in 48 hours and this would be problematic for me.