Ed_

Some of these portable AC units can be simply modified so that the air intake is ducted outside too which makes it closed loop. A whole internet ecosystem of people doing it!

There is rebar yes. I don't doubt all that is necessary for this concept where the 2m section of retaining wall beyond the edge of the basment is structurally integrated, and it may be the best solution, but it can also be done by freestanding sheet piles for example, so I just want to get a feel for any other options. For example I could have a separate retaining wall for that 2m wide section using something like this:

I have a walkout basement as the house is built into a slope. I need to retain the earth between one side of the basement and an existing retaining wall on the boundary, approx 2.5m height of earth. My structural engineer has come up with a design which extends the basement slab and one of the basement retaining walls to the boundary. It just doesn't look quite right to me. My concerns are mainly: rain water splash back from the extended slab, particularly as there is a door threshold and external insulation/render with no ventilation cavity. thermal bridging (not too concerned as just one corner) This is the plan view: This is the section view I don't want to just say "I don't like it" because maybe i'm wrong and this looks fine to others. I will also get the view of the builder. I'm just wondering what the general thoughts are as to whether it is a detail that will cause issues in the longer term and whether there are any ideas for improvement that I could take back to my SE? For example, the cowboy developer next door is retaining the same earth with sheet piles bashed in using a digger bucket. Not an approach I will take but does show that there may be other approaches.

Rust bulks up much more than the parent steel, around 7 times, so rust always looks very bad. I'm not saying its not an issue, but don't assume it must be an issue based on how it looks. Concrete inhibits corrosion so it is not a given that there is corrosion under the mortar - is the mortar cracked at all? Rust expands so if it is rusted you might expect to see the mortar was cracked. 6m is quite a long span so it is likely that the beam is sized for the bending moment not shear force. BM is maximum at the middle of the span, shear force is maximum at the ends, so SF would be your concern here and it is likely the beam has spare capacity e.g. it is the middle of the span which is most highly stressed not the ends. Also your rust is mainly on the flange and the flange barely contributes to shear strength. I would definitely investigate further before cutting anything. If you scrape the rust off you can measure the thickness and compare to the nominal thickness. If it has lost only a small amount I would clean and preserve as best you can and then monitor. If you are concerned then the belt and braces approach would be to get a technician out to do some ultrasonic thickness measurements and then ask a structural engineer to redo the calculations with the new thickness measurements to check the strength. They could also advise on remaining corrosion margin and when to start worrying about it again. For preservation something like Zinga is ideal, and you can get a spray which might help to get into any tight corners.

Your house should have been designed to never form mold. F&B is popular for period houses so I imagine that is why they are cautious. Similarly I personnally would not worry about moisture affecting paint in a kitchen, i've just checked my kitchen smart thermostat (current 100+ yr old house, average to poor extractor over hob) and the humidity only changes a few percent during cooking.

I'm going to be building a Danwood house. Some things are flexible and other things definitely aren't and it is difficult to tell beforehand which will be which, they have a build system and that is that. I've attached a photo i took of the system in a completed house I visited.

Never stated, just drawings of panels, but only 4-5kw ish. If finances allow at the end of the build I likely will do as you suggest and try to semi DIY it, I'd just rather not have to do it as I want to keep options open.

I have a planning condition that I must submit a sap which includes solar PV in accordance with my climate questionnaire. Climate questionnaire says PV as per drawings. Drawings show quite a large array. I would rather not fit panels now, due to budget. The development one side never mentioned solar and has no conditions to have solar. The other side has the same drawings and climate questionnaire but no condition to have PV. All approved within a year of each other, so I don't believe that solar PV is a necessary condition of approval, just that I have messed up by promising more than necessary. A compromise would be to fit solar to my shed roof, much smaller array, easier and cheaper. AI suggests I do a NMA to alter the roof plans to reduce and reposition the array, then seek to discharge my condition using these new drawings and smaller PV array. My question is whether this is really a good strategy and whether it is even necessary. If I submit a SAP with a small array to the council will they really compare to the drawings and say it is not big enough? And will they really care if they are not on the roof as per the drawings? It all seems a bit trivial but I have no experience. Many thanks.

Thanks @Russdl that is great, it looks like a sensible detail and I'll probably tweak mine to copy it. That GRP angle will hopefully also deal with the issue identified by @craig. Thanks everyone, really appreciated.

No, I haven't selected a manufacturer yet, but thanks for the tip.

It is not finalised, but it is a combination of me and my structural engineer. The rationale is that it is a walkout basement and the detail between the basement and the timber frame that makes up the top two floors means I can only have 100mm of external insulation on my basement walls (unless I step it out below the plinth, which I don't like the idea of), which is probably not quite enough, so I'm bulking it up a bit with 50mm internal Insulation (it would be enough if it was all basement, but it's not enough for the sections which are above ground- about 50% of the wall area). Under the slab will be 150mm, just because, so there is probably no need for the 50mm internal insulation there except I'd rather thermally isolate the screed a bit more from the concrete slab as the walls will be colder than the floor. Does that make sense? All thoughts appreciated, it seems like the best compromise of quite a few aspects to me but I'm not an expert...

Thanks everyone for your thoughts, only just catching up. @craig whilst the compacfoam does rest on the EPS and concrete, the track of the sliding door is above only the concrete so the load path will be directly down through the compacfoam Into the concrete, the compacfoam will see no bending and the EPS will see essentially zero load from the slider. I could adjust the compacfoam so it is only on the concrete but I see no advantage to doing thay- the compacfoam should help spread any point loads from the sill. Or at least that's what I'm thinking, maybe I'm wrong? @Nickfromwales is the EPS the frame rests on integral with the slab Insulation? My concern is that mine probably will not be, and therefore may move somewhat Independently of the slab. And then I worry about the DPC, probably because I don't understand the detailing. @Russdl I'd love to see any more details of the GRP and it's fitting if possible.

I'm struggling to find a good way of mounting my sliding doors, given I will have 100mm of external wall insulation as the outermost part of my wall buildup: I think the door track needs to go over the concrete slab, for strength, which leaves me struggling to protect the 100mm of external insulation. An extended sill seams like the best idea, but I can't really find any of these being offered, perhaps i'm not looking in the right places? As drawn i'm envisaging a wide sill that bridges the concrete to over the insulation, sat on compacfoam for a bit of strength to spread point loads, with the sliding door track set ontop of that. However I can't find suitable sills and i'm not sure if this arrangement would still put undesirable forces through the external insulation, for example when someone steps on the sill. Are there any other ways that don't introduce big thermal bridges?

Having similar debates myself. My main concern is that door/window u values are, at best, much worse than walls. Given a heat source like UFH, which is uniformly distributed, it is inevitable that close to the doors/windows will be colder than the rest of the room, more so with large expanses of glass. So it seems to me that saving money on the u value of doors/windows might be economic in cost terms but possibly has a significant effect on comfort.

I can't raise the parking area unfortunately, right next to the house. I can probably just make it work with 1/80 fall, but it's very marginal, i'm having to design junctions very precisely and always wary that the consequence of an error anywhere is that it won't work. Does anyone have any experience of using ductile iron pipe? I've found a few things saying it can be buried shallow as strong enough to take the load, haven't found much detail and not sure how BCO will view it. Mesh bridging - do you mean to reinforce the concrete?