George

Is that how they describe themselves? An Architect is a protected title, and the other common professional is an Architectural Technologist. Architectural Designer is not something I recognise. However, construction is pretty unregulated when it comes to design - if you can be assured of their insurance and competence then you could use them.

Timber can be used but you'll need to contact a structural engineer to come up with a design. Solid timber can be hard to source and becomes unwieldy over 4m for most applications. Over that length a glulam or LVL (both types of engineered timber) becomes more practical. Steel is generally the cheaper option.

Ah, 203UCs, saving SE's bacon for generations. Two other options that may work: A pair of 203x133x25 UBs - similar steel weight to the 203UC but easier to handle on site, minimal extra fabrication but may be too wide - although I think there is scope to just shift the beams downwards on plan If there's a wall above to push the 254UB up into it (but I suspect there's a doorway somewhere along the beam span so that's no good) Anything else requires excessive fabrication/cost as Gus says.

Dig a land drain around the house at the top end to divert water away. And knock through a land drain at the low end to let anything that does get in, out. Makes a nice little run for the rats though. It shouldn't degrade the structure but trapping water is rarely a good idea.

It's either thumb pushing or a geotechnical investigation unfortunately (although I'd love to get a hand shear vane, it's only applicable to certain soil types and not much better than a thumb)

If there's no sign of cracking due to ground movement caused by soil shrinkage or swelling already, then I wouldn't anticipate a problem with swelling following a tree removal. That said, if you are definitely on shrinkable clays and the house has shallow (<600mm) foundations, then as a precaution you could have the tree removed in two hits. Remove 50% one year and the rest the following year.

Painted black it's not noticeable - stone/brick can't float so you need something there. Catnic has the right idea - multiple standard lintels to make up the width of the wall.

Classic method is to leave 75mm gap from the underside of exg foundation and once the concrete has cured dry pack (to minimise shrinkage) to fill the final gap In good masonry, 1000mm width pins. Shore the sides of the excavation to prevent collapse making the excavation wider. In poor masonry or stone, down to 600mm or less width. May need additional shims to support very poor stone (although very poor walls should be strengthened or aren't suitable for underpinning) but most walls can easily arch over 600mm. Hand dig / access only ever will a fully shored excavation and with measure to mitigate against masonry falling in. ASUC members are who to go to.

Better to have a timber wall plate fixed to the top. Otherwise you need to figure out a way of attaching X number of timber joists to a steel beam. Beam under the masonry can be packed out with brick and dry pack mortar - lot cheaper than more steel. Making beams bigger isn't necessarily straightforward, while in general deeper means stiffer, that is only definite in the major axis... they can be more slender which can be an issue with torsion resistance (for the bi-fold door underside plate) and lateral stability (for the beam below the wall) .

This is to help stop the gable falling over (because the roof trusses get installed so the gable wall can be strapped back to the roof trusses as it goes up). So it's done for a good reason.

Groundsworker was a bit sceptical but it's been there for three years with no issue. Floor is warm and no damp issues.

I've got 1.5m^3 spare in the West Midlands - yours for £100 (buyer to collect!)

What did the SE report recommend? I've never specced the polymers but have had various CPD lunches off them over the years. I've always had the impression they're done when nothing else is really suitable, so I would certainly look at conventional cement grouting or even if underpinning before opting for polymer injection. 2) Shouldn't be significant. May need to do a raft rather than normal footings but all achievable 3) If done properly, shouldn't be an issue. A ASUC registered contractor is a safe(r) bet 4) Not for normal repair. Crack stitching isn't always needed and can be counter productive on an old house. I wouldn't crack stitch the photo above

Just to check... The structural engineer has given the OK to cut a hole in the steel beam? 90mm is over a third of the depth which is the point I'd get a bit wary. Plus needs to be away from point loads/supports

I would recommend getting an engineer's advice. The overall wall height is 2.4m and is holding up your neighbour's land. The construction of the new wall has the potential to undermine the existing retaining wall so consideration of temporary works or staged construction will be needed. There's not enough detail on your plan but the reinforcement design will also need thought as there is the potential for some surcharge loading from the existing wall. Plus dealing hydrostatic pressure. Oh also, party wall agreement may be needed.

Oh I was commenting on the above post. Vibro-stone columns are what he probably had. Both VSCs and CMCs are displacement piles so they improve the ground - so yes this would avoid the thermal bridging as once the ground is improved, you could build up treating the soil as a competent strata. Definitely worth getting that looked at as an option and may have come about in value engineering anyway. The thermal bridge itself was probably pretty minor. Or you could have switched to a structural raft with insulation laid on top (this would be my preference in poor ground - even with VSCs, put down a structural slab then insulate on top). A decent thick screed would make up a lot of the thermal mass otherwise lost.

Vibro-stone columns? Often a good choice. CMCs are another option but fewer companies here have the rigs.

Best talking to the concrete supplier. You'd want it added in the batching plant.

The SUDS hierarchy is (there are different versions but broadly speaking): Rainwater re-use (rainwater harvesting/greywater recycling) An adequate soakaway or other infiltration system Hybrid solution of infiltration and discharging to a surface water body To a surface water body (e.g. an ordinary watercourse) To a surface water sewer, highway drain, or other drainage system To a combined sewer To move to a lower level on the hierarchy should need some justification. So if the two pipes cannot be connected to the soakaway due to unreasonable practical constraints, then you should still be looking for a ditch/landdrain/surface water sewer. If that's not an option then to a combined sewer can be done. A detail I've had to use in some circumstances is a hybrid solution with infiltration and combined system. That is, to use a soakaway but connect an overflow (lower than the incoming pipe but otherwise as high as possible) to whatever drain is feasible, even a combined. This allows low rainfall storms to soakaway (even clay has a percolation rate of something, plus it only needs to get to a fissures before joining the ground water easily) and in the event of a large prolonged rainfall, it can still escape somewhere. It's easy to think oh it's just one more drain, but a lot of it starts at the household level - we have a responsibility to not overload our sewers wherever possible since that is the main reason sewage gets dumped into watercourses.

It's only an issue if temperature will drop below 5 degrees and falling. If that's the case wait until temperature is 5 degrees and rising (ie the morning), use additives if needed and once the reaction is underway the exothermic component will keep things warm until the cure is well underway. Cold weather construction is a well understood issue but it does need to be dealt with properly.

Yeah I'd done the calculation wrong! I don't have a decent measure on ach in my house but making assumptions it'd be about a third of my heat loss.

The only time I've seen foil insulation suggested seriously is for retrofit where nothing else was feasible. The idea is that radiant heat gets reflected back into the room to be absorbed. Which is great. but with a well insulated wall, that same radiant heat is absorbed by the wall, so still remains within the same thermal envelope. So what have you gained by reflecting it back in? Foil can make make some improvement in badly insulated walls. But on a new build that is not where you should be. If weight is an issue, improve the foundations.

Internal to external wants to go from less vapour permeable to more vapour permeable. Are the internal battens for a service void? You shouldn't need plywood on both sides (personally I think internal is better) and grade 3 OSB is a better choice. Internal - plasterboard - 25x38mm battens / service void - vapour control layer - 25mm PIR insulation* - 9mm OSB** - 150x50mm*** timber timber structure with full fill PIR* - Breather membrane - 50x50mm battens (or 2No layers 25mm battens for vertical cladding) / ventilated cavity - cladding *Insulation type and thickness to whatever is needed for BR in your location **9mm OSB to be increased to whatever SE says ***150x50mm structure to whatever SE says

I need to discuss with Gus the role of brackets. I'm not a fan of online calculations but this is a decent summary of the issues https://beamcalc.co.uk/gallows-bracket-calculations/

I thought air changes were only be a small component of heat demand.