Johnny Jekyll

That's good to know thanks joe90. We are doing the same thing, aiming to do our best but not strictly going for passive house.

Thanks

Thanks everyone. This is all great stuff. @gravelrash did you buy them from orlitech.co.uk ? Anyone specific to talk to?

All understood guys thanks.

Any opinions on basalt wall ties (Teplo) versus normal wall ties? They seem to be much more expensive, so worth the investment? If so, best place to buy them? And do they generally just replace existing wall ties i.e. same amount in same positions? Thanks

Thanks Jack

Thanks Peter

Also may I ask, in terms of UFH kits, are there any preferred manufacturers / suppliers? E.G. ProWarm / Wavin / Thermoflow / John Guest / Polypipe / Nu Heat? Or are they all pretty equal in terms quality? Are cheaper alternatives just as good?

Thanks very much Peter. May I have your opinions about ASHP noise?

Thanks for explaining.

Thank you, sorry what do you mean 'modulate down enough for a low energy house'?

Thanks for replying. Any thoughts from others with UFH systems? We are also considering using UFH with a traditional gas boiler system?

May I ask for your educated opinions on whether we should go for underfloor heating or a traditional combi system. First to paint the picture. We’ve started our first self-build in South London, a small 3 bed detached house (total of 130 square metres across two floors), which includes a family bathroom, a master bedroom en suite bathroom and a downstairs toilet. Foundations are already laid (before the pandemic hit which then paused the project), so we are out of the ground at least. The floor make-up is essentially the 375mm reinforced raft foundation outlined above, to 1200 gauge DPM to 150mm PIR T&G insulation to separation DPM to 75mm screed to hopefully vinyl floor finish. The walls will be 100mm medium dense blocks (both inner and outer to render outside) with 100mm PIR Cavity Therm full fill insulation. The loft insulation will be 300mm of wool rolls at ceiling level. Although we are not strictly going for Passivhaus, we are aiming for high levels of air tightness using membranes and tapes and installing an MVHR system. So overall a decent spec. We are stuck on the heating system though. We originally brought into the idea of downstairs under floor heating throughout (installed within the 75mm screed) and upstairs radiators. And to potentially use an air source heat pump and even 4kw PV Solar on the south roof. But after leaving the project alone for a while, we are now thinking is that really the way to go? Pros of ASHP and UFH include no radiators, even heat and warm underfoot. Cons of ASHP and UFH include more planning and specialist installation (time we don’t really have), more space for all the system bits (space we don’t really have), greater costs (even with the upcoming 2022 £4k clean heat grant after RHI), noise from the ASHP, time for the slab to heat up and cool down, likely greater maintenance due to more system bits. The question is should we go with a traditional high quality smart controlled combi boiler instead e.g. Viessmann with nice rads? Even the best stuff will be quite a bit cheaper. We can hide all the pipework within the walls and posi-joists. The installation is more straight forward with no water tanks or peripherals and saves space. And we don’t need to spend the time understanding the technologies or asking dozens of questions. Your experiences and independent opinions would be greatly appreciated. Also, we do like the look of the new Marley SolarTile integrated PV solar roof system (don’t know if anyone has used or seen them). We would need PV Solar to get through the SAP Calcs anyway, and the installation costs of such a system would be offset by not needing to install all the additional clay tiles and associated labour on the south roof. Thanks very much.

That's good advice thank you.

No probs thanks

Thanks, how much was your report may I ask?

I have spoken with my building inspector over the phone for the first time, for my self build (detached 3 bed, built up area with houses all around). They have asked for my Soil Investigation Report. I did not think it was compulsory to produce a Soil Investigation Report for a single self build property? Do I need to produce a report if my inspector requests one? Or can I explain that it's not compulsory and provide a British Geological Survey map for my location? Any thoughts or experiences, thanks.

Ah yes : o ) thanks for your help tonight. Very kind.

Sorry Nick what does PH stand for?

Understood great thanks

Thanks for the help. I'm using full fill insulation using Cavity Therm. Is it possible to vent at ground level where the final main soil pipe runs out to the sewer? Or must the vent to atmosphere be at the end of the run where the rear bathroom is? In other words is it possible not to vent upwards where is rear external pipe is? Sorry real novice on this at the moment.

Sorry my plumbing know how is not great yet. I will try and explain. It is the furthest / last soil pipe in the run so I'm told it will also extend up the wall minimum one metre past the windows, and I presume be ventilated at the top. Does that make sense?

We have a 1st floor bathroom to the rear of our new build and we have decided to exit the soil pipe through the building envelope straight away at that point and drop it down the outside wall, rather than internally dropping through the living room. Apart from sealing around the exit hole for air tightness, should I insulate the soil pipe at all (inside or outside)? Will I be causing any big thermal / cold bridge doing it this way? Thanks very much.

@newhome thanks very much will have a read, cheers

Hi everyone, may I have your opinions on my updated wall build-up (from in to out), thanks very much. - 3mm skim - 12.5mm plasterboard (fermacell (strength) / aquaboard (wet) where needed) - Battens for service voids (25mm - 50mm depending what services are running where) - Pro Clima Intello Plus membrane held against the wall by battens (fully and meticulously taped of course, this will envelope the entire inside of the building) - 100mm 7.3N Forterra Thermalite Aircrete blocks - 100mm full fill cavity using Cavity Therm by Xtratherm as it can achieve 0.2 U Value at this thickness - 100mm medium block - 15mm render