ADLIan

To clarify, above standard is for blown in mineral wool. No equivalent* Standard for eps beads but same BBA standard and test methods for manufacture & install *there is an equivalent BS! BS EN 16809.

This work is notifiable under the building regs. At the least the manufacture and install should be in accordance with BS EN 14064. Product needs to be CE/ UKCA marked as there is a designated/harmonised BS EN. Not sure how you would even confirm the thermal conductivity, once installed, of random beads bought from eBay never mind all other declared physical properties and weather resistance. Building Regs require these products to have 3rd party certification (BBA or similar) for both the manufacture and installation. Approved systems installed by approved contractors are generally deemed to comply with the Approved Doc without a building reg application. In short DIY is a non starter.

Do NOT inject any insulation in the cavity between a brick/block outer and the timber frame. Simply not a recognized system/method of insulating walls. Cellulose cannot be used in external masonry cavity walls.

Remember SAP is not intended to be a deign tool for the space and water heating systems.

A = GF area. P = perimeter length as you look at the plan view. In above 36m (not 3.6m, no thickness involved). P/A for most houses is approx 0.4

Is Ubakus treating this as a suspended ground floor? Does not appear to be.

Therm won’t do it as it’s a 3D analysis rather than 2D.

Back in the early 2000s (cannot remember exact dates) there was a loophole in the Building Regs that allowed the efficiency of heat pumps to meet the CO2 emission standards whilst allowing cr*p levels of insulation and airtightness perhaps as bad as the backstop values. Heard of developers using this method and dread to think what bills the house owners were left with. The additional costs, compared to gas heating, was very obvious in the EPCs.

Bear in mind blown in cavity insulation (new build or refurb) is notifiable under the Building Regs. Product should carry 3rd party certification (BBA or similar) and be installed by approved contractor.

Can be modelled using 3D thermal modelling (not THERM) but frankly it's such a localised and discrete piece of metal and no doubt will surrounded by insulation it's not worth worrying about.

Thermal Mass is actually 'thermal mass parameter' used within SAP. Based on the heat capacity of internal linings (kJ/m2K), area of each element and total floor area. In older versions of SAP it was broadly classified as low, medium or high depending upon construction method but now has to be calculated more precisely.

Heat loss from (cavity) party walls has been in the Regs for many years - all linked to air movement within, into and out of the cavity. Fully filling with mineral wool and sealing the wall edges are deemed to give zero U-value. Description here

I'm not sure exactly what is being shown there. The 'baseline' may be the 'notional' building used as the benchmark to compare your actual proposed dwelling (see Table 1.1 in AD L1). As mentioned before the Planners will look at this very simply (unless they have more detailed requirements which is doubtful). The important numbers are those for your 'proposed' house - a 40% reduction in the DER here is normally sufficient for the Planners. I note the main fuel is electricity do you have lots of solar PV or using a heat pump to get the CO2 emissions down?

Planners make up these rules but haven’t got a clue what they are actually asking for. In the absence of specific guidance from them if the DER is 40% better than TER then box ticked, move on…. Your SAP assessor is just confusing the issue, how you get the 40% uplift matters not to the planners.

Generally a masonry cavity wall (insulated or not) should not be ventilated - nothing to do with reducing condensation risk. A open cavity must be sealed at the top and must not link with any ventilation into the roof space/roof ventilation route - it’s a fire safety issue.

Ursa acoustic roll - heard it’s a great product, better than many similar and nicer to use

Loft insulation will effectively do the same job acoustically but should not be used as it does not have the correct mechanical properties to be used in a vertical application. Additionally Building Regs ask for a minimum density of 10 kg/m3 most loft insulation is probably a bit lower than this. Beware as denser does not equate to better acoustic performance once installed!!

PUR insulation does contain artificial blowing agents that give the product an enhanced thermal performance and yes this does leak out over time reducing the thermal efficiency. Check the thermal performance of foil faced boards against that of tissue faced flat roof boards. Foil faced is always better as it delays the escape of the gas. The test method for the thermal conductivity accounts for this with an artificially accelerated aging process prior to testing so quoted values are acceptable longer term.

The heat loss from a ground floor depends upon its size, shape, edge condition and ground under it. Assuming your floor is a simple rectangle it will have a u-value of approx 0.65 W/m2K without any insulation. Try inputting this value into the heat loss spreadsheet

The report doesn’t cover rendered brick/block wall as it covers worst case scenario of pretty poor quality brick outer. It was also a study to ensure the BBA test rig could still be calibrated and used.

NHBC requirements always trump BBA Certs. That’s just the way it is!

Plastic retaining discs that fit onto the wall tie will do the job. Standard practice.

No it isn't - call the manufacturer for advice. Surprised you're using 37 grade, would normally expect 35 or even 32 under current Regs

The BRE is a commercial body and will want payment for a new set of Accredited Construction Details - I doubt the Govt is minded to fund this sort of work. There is no need to be 'accredited' or 'approved' to undertake psi-values - the requirement is simply to be 'competent' - a discussion to have with your BCO (if he knows what a psi-value is!). Will be interesting to see what the BRE have to say.

Manufacturers offering psi-values will obviously promote their own products. The 2D thermal modeling of the junctions is time consuming and complex - I undertake them for the insulation company I work for as part of our technical and sales package. The problem with some current psi-values is to be acceptable under the current Building Regs and SAP 10 they must be done to the 2nd edition of BR497. Many older values were to the 1st edition and these can only be used for the previous Regs and SAP 2012. Note photo evidence is now required for many aspects of the build so the Regs have tried to close this loophole. I cannot say how successful this is or will be as I'm no longer an accredited SAP assessor. I baled out as I would be spending too much time chasing for these photos and other evidence and then being cast as the bad guy when they're not available (which is a BR failure!) or show a different insulation/thickness, etc, etc and the 'as built' potentially fails.