ADLIan

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!!