From this reply I take you don’t have any experience in thermal calculations and modern building. The thermal envelope of the property heat loss has zero relevance to the location or size of the property.
Nah, I’m just MCS certified in solar and HP systems! The larger a buildings envelope, the greater the number of heat exchanges occurs with the extenal extremities (enviroment). Insulating the envelope is an important factor but, perhaps more importantly not all building can afford an A rating, whether that is by design or cost to the consumer. The larger the building, the greater the internal volume to heat or cool… The design, R value (inc floors), ventillation and solar control all play a crucial factor ensuring thermal comfort. Wrapping the building fabric with insulation, especially those that wern’t built to breathe, without proper attention to adequate ventillation causes issues in itself. You don’t mention local climate and why its important – What’s the temperature on 1% of the coldest days, the hottest, the humidity, the demand you require. Choosing a HP based on these extremities, rather than averges is important and often overlooked.
You would be able to provide your MCS number so this can be checked.
If you look on multiple Facebook and other site there are unfortunately many many installs by MCS registered companies and individuals that have provided “cowboy workmanship” its just a fact of this
industry.
Insulating your property is a choice, in most circumstances the occupier can’t afford not to.
For people with financial barriers and really high heat loss properties there are lots of free funding (I can only speak about Scotland) so it wise for all occupants and owners to research these routes, most of the funding is not means tested too.
For example we have had over 30k of funding and now our property generates us an income from this.
With regards to ventilation all highly insulated properties should be fitted with a highly efficient MVHR system like ours here is the a screenshot from how ours is performing right now as you can see there is a lot of free heat recovered with fresh filtered air supplied 24/7.