Insulation issues in new build home

Netexporter

And would have added to the cost - say 15k possibly 20k with underfloor in a large open plan property.

I don't think having a heat pump in a new-build would cost all that much extra. The underfloor heating pipes would cost less than radiators and you've got to pour a screed, anyway. The hot water cylinder wouldn't be much different to one used for a gas system. If the house is properly insulated you won't need a very large heat pump. A 5kW Samsung costs about £2000, so not much more than a decent condensing boiler.

QrizB

Netexporter said:

And would have added to the cost - say 15k possibly 20k with underfloor in a large open plan property.

I don't think having a heat pump in a new-build would cost all that much extra. The underfloor heating pipes would cost less than radiators and you've got to pour a screed, anyway. The hot water cylinder wouldn't be much different to one used for a gas system. If the house is properly insulated you won't need a very large heat pump. A 5kW Samsung costs about £2000, so not much more than a decent condensing boiler.

Yes, it's easy to confuse retrofit costs with new-build costs.

Although in the OP's case, they don't have a gas boiler or radiators, just a bunch of panel heaters and a couple of towel rails:

• 3x MFP100E
• 3x MFP075E
• 2x MFP050E
• 3x TDTR350W

Per current retail prices at HeaterShop that's £1923 for the heaters and £777 for the towel rails, a total of £2700. I guess you'd be looking at closer to £8k for a wet system, so £5k more than what was installed?

Scot_39

OK my figures were probably retrofit - and as mainstream media - probably include a few K to bring insulaton - roof / cavity etc up to spec - which the OP shouldn't need.

The house has nominally 5kW of losses - if I read those with more knowledge posts correctly at the set parameters - - it currently has a total of 7.3 kW on a quick scan of table - panel and towel rail heaters - to overcome that.

Its clearly efficent so suspect doesn't need what some sites suggest a nominal fairly large 13kWh pump for a four bed - but it's unlikely to survive the coldest weather at times like this week in most of UK - with a 5kW output ASHP.

And certainly if the OP only expects to run heating part time to save costs - the way many run their gas boiler / thermostat settings you need higher powers (which often deliver powers in the order of 15-20+ kW as heat radiator fluid initially from cold after switch on).

Costwise - again retrofits

EDF use a typical figure of £13K - but a higher aver £15.4k (c6.9-8.9k after 7500 grant) for a 4 bed.

https://www.edfenergy.com/heating/heat-pumps/air-source-heat-pump-costs

Some indications of more detailed - albeit as you say - retrofit not new build pricing - can be seen for instance at

https://www.checkatrade.com/blog/cost-guides/air-source-heat-pump-cost/

Are you now saying the full downstairs area in modern homes are now concrete floor.  I thought it was only kitchens in older homes ?

But suspect your 2K is just the pump - add radiators, plumbing etc etc - and costs mount - even for a builder. 

It might be a lower figure than mine.

But in reality I am just making the point - there are no free lunches - if you want to save - you have to pay more for the right kit - to do so.

And in an efficient home - theres less savings to be had to offset the initial cost.

And for someone buying based on green beliefs - gas even if available on site - wouldn't really be an option. And pretty soon legally wont be an option - new connections defacto ban (environmental impact regs) kicks in c2025 iirc was proposed - and maybe actually passed in last couple of months.

And whereas the owners might qualify get the 7.5k grant - I suspect the builders cannot. So arguably it probably makes more sense currently to defer the decision to owners who want to fit to do so at a later date - rather than charging them all - and let the EPC "Very Poor" - guide them in that direction.  Not even sure if new homes would qualify - or any residency term - as the core £7500 is an "upgrade" scheme.

BellaBlondykeTheThird

Scot_39 said:

Panda126 said:

matt_drummer said:

That heat loss calculation means that the house will require a constant 5kW of heat to maintain 21c inside when it is -4c outside..

With those heaters that is 120kWh a day of electricity just for heating, plus DHW and all the other electricity consumption. An expensive house in terms of energy costs.

In the current weather you would expect to be using at least 100kWh of electricity a day on heating alone.

The heating needs to be on constantly otherwise the house will get cold.

What were the developers thinking?

Profit of course!

I am surprised that any local authority let them build like that, or maybe I am not surprised.

An alternative heating source is required. The heat loss isn't terrible for a house that size so there's little prospect of reducing the heat loss much.

It could well be that the heat loss is actually greater than calculated if it has been poorly constructed.

A heat pump would reduce the heating cost to a third of that as a minimum, even less if done properly.

A gas or oil boiler is the next alternative if possible? Is it allowed in a new build?

Otherwise night storage heaters.

This is ridiculous. It's like paying another mortgage!
We had no idea how to read this report so thank you for helping us to understand it. 
We would never buy this house with this knowledge. We feel like we've been lied with their promises of eco cost effective house

In turn from bold above 
Profit of course!
No builder is going to fit expensive heating and then not reflect it - with potentially large profit - in their costs.
Many are not shy of the concept - one iirc reported profits of c£60k per home completion couple of years ago.
A heat pump would reduce the heating cost to a third of that as a minimum, even less if done properly.
And would have added to the cost - say 15k possibly 20k with underfloor in a large open plan property.
The epc says c7400kWh - that's c £2100 at svt - less on OPs Octopus tracker.
Many ashp may not be done properly - given sone posts here on winter performance - but let's stick with a third - that's a saving of c£1400 pa.
Less than a 10th of the likely impact on purchase price.
Were the OP and his neighbours willing to pay that extra 12k+ upfront in their deposit or via mortgage vs panel heaters ?
On a smaller property 1 or 2 bed in a cheaper area - say c150-200k how many purchasers could afford / qualify for the mortgage on the extra £10k for  a simpler wet install etc.  With an even lower potential energy cost saving as pay back.
Or worse repay it over say a 25-30+ year mortgage - which could see it doubled at current rates - so in effect 15k becomes 30k - so over or £1000 on annual payments regardless.

This is ridiculous. It's like paying another mortgage!
Coventional Electric heating is expensive. If your used to mains gas on a like for like basis - very expensive. 
That's the reason green lobby and now govt via grants are pushing ashp - to close that running cost gap - when ecouraging - soon to be forcing - dropping household emissions as aim to hit net zero.
But suspect you knew the heating fitted - it would be strange not to these days.  And the "very poor" on EPC should have highlighted it to you to think and find out - before completion. 
And as above - you would very likely have paid via purchase price instead anyway.
Now you have the choice.  But granted that can come with potential disturbance like fitting radiator pipework in a finished property etc.

From other posts 
1) EPC Estimates vs UK nominal Ofgem averages 
You have an EPC that tells you it could cost c7400kWh to Heat your home and water to some nominal level annually.
That's a fraction of the Ofgem cap in media headlines for years now.
The headline figures in media  - are based on now lower 11,500 kWh for gas (was 12,000kWh) - but if take 3kW+ per day for gas cooking - that's still over 10,500 kWh.
Not only is that 10,500 kWh much higher - that's also for a smaller home - iirc for a medium use profile - Ofgem suggest thats nominally for 2-3 bed - 2-3 persons.
And the Ofgem "high" consumption band duel fuel gas TDCV - one less published in media - for larger households / homes  - a much higher 17,000 kWh. 

So in that case well over double your large 4 bed properties 7,400 kWh EPC figure even allowing for gas cooking  and double even allowing for modern boiler losses.
So see no reason based on above and others comments on your loss certificate etc to dispute the promised sales glossy literature that the building standard as promised had - very good as EPC puts it - losses so eco creditionals. 
Assuming it meets them of course.

2) Running Costs
7,400 kWh at typical single rate electric DD svt average = £2,100 pounds for hw and heating (ignoring other non heating costs).  Less on likes of tracker in past months or agile tracker rates if time shifting.
You need to stop being to some extent being distracted by £s on winter bills per se and get back on topic anyway. And should not be overly extrapolating cold snap billing levels to annual overall cost estimates anyway.

And the kit needed to save on bills - as above costs £1000s if not £10,000s for a house your size (£15-20k figures are floated regularly for wet ashp from scratch for average properties). 
You have to invest to save on default - many of those posting here who pay least for heating - have invested very heavily - some I supect well into 5 figures to do so.
Let a builder load that kit into price - you could - as above - not just be paying for it - but  be paying near double on mortgage over lifetime anyway. And personally not sure I'd trust some to fit the best solution and fit it well.
Your well known brand panel heaters might have cost c£2.5-3k in total by comparison. They could have been even cheaper models.

Overall Id recommend getting back to your original root question and focus on external heat losses.

And any issues where shoddy build - has compromised the promised levels.

So gaps in insulation (invisible to you if) internally to walls and roof insulation or seals etc around fittings like doors windows and drainage outlets.

That is overall 

Do your external wall, roof and windows and associated insulation where required - meet the promised heat efficiencies.

I think some of that was legible.

Heat pumps, over wall radiator pipes and a cylinder do not cost £15-20k supplied and fitted but will look ugly in this new house the OP has purchased.

Maybe they could get planning permission for the air conditioning multi split systems to heat the rooms you use most. Aren't they vat free at the moment or am I making that up.

The OP already has a heat pump hot water system so the hot water will be cheaper than the EPC suggests.

They also have solar to take the sting off the bills and Agile. I doubt with an export of 15p kWh in the summer they will have much of an electricity bill for the year even with what they have. Maybe £100-£120 a month.

I suspect if the other neighbours are not all up in arms on the same development they have already run the numbers and worked that out.

Sounds like the OP could do with some advice.on how to use their circa £300 thermal camera they bought (that's maybe a quarter of their annual electriciry bill gone.

Scot_39

Sounds like the OP could do with some advice.on how to use their circa £300 thermal camera they bought (that's maybe a quarter of their annual electriciry bill gone.

Lending it (even for a small charge) to the neighbours might be a good idea - to see whether the potential cold spots in one plot are repeated in others.

JSHarris

My best guess is that this is a combination of missing insulation plus cold air leaking in.  If the internal walls are dot-and-dab plasterboard then it's very likely that cold air is flowing behind the plasterboard.  This is such a poor method of finishing (but is very cheap!) that it's colloquially referred to in the trade as a "plasterboard tent" (because it has about as much insulation effectiveness as a tent).

It's a sad reflection on the UK construction industry that breaches of building regulations are completely normal and widespread.  I've done many energy surveys over the past ten years and the stand-out point is that houses built in the past couple of decades are often the very worst in terms of thermal performance.  This shouldn't be the case, as building regulations have got much tighter, but lots of developers cheat and don't comply with them.  There is no independent verification of compliance with building regulations for mass developers - they can not only effectively assess their own work*** but they also only need to check a small percentage of the homes they build, as compliance doesn't require 100% inspection of every home.  This means they may well build a few fully compliant homes on a development but will ignore the regs for the majority of the others.

*** For the pedantic, they don't literally "mark their own work", but do in effect.  Since building control has been privatised all those companies competing for the work strive to keep their customers (the developers) happy.  If they don't then they may not win the next contract.  The result is that there are a lot of blind eyes turned when it comes to not spotting airtightness or insulation deficiencies.

I've just dug out a thermal image taken of the area above a window where there was cold air leakage behind dot-and-dab plasterboard, resulting in an area of high heat loss.  The pattern is similar to that in the earlier post and is fairly typical of the sort of defects found in many homes built over the past couple of decades: