Insulation issues in new build home

Panda126

QrizB said:

Interesting that they've calculated 664W of heat loss from the utility room but the only heat source is a 350W towel rail! That's never going to work.

Your bedroom has a 750W heater which is slightly larger than the bedroom 1 heat loss of 681W but the excess of >70 watts isn't going to get you up to temperature quickly. Adding two adult humans to the room will be an extra 100W or so (more if you're doing something active). That shows how slim the surplus is.

Are the heaters in the other rooms just as marginal vs. the heat loss calcs?

Edit to add: I can't find the numbers but I think my bedroom is a similar floor area to your Bedroom 1 and has a 1kW radiator. My ground floor is mostly open plan and has four rads, totalling 6kW or so.

We actually modified the floor plan by extending the wall in WC and making the utility a bit smaller and it's my office now. Here's the list of radiators installed in our house.
 We had no idea about the costs as we've been told the house is 'modern, ecological, and cost-effective', and offers ' most modern approaches to reducing

energy bills'

matt_drummer

MultiFuelBurner 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.

Remembering from their other post they have a heat pump water heater but I couldn't work out if they could utilise that system any further with a heating engineer. They will have to get someone in.

As you found out with your install they have one external heat pump type box outside so initial thoughts of additional heating through air to air heat pump multi split system to the main living areas and bedrooms will probably need planning permissions.

On the other thread we also advised they would have to leave all radiators on to heat the fabric of the house and leave them on to gain the temperatures they needed.

They were also informed to talk to their neighbours on the same development and consider some group action, so far the OP hasn't said if they have progressed this.

Air to air actually requires planning permission in all cases as it is also capable of cooling.

The wording actually says `used for cooling' but it is probably difficult to prove that it isn't, or maybe difficult to prove that it is.

That is the law, how widely or strictly it is enforce I do not know.

Panda126

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.

MultiFuelBurner

matt_drummer said:

MultiFuelBurner 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.

Remembering from their other post they have a heat pump water heater but I couldn't work out if they could utilise that system any further with a heating engineer. They will have to get someone in.

As you found out with your install they have one external heat pump type box outside so initial thoughts of additional heating through air to air heat pump multi split system to the main living areas and bedrooms will probably need planning permissions.

On the other thread we also advised they would have to leave all radiators on to heat the fabric of the house and leave them on to gain the temperatures they needed.

They were also informed to talk to their neighbours on the same development and consider some group action, so far the OP hasn't said if they have progressed this.

Air to air actually requires planning permission in all cases as it is also capable of cooling.

The wording actually says `used for cooling' but it is probably difficult to prove that it isn't, or maybe difficult to prove that it is.

That is the law, how widely or strictly it is enforce I do not know.

Not where we are you are allowed one outside system for auxiliary heating, maybe because we are rural with no gas.

But as we said on the other thread it would probably need planning so that was already covered there.

matt_drummer

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.

The house is not the problem.

My similar sized house needs 4kW to 4.5kW constantly to maintain temperature.

I give it just that using an air source heat pump and radiators.

I could turn it off or down at night but then I would just need more heat the next day.

It seems like your heating has no excess capacity to raise the house temperature very quickly, therefore, if you want it to stay warm you will need to add heat constantly.

That heating system will always be the least cost effective heating system, it uses electricity at an efficiency of 1 to 1.

Electricity is about four times the cost of gas so your heating is the least cost effective by a factor of around four.

It's also not very eco, it uses 1kWh of electricity to produce 1kWh of heat.

An air source heat pump produces three to six times more heat from 1kWh of electricity.

You have been lied to on both counts, it's certainly not cost effective and although you are not burning anything somebody else is to generate your electricity so it's not very eco either.

I think you and your neighbours all need to get together and formulate a plan.

QrizB

Panda126 said:

Here's the list of radiators installed in our house.

If my mental arithmetic is up to scratch, that totals 7.3kW. So in principle, if you turned them all on, you could deliver the 5kW of heat input required to maintain 21C when it's a steady -4C outside.

matt_drummer said:

It seems like your heating has no excess capacity to raise the house temperature very quickly, therefore, if you want it to stay warm you will need to add heat constantly.

Exactly, 7.3kW of hat input vs. 5kW of loss is not a big margin. Particularly since electric heaters rarely achieve their nominal rating over the long term (and putting towels on a towel rail reduces their output).

But as Matt says, to maintain 21C in -4C weather you'd need 120kWh a day, which would cost you about £34.

And recently it's been quite a bit colder than -4C, at least some of the time. The thermometer in my back garden got down to -9C during the last week. RAF Benson (EGUB at Wunderground) saw -11C.

MultiFuelBurner

Was this in any literature 

We had no idea about the costs as we've been told the house is 'modern, ecological, and cost-effective', and offers ' most modern approaches to reducing

energy bills

At this rate to get your house up to temperature you will burn through £40 of electricity a day just on heating. Adjusting for some milder days over winter and the colder months £5-6k on heating alone.

I can't remember if you said in your other thread. How many houses in total on this development?

Surely you can group together they must have realised how expensive things are by now? 

Panda126

MultiFuelBurner said:

Was this in any literature 

We had no idea about the costs as we've been told the house is 'modern, ecological, and cost-effective', and offers ' most modern approaches to reducing

energy bills

At this rate to get your house up to temperature you will burn through £40 of electricity a day just on heating. Adjusting for some milder days over winter and the colder months £5-6k on heating alone.

I can't remember if you said in your other thread. How many houses in total on this development?

Surely you can group together they must have realised how expensive things are by now? 

This is taken directly from their brochure and Zoopla. 
There's 25 houses and everyone is complaining about heating.

QrizB

MultiFuelBurner said:

Was this in any literature 
We had no idea about the costs as we've been told the house is 'modern, ecological, and cost-effective', and offers ' most modern approaches to reducing energy bills'

See their other thread.
Specifically this post, and the brochure they screencapped.

"State-of-the-art green building technology allowing for reduced energy consumption" giving "clean, green, affordable and comfortable living".

MultiFuelBurner said:

At this rate to get your house up to temperature you will burn through £40 of electricity a day just on heating. Adjusting for some milder days over winter and the colder months £5-6k on heating alone.

Maybe, maybe not. £6k would be over 20,000kWh of heat, which is getting on for double the "average". And as Matt has pointed out, a house with a heat loss of 5kW is not unusual.

Probably closer to £3k for the year. EDIT: They're on Agile, so the average price is closer to 20p/kWh than 30p/kWh. So £2-2.5k would cover 10MWh of heat.

A correctly-configured heat pump should reduce that to £1k or less.

OP just out of interest, what do Octopus offer you if you ask for a heat pump quote? (I know Matt has opinions on Octopus heat pumps, but as a quote engine it's quick and easy.)

https://octopus.energy/get-a-heat-pump/

matt_drummer

I think you need to get together.

Approach everybody you can, your MP, your council, the NHBC, anybody you can think of.

It's a disgrace that somebody thought it was OK to build houses with this heating.

It may not have been so bad a few years ago but surely there isn't a person in the country that doesn't know that energy costs have risen dramatically over the last three years.

It's a permanent financial penalty for buying one of their houses.

I really feel for you, it must be a nightmare.

But there is no point trying to live with it, one way or another it has to change.