Insulation issues in new build home

Panda126

Oscarmax said:

Panda126 said:

Hi everyone, some time ago I raised an issue about our electric radiators as we were not able to keep our new house warm.

We did a couple of tests, and we figured out that there might be another issue which is the insulation.

Our house is losing heat ridiculously fast, for example we can heat up a room up to 20C. The moment we turn off the radiators our temperature starts to drop. We calculated that it is dropping by 0.5C every 20-25 minutes. And with the radiators off the temperature will keep dropping constantly (the lowest we saw so far was about 6C – yes, 6C inside the house with all doors, windows and vents closed)

As you can imagine our bills are very high, and this is with living in a house that is never warm no matter how much we spend on heating.

As it’s a new build house, built last year we never expected anything like this.

We contacted developer who can’t see any issue and told us the house is well insulated.

We continued to look closer at the issue. We invested in Topdon TC005 thermal camera, and what we saw shocked us.

It seems that we have a lot of cold spots in the house which from my understanding might suggest poor insulation, or no insulation at all. All outside walls seems to be very cold (they’re super cold when we touch them as well) but there’s a lot of cold spots in the ceilings as well.

I’m attaching photo of some examples of the cold spots we located in our house.

Does anyone have any experience with poor insulation in new build houses? Can someone advise me if we’re right thinking that the insulation is an issue in our home?

In 2017 we purchased a new detached bungalow, the wall cavities were supposed to be foam filled, we had to have several on the external brick replaced, we noted in places the foam insulation was missing, fitting the TV ariel in the loft we noticed the majority of the insulation was missing, the service valves were missing on most of the appliance, they fitted TRV valves on radiator near the thermostats, the majority of the electric sockets and light fittings had no earth insulation wire, the list was exhaustive.

The previous site manager was not up to the job, fortunately I was a building surveyor and had a good working relationship with the new site manager, I read the builder the riot act, the builder promptly apologised and put everything right.

The problem is that our builder can't see any issue and is avoiding any contact with us.

Panda126

I've been monitoring the utility room and the bedroom above today.

Heating was on for 5 hours. Set for 20C 
 
2pm
Utility - temperature when switched off the radiator was 16.4C after heating it for few hours.
Bedroom above - temperature when switched off the radiator was 18.1C after heating it for few hours.

3pm
Utility - temperature dropped to 14.5C
Bedroom above - temperature dropped to 17.1C

4.30pm
Utility - temperature dropped to 13.7C
Bedroom above - temperature dropped to 15.8C


The rest of the house is set on 18C (radiators on all the time) 
Outside temperature is 6C

In these two rooms heating was off for 2.5h

Temperature drop in utility: -2.7C
Temperature drop in the bedroom: -2.3C

It drops 2x faster than it's heating up.

Even if the heaters are not powerful enough, surely the house should keep the warmth for a bit longer? 

MultiFuelBurner

You say heating was on for 5 hours what were the starting temperatures for the Utility and Bedroom that you monitored?

And what rating in kWh of heater do you have in both rooms. This will aid heat loss calculations.

I am surprised at 5pm you had an outside temp of 6oC today but let's go with that. Was that taken from.a local weather station?

Panda126

MultiFuelBurner said:

You say heating was on for 5 hours what were the starting temperatures for the Utility and Bedroom that you monitored?

And what rating in kWh of heater do you have in both rooms. This will aid heat loss calculations.

I am surprised at 5pm you had an outside temp of 6oC today but let's go with that. Was that taken from.a local weather station?

Starting temperature in the utility was about 12C and bedroom was below 15C

Radiator in the utility room(about 4-5m2) - Dimplex towel rail 350(W)
Radiator in the bedroom(11m2) - dimplex Monterey (750W)

I didn't measure the weather outside, just looked at the temperature in my area. It was very sunny day with temperatures in range 5/6C.

We raised the issue with the developer regarding the radiators being not powerful enough and we've been told that these radiators ' far exceeds the heat loss for the space'.

Oscarmax

Panda126 said:

Oscarmax said:

Panda126 said:

Hi everyone, some time ago I raised an issue about our electric radiators as we were not able to keep our new house warm.

We did a couple of tests, and we figured out that there might be another issue which is the insulation.

Our house is losing heat ridiculously fast, for example we can heat up a room up to 20C. The moment we turn off the radiators our temperature starts to drop. We calculated that it is dropping by 0.5C every 20-25 minutes. And with the radiators off the temperature will keep dropping constantly (the lowest we saw so far was about 6C – yes, 6C inside the house with all doors, windows and vents closed)

As you can imagine our bills are very high, and this is with living in a house that is never warm no matter how much we spend on heating.

As it’s a new build house, built last year we never expected anything like this.

We contacted developer who can’t see any issue and told us the house is well insulated.

We continued to look closer at the issue. We invested in Topdon TC005 thermal camera, and what we saw shocked us.

It seems that we have a lot of cold spots in the house which from my understanding might suggest poor insulation, or no insulation at all. All outside walls seems to be very cold (they’re super cold when we touch them as well) but there’s a lot of cold spots in the ceilings as well.

I’m attaching photo of some examples of the cold spots we located in our house.

Does anyone have any experience with poor insulation in new build houses? Can someone advise me if we’re right thinking that the insulation is an issue in our home?

In 2017 we purchased a new detached bungalow, the wall cavities were supposed to be foam filled, we had to have several on the external brick replaced, we noted in places the foam insulation was missing, fitting the TV ariel in the loft we noticed the majority of the insulation was missing, the service valves were missing on most of the appliance, they fitted TRV valves on radiator near the thermostats, the majority of the electric sockets and light fittings had no earth insulation wire, the list was exhaustive.

The previous site manager was not up to the job, fortunately I was a building surveyor and had a good working relationship with the new site manager, I read the builder the riot act, the builder promptly apologised and put everything right.

The problem is that our builder can't see any issue and is avoiding any contact with us.

Unfortunately they will try it on that's builders for you.

QrizB

Panda126 said:

We raised the issue with the developer regarding the radiators being not powerful enough and we've been told that these radiators ' far exceeds the heat loss for the space'.

But I bet they won't share their heat loss calculations with you!

MCS have a pretty good heat loss calculation spreadsheet. It's intended for heat pumps but will work for any heat source. You'll find it linked from here:
https://mcscertified.com/mcs-launch-new-improved-heat-pump-calculator/

If you are able to work throught the spreadsheet you can come up with a reasonable estimate for the heating demand for each room of your home, and see how it compares to the installed heaters.

Panda126

QrizB said:

Panda126 said:

We raised the issue with the developer regarding the radiators being not powerful enough and we've been told that these radiators ' far exceeds the heat loss for the space'.

But I bet they won't share their heat loss calculations with you!

MCS have a pretty good heat loss calculation spreadsheet. It's intended for heat pumps but will work for any heat source. You'll find it linked from here:
https://mcscertified.com/mcs-launch-new-improved-heat-pump-calculator/

If you are able to work throught the spreadsheet you can come up with a reasonable estimate for the heating demand for each room of your home, and see how it compares to the installed heaters.

They actually shared it but it doesn't make any sense. 

QrizB

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.

matt_drummer

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.

MultiFuelBurner

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.