Breeze inside of walls

danindub · 14-04-2014 11:55AM #1

Hi all,

Odd one.

Moved in to a new house recently (build in 2011), got energy rating of A3.

What I noticed however is that there is a breeze inside of external walls as well as ground floor ceiling (it's a 2-story semi-d) - I noticed that while replacing spotlight light bulb and thermostat.

Is this normal?

ct5amr2ig1nfhp · 14-04-2014 12:01PM

Do you have wall vents in each room? Is there ducting going from the external wall to internal wall?

danindub · 14-04-2014 12:03PM

Eduardo Dead Timer wrote: »

Do you have wall vents in each room? Is there ducting going from the external wall to internal wall?

Yes, each room has a vent (plastic pipe).

BryanF · 14-04-2014 01:09PM

new builders, this is why you design for air-tightness:

danindub wrote: »

Hi all,

Odd one.

Moved in to a new house recently (build in 2011), got energy rating of A3.

What I noticed however is that there is a breeze inside of external walls as well as ground floor ceiling (it's a 2-story semi-d) - I noticed that while replacing spotlight light bulb and thermostat.

Is this normal?

normal: unfortunately yes, if designed by a developer to meet min Building regs
under building regulations: if its less than the prescribed amount in part L of 1.5.4 'Air permeability pressure tests' as tested. did you get a test result for air-permeability?

MicktheMan · 14-04-2014 10:15PM

danindub wrote: »

Is this normal?

As BryanF has said, yes this is to be expected when no attention is given to air tightness.

It make a nonsense of the BER rating scheme to think the house got an A3 while heat is being lost by the bucket load through air infiltration.

A lot of house built in the last 10 years have very similar issues.

danindub · 15-04-2014 02:00PM

MicktheMan wrote: »

As BryanF has said, yes this is to be expected when no attention is given to air tightness.

It make a nonsense of the BER rating scheme to think the house got an A3 while heat is being lost by the bucket load through air infiltration.

A lot of house built in the last 10 years have very similar issues.

Is there anything I can do to fix this? Would it cost much?

MicktheMan · 15-04-2014 08:34PM

danindub wrote: »

1.Is there anything I can do to fix this?
2.Would it cost much?

1. Depends on a number of things. Different measures can be taken to reduce the problem and its effects.
2. Difficult to say without testing the house for air tightness to get an idea of the extent of the problem.

danindub · 15-04-2014 10:29PM

MicktheMan wrote: »

1. Depends on a number of things. Different measures can be taken to reduce the problem and its effects.
2. Difficult to say without testing the house for air tightness to get an idea of the extent of the problem.

I am wondering - is this something I should maybe rise with the developer? Is there any rule or specification that they're breaking by making wall insulation essentially useless?

MicktheMan · 15-04-2014 10:42PM

danindub wrote: »

I am wondering - is this something I should maybe rise with the developer? Is there any rule or specification that they're breaking by making wall insulation essentially useless?

Very good question.
I would first ask whether an air tight test was done on the house and what the air tightness result was for the house. Even if no test was done on your particular house doesn't necessarily mean a regulation was broken (a certain proportion of houses are required to be tested in a development)
Depending on when the house got planning/built, there is a pass/fail criteria in the building regulations. If 2008 regs then pass is <10m3/hr/m2; if 2011 regs then pass is < 7m3/hr/m2.
Now, in my experience, a house just passing the 2011 regs with say 6.5 m3/hr/m2 is still a very poor result and will have significant air leakage. Go figure.
It is for this reason that if you search this forum you will find a lot of comment that complying with building regs just isn't good enough for air tightness.

danindub · 16-04-2014 10:32AM

Thanks for your feedback.

I contacted developer and received the air tightness report with a value of Air Permeability of 8.43 m3/hr/m2 envelope at 50Pa and Air Changes 8.86 m3/hr .

I can't understand how the breeze gets to inside of the wall though

MicktheMan · 16-04-2014 10:49AM

[QUOTE=danindub;89958394

I contacted developer and received the air tightness report with a value of Air Permeability of 8.43 m3/hr/m2 envelope at 50Pa and Air Changes 8.86 m3/hr .
[/QUOTE]

:eek:

danindub · 16-04-2014 10:54AM

MicktheMan wrote: »

:eek:

Right... so where can I go from here?

MicktheMan · 16-04-2014 10:59AM

danindub wrote: »

I can't understand how the breeze gets to inside of the wall though

There are several air leakage routes depending on construction type. If your house is part of a development, chances are that your neighbours have the same issues.

To put is simply, no attention was given to air tightness either at design or construction stage.

MicktheMan · 16-04-2014 11:02AM

danindub wrote: »

Right... so where can I go from here?

Have a full heat loss survey done on the house. This should include all heat loss mechanisms and also offer a suite of possible solutions.

pm sent

Breeze inside of walls

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