I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

techpro coughed up some electrons that declared:

I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Part L was first introduced in 2002 IIRC, so anything built before this date
may or may not be insulated. I don't know what common practise was in 2001.

Can you see into the cavity anywhere, or feel, say via the attic? Maybe a
mirror on a stick or a webcam and a small torch to have a look.

If anything was installed as the house was built, I would expect solid board
of some sort (rockwool or foam) so it shouldn't settle and should be
visible from above.

Cheers

Tim

techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

I never trust anyone who needs a quick decision.
We paid £179 for cavity wall insulation in our 3 bed detached last year.
Our grant came from our energy supplier who arranged it all. I believe
grants are available from other sources.

On 19 Dec, 12:47, techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Had my Wall Cavities & extra loft lagging done free with Local
Authority grant cos we are oldies. The guy that did the surver
drilled a hole and used an illuminated probe to inspect the cavities
and showed me the result. You should expect the same on your survey.

"Merryterry" wrote in message
...
On 19 Dec, 12:47, techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

-Had my Wall Cavities & extra loft lagging done free with Local
-Authority grant cos we are oldies. The guy that did the surver
-drilled a hole and used an illuminated probe to inspect the cavities
-and showed me the result. You should expect the same on your survey.

You might hope but I wouldn't expect.

translate("It will only cost £169 as you can apply for a grant up to 75%") =
"You pay us £676 (plus VAT) = £777 and you can then see if you can get
something out of the council"


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

In message , Bob Mannix
writes
"Merryterry" wrote in message
...
On 19 Dec, 12:47, techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.


-Had my Wall Cavities & extra loft lagging done free with Local
-Authority grant cos we are oldies. The guy that did the surver
-drilled a hole and used an illuminated probe to inspect the cavities
-and showed me the result. You should expect the same on your survey.

You might hope but I wouldn't expect.

translate("It will only cost £169 as you can apply for a grant up to 75%") =
"You pay us £676 (plus VAT) = £777 and you can then see if you can get
something out of the council"


Not if it works they way ours did.

We had loft insulation done by a company that we got via our Gas
suppliers promotion, we just paid our bit (well we haven't yet, I'm
assuming an invoice will appear in a bit, or when they come back to
finish it next week)), presume they get paid the grant element direct.

Same sort of grants available via local authority schemes.

I'd steer clear of this chap on principle, but getting it done via
application via out supplier was painless
--
Chris French

If they're trying to push you into a quick decision, I'd avoid them.
There are plenty of others to choose from he

http://www.energysavingtrust.org.uk/...ndofferssearch

On 19 Dec, 12:59, Tim S wrote:
techpro coughed up some electrons that declared:



I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Part L was first introduced in 2002 IIRC, so anything built before this date
may or may not be insulated. I don't know what common practise was in 2001.

Can you see into the cavity anywhere, or feel, say via the attic? Maybe a
mirror on a stick or a webcam and a small torch to have a look.

If anything was installed as the house was built, I would expect solid board
of some sort (rockwool or foam) so it shouldn't settle and should be
visible from above.

Cheers

Tim

Thanks. I'll try and have a look.

On 19 Dec, 16:35, mike wrote:
If they're trying to push you into a quick decision, I'd avoid them.
There are plenty of others to choose from he

http://www.energysavingtrust.org.uk/...9/grantsandoff...

Thanks. The interesting thing about that site is that only one of the
offers there expires at the end of this month, and that is from EDF
Energy which is not our supplier. So it seems as if this salesman is
telling a lie about the grant availability to try and push people into
a quick decision.

I'm trying to check our supplier's site www.southern-electric.co.uk to
see if they offer grants but the site does not seem to display in
either Firefox or Konqueror.

On Dec 19, 6:47*am, techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Insulate with what, regular cellulose or chopped up fiberglass settles
alot 10-20%, here in the US a new wet cellulose with glue is used that
wont settle, foam is from R5-R7 and its difficult to get a wall full
and not bow it. Best is an energy audit, Blower door test with
computer read out and Thermal photo. If I were to insulate walls final
payment would be after the Thermal photo showed it was done right, a
blower door test finds leaks yo never knew of and ususaly pays for
itself in a year or two. An overall written audit is best.

techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

Firstly, it doesn't matter when your house was built - they are building
them today without insulation in the walls, it's not 'law', the only 'law'
applies to the U value of the wall and this can be achieved with an empty
cavity, IE thicker thermalite blocks, dry lining and in some cases a wider
cavity with insulation clipped to the back of the inside skin, leaving a
cavity, this cavity can also be insulated afterwards, so just because you
have an empty cavity, doesn't mean it's not insulated.

WRT grant funding, he's taking the ****, the grants are freely available to
all, usually through your energy supplier.
Also, if you are on certain benefits, you can get a 100% grant, likewise if
you are a pensioner recieving certain benefits



I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Drill a small hole through a mortar joint and have a poke around with a
piece of wire, if it's spongy, it's probably already done, if there's a
cavity, it can be insulated

--
Phil L
RSRL Tipster Of The Year 2008

On 19 Dec, 17:59, "Phil L" wrote:
techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

Firstly, it doesn't matter when your house was built - they are building
them today without insulation in the walls, it's not 'law', the only 'law'
applies to the U value of the wall and this can be achieved with an empty
cavity, IE thicker thermalite blocks, dry lining and in some cases a wider
cavity with insulation clipped to the back of the inside skin, leaving a
cavity, this cavity can also be insulated afterwards, so just because you
have an empty cavity, doesn't mean it's not insulated.

WRT grant funding, he's taking the ****, the grants are freely available to
all, usually through your energy supplier.
Also, if you are on certain benefits, you can get a 100% grant, likewise if
you are a pensioner recieving certain benefits



I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Drill a small hole through a mortar joint and have a poke around with a
piece of wire, if it's spongy, it's probably already done, if there's a
cavity, it can be insulated

My wife went through all the stuff the builders handed over when we
bought the house, and there is a folder with a page in it describing
the insulation. For the walls they have ticked "insulating blocks". So
if there isn't any cavity wall insulation I guess we should be sueing
the builders (the 10 year NHBC isn't yet up) rather than paying to
have it installed.

Also if you google "allerdale cavity wall insulation" one of the first
things that comes up is a warning issued by the council about bogus
insulation companies calling on people in the area.

The guy was wearing a tunic with a company name embroidered on it,
showed me an ID (which could be anything) and handed me a leaflet
which includes a company website address, www.nationwideenergyservices.co.uk
which I've been to, but none of that actually proves anything.

In article
,
techpro writes
On 19 Dec, 17:59, "Phil L" wrote:
techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

Rule No 1 of Fight Club:
Never buy anything from a doorstep salesman.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

techpro wrote:

My wife went through all the stuff the builders handed over when we
bought the house, and there is a folder with a page in it describing
the insulation. For the walls they have ticked "insulating blocks". So
if there isn't any cavity wall insulation I guess we should be sueing
the builders (the 10 year NHBC isn't yet up) rather than paying to
have it installed.

Insulating blocks could refer to any number of lightweight concrete
blocks used for the inner leaf - it does not mean the cavity will have
any other filling necessarily.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

techpro wrote:

My wife went through all the stuff the builders handed over when we
bought the house, and there is a folder with a page in it describing
the insulation. For the walls they have ticked "insulating blocks". So
if there isn't any cavity wall insulation I guess we should be sueing
the builders (the 10 year NHBC isn't yet up) rather than paying to
have it installed.


I don't think you have understood my post - there is no obligation for a
builder to install cavity insulation - houses are being built today - now -
without CWI and it's perfectly legal and above board, so long as the walls
meet the U value requirements which they can do without insulation.

Also if you google "allerdale cavity wall insulation" one of the first
things that comes up is a warning issued by the council about bogus
insulation companies calling on people in the area.

The guy was wearing a tunic with a company name embroidered on it,
showed me an ID (which could be anything) and handed me a leaflet
which includes a company website address,
www.nationwideenergyservices.co.uk which I've been to, but none of
that actually proves anything.

It proves that they issue CIGA guarantees, which is the industry standard

--
Phil L
RSRL Tipster Of The Year 2008

techpro wrote in message
news:9a84d6da-c623-4140-8d7a-

I'm trying to check our supplier's site www.southern-electric.co.uk to
see if they offer grants but the site does not seem to display in
either Firefox or Konqueror.

only it seems, "If you are over 70 or receiving benefits"
http://tinyurl.com/439sqp


-

In article ,
says...


Firstly, it doesn't matter when your house was built - they are building
them today without insulation in the walls, it's not 'law', the only 'law'
applies to the U value of the wall and this can be achieved with an empty
cavity, IE thicker thermalite blocks, dry lining and in some cases a wider
cavity with insulation clipped to the back of the inside skin, leaving a
cavity, this cavity can also be insulated afterwards, so just because you
have an empty cavity, doesn't mean it's not insulated.

There was a survey done in Aberdeen, AFAICR, that was designed to show
how inefficient the old stone housing was. Using a thermal camera they
"protographed" the heat leakage. They then went to new wood-framed
houses only to find all the installed sheet installation stopped at the
now-higher-level of the electricity sockets, with nothing below. Some
had complete sections missing...

--
John W
To mail me replace the obvious with co.uk twice

On 19 Dec, 18:56, John Rumm wrote:

Insulating blocks could refer to any number of lightweight concrete
blocks used for the inner leaf - it does not mean the cavity will have
any other filling necessarily.

Thanks. I didn't know that's what that could mean. I thought it
referred to actual insulation within the cavity, such as I have seen
being used in houses being built recently (looks like some kind of
expanded foam with a foil backing.)

On 19 Dec, 19:38, "Phil L" wrote:


I don't think you have understood my post - there is no obligation for a
builder to install cavity insulation - houses are being built today - now -
without CWI and it's perfectly legal and above board, so long as the walls
meet the U value requirements which they can do without insulation.

I did understand the post. I thought the document we unearthed meant
that the builders claimed to have installed it. Now it seems it just
refers to the inner wall of the cavity...

On Fri, 19 Dec 2008 12:59:05 +0000 Tim S wrote :
Part L was first introduced in 2002 IIRC, so anything built before
this date may or may not be insulated. I don't know what common
practise was in 2001.

Part L and its predecessors have been around for ages. The change in
2002 was to reduce the standard U-value for walls from 0.45 (which you
can achieve with brick/unfilled cavity/125mm lightweight block) to 0.35
which generally does need cavity fill. It's quite possible though that
an pre-2002 regs house was built with cavity fill to allow the use of a
cheaper block.

--
Tony Bryer, 'Software to build on' from Greentram
www.superbeam.co.uk www.superbeam.com www.greentram.com

In message , Mark
writes

techpro wrote in message
news:9a84d6da-c623-4140-8d7a-

I'm trying to check our supplier's site www.southern-electric.co.uk to
see if they offer grants but the site does not seem to display in
either Firefox or Konqueror.

only it seems, "If you are over 70 or receiving benefits"
http://tinyurl.com/439sqp

That is for the free insulation.

you seem to have missed the 'Even if you're not eligible for FREE
insulation, we can still offer great discounts on your installation'

for us, having 90 m^2 of loft insulation (topping up the patchy and thin
existing stuff with another 250mm of fibre glass) done via Npower cost
us £296.00 - there was a grant element of 127.00.

This included draft-proofing the loft hatch, insulating pipes, and 3 CW
tanks (we had to pay extra for 2 of those as the grant element only
covers 1, ditto we had to pay extra for 10 m^2 of insulation as the
grant only covers up to 80, but we have a big loft area - that covered
£75 of the cost).

A quick Google up suggests that it would have cost us more in material
to DIY anyway, let alone having to do a horrible job

--
Chris French

techpro wrote:
On 19 Dec, 18:56, John Rumm wrote:

Insulating blocks could refer to any number of lightweight concrete
blocks used for the inner leaf - it does not mean the cavity will have
any other filling necessarily.

Thanks. I didn't know that's what that could mean. I thought it
referred to actual insulation within the cavity, such as I have seen
being used in houses being built recently (looks like some kind of
expanded foam with a foil backing.)

Often they use "cavity wall batts" for that - can be full fill that take
all the cavity and are made from rockwool or similar. Or they can use a
partial fill of a PIR foam like celotex. This is a ridged yellow board
usually covered with foil on both sides.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."


The 2000 regulatins were very exacting insulation wise.

Its a con.


I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Tim S wrote:
techpro coughed up some electrons that declared:

I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

Part L was first introduced in 2002 IIRC, so anything built before this date
may or may not be insulated. I don't know what common practise was in 2001.

Total crap. I built my house to 2000 regs and it is incredibly
insulated. They wouldn't let me do anythng else.

The Natural Philosopher coughed up some electrons that declared:

Tim S wrote:
Part L was first introduced in 2002 IIRC, so anything built before this
date may or may not be insulated. I don't know what common practise was
in 2001.

Total crap. I built my house to 2000 regs and it is incredibly
insulated. They wouldn't let me do anythng else.

Sorry - must have been windows I was thinking of...

Phil L wrote:

I don't think you have understood my post - there is no obligation for a
builder to install cavity insulation - houses are being built today - now -
without CWI and it's perfectly legal and above board, so long as the walls
meet the U value requirements which they can do without insulation.

But it's virtually impossible to reach the U-values required without
some form of additional insulation in a cavity wall construction. Even
with the best aerated concrete block, the best U-value will be about
0.7W/m^2K. This is the upper limit for any _part_ of a wall; the average
must be no more than 0.35W/m^2K, and in reality for a conventional
spec-build volume housebuilder to to achieve a DER anywhere near the
TER, the walls would need to be somewhere around 0.25-0.28W/m^K.

Of course, if you're building a house that will have Kevin McCloud
crawling round it, then you can make use of biomass boilers, sun-spaces,
photovoltaic cells, etc. to reduce you carbon emissions to the point
where it doesn't matter how much heat the walls leak. I just can't see
it being built by Persimmons or Barratts.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed"?

techpro wrote:
I have just answered the door to a guy from a firm called Nationwide
Energy Services Ltd offering to install cavity wall insulation in my
house. He claims that I can apply for a grant of 70% of the cost so it
would cost £169 to insulate our house.

I believe that cavity wall insulation is a good idea. I had it done
back in the '80s in a bungalow I lived in then and it certainly seemed
to help keep the warmth in. If our house really doesn't have cavity
wall insulation I'm happy to have it installed for £169.

However, I'm wondering if this is just a scam, because:
- our house was built in 2001 by Alfred McAlpines (since taken over by
Persimmon Homes.) I thought all houses that recently built had
insulation blocks already inside the cavity walls;
- I'm being pressured to make a quick decision because I'm told "the
grant funding runs out at the end of the year."

I have agreed for them to come and "survey" the house on Monday but if
they told me I needed insulation and I really didn't I wouldn't know
any better.

Could someone who knows about these things please advise?

When you say the house was built in 2001; was this closer to the start
or finish of the estate? With any change in requirements, there is a lag
between when the initial notice was given to the Council, and when the
building was complete, and this can be up to three years from deposit to
starting the work, and then as long as it takes to complete. The rules
on this have tightened up in the last decade, but a big client for the
NHBC can still get around this.

Up until about 1995, it was possible to achieve the U-values without
cavity wall insulation by relying on a mix of double-glazing and aerated
concrete blocks. In 1995, U-values were lowered (better), and I don't
recall seeing any houses or extensions built to these or later
requirements without some form of cavity wall insulation.

Cavity wall insulation is either built-in during construction or
injected after. Built-in types are mineral-fibre batts (Rockwool) which
fully fill the cavity, or partial-fill types such as expanded or
extruded polystyrene (white, pink or blue boards) or polyisocyanurate or
phenolic foam (Kingspan, Celotex, et al - usually dull yellow with foil
on both sides). These leave a residual cavity of between 25mm-50mm.
Injected insulation is either loose mineral fibre (white or yellow),
foam (which sets solid), or polystyrene beads.

You may be able to see evidence of the cavity insulation (or lack of)
around service penetrations (meter cupboards, badly-sealed gas pipes,
etc.), or at the head of the cavity in the loft.

Even if you have partial-fill insulation in the cavity, you shouldn't go
injecting any more. Partial-fill insulation isn't designed to prevent
water tracking across it, and rely on a residual cavity to keep the
inner leaf dry.

However if you do have a clear cavity with aerated blocks, you can still
benefit from cavity insulation. It should lower the U-value from about
0.7W/m^2K to 0.35W/m^2K, reducing the heat loss through the walls by half.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed"?

Tony Bryer wrote:

Part L and its predecessors have been around for ages. The change in
2002 was to reduce the standard U-value for walls from 0.45 (which you
can achieve with brick/unfilled cavity/125mm lightweight block) to 0.35
which generally does need cavity fill. It's quite possible though that
an pre-2002 regs house was built with cavity fill to allow the use of a
cheaper block.

A clear cavity/ aerated block wall only achieves 0.70W/m^2K, according
to my Elmhurst U-value calculator[1]. Which, IIRC, was less than
0.6W/m^2K without thermal bridging that came in in 1995. This was only
acceptable up to then, as I never saw a wall that needed a U-value of
0.45W/m^2K without insulation.

[1] Horrible interface. Bring back SuperHeat!
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed"?

On Sat, 20 Dec 2008 12:47:56 +0000 Hugo Nebula wrote :
A clear cavity/ aerated block wall only achieves 0.70W/m^2K,
according to my Elmhurst U-value calculator[1]. Which, IIRC, was
less than 0.6W/m^2K without thermal bridging that came in in 1995.
This was only acceptable up to then, as I never saw a wall that
needed a U-value of 0.45W/m^2K without insulation.

[1] Horrible interface. Bring back SuperHeat!

Couldn't possibly comment g. Let's just say that no one could
accuse the Elmhurst team of copying anyone else's design ideas. We
had no option but to give up SuperHeat because of the new EPC rules:
I did point out to DCLG the year before that the effect of these
would be to effectively leave the Part L software business in the
hands of a few larger players.

--
Tony Bryer, 'Software to build on' from Greentram
www.superbeam.co.uk www.superbeam.com www.greentram.com