Owning a Victorian house I would like to preserve its current style and
replace the old rotten sash and casement windows with new wooden ones.
However money is exceedingly tight, and I enjoy carpentry so I would
like to build my own frames, and obviously fit them myself. Does anyone
have any experience of doing this with relation to building control and
in particular part L? Since the windows would be of my own design as I
understand it I have to calculate my own U values? How is the best way
of setting about doing this, I have seen some sample values and also
note various pieces of software available. How much of a validation
document are building control expecting?

Any experiences shared/advice much appreciated. Thanks.

Cod Roe wrote:
Owning a Victorian house I would like to preserve its current style
and replace the old rotten sash and casement windows with new wooden
ones. However money is exceedingly tight, and I enjoy carpentry so I
would like to build my own frames, and obviously fit them myself. Does
anyone have any experience of doing this with relation to
building control and in particular part L? Since the windows would
be of my own design as I understand it I have to calculate my own U
values? How is the best way of setting about doing this, I have seen
some sample values and also note various pieces of software
available. How much of a validation document are building control
expecting?
Any experiences shared/advice much appreciated. Thanks.

It's the glass that has the u-value, and I don't think you'll be making the
units yourself!
when you order the DG units, they will have k-glass or equivalent on the
inside pane....you can get building control to pass them off for a set fee
per house, or it may be per visit, so you might want to make them all and
get him out once.
If any of your window cills are below 1 metre from the floor, you'll also
need toughened glass.

On Dec 11, 8:59 pm, Cod Roe wrote:
Owning a Victorian house I would like to preserve its current style and
replace the old rotten sash and casement windows with new wooden ones.
Any experiences shared/advice much appreciated. Thanks.

I think you should look carefully at the regs. ISTR that you may repair
windows without having building regs and planning permission etc. I
think common sense would say that your newly repaired windows would be
more efficient than the current ones. It think it would be very
difficult to define exactly what 'repaired' means. I would suggest it
is quite likely that many 'original' windows might have had a few new
frames in their life as well as some new panes...a bit like Trigger's
broom from Only Fools and Horses.

"Phil L" wrote in message
.uk...

If any of your window cills are below 1 metre from the floor, you'll also
need toughened glass.


IIRC that should be 800 mm.
I don't recall when it changed.

Read Part L he
http://www.planningportal.gov.uk/eng...314231799.html

It explains the 2 acceptable methods of calculating u values.

I made and fitted a complete set of windows for a chapel conversion,
specifying 4/16/4 sealed units with a u value of 2.0 and proving they
would meet the ventialtion requirements (based on opener to floor area
ratio) as part of a "full plans" application.

You probably only need to make a short statement on a building notice
to your local BCO.

Alternatiely, if it's like for like, replace (most of) each window as
you make it and it may well be considered repair - which requires no
interaction with planning or building control.

wrote in message
ups.com...


On Dec 11, 8:59 pm, Cod Roe wrote:
Owning a Victorian house I would like to preserve its current style and
replace the old rotten sash and casement windows with new wooden ones.
Any experiences shared/advice much appreciated. Thanks.

I think you should look carefully at the regs. ISTR that you may repair
windows without having building regs and planning permission etc. I
think common sense would say that your newly repaired windows would be
more efficient than the current ones. It think it would be very
difficult to define exactly what 'repaired' means. I would suggest it
is quite likely that many 'original' windows might have had a few new
frames in their life as well as some new panes...a bit like Trigger's
broom from Only Fools and Horses.

Over the past three or more years I've built & fitted 12 sash windows in our
1870 house to replace a motley collection of plastic things.
I regard it as repairing with attitude rather than replacing.
Also we're in a conservation area which trumps part L.

Phil L wrote:
Cod Roe wrote:
Owning a Victorian house I would like to preserve its current style
and replace the old rotten sash and casement windows with new wooden
ones. However money is exceedingly tight, and I enjoy carpentry so I
would like to build my own frames, and obviously fit them myself. Does
anyone have any experience of doing this with relation to
building control and in particular part L? Since the windows would
be of my own design as I understand it I have to calculate my own U
values? How is the best way of setting about doing this, I have seen
some sample values and also note various pieces of software
available. How much of a validation document are building control
expecting?
Any experiences shared/advice much appreciated. Thanks.

It's the glass that has the u-value, and I don't think you'll be making the
units yourself!

The U value is a composite of the whole window and the frame.

For steel windows, for example, even double glazed panels can be worse
than single glazed windows in wooden frames, as the frame conducts so
much heat.

However, though timber isn't a great insulator, it's not a bad one.

U values for windows should be 1.8 or below.

http://www.fenland.gov.uk/theme/fdc-...sset_id=319475

Looking on page 15, for example.
It gives the u-value of triple glazing with no thermal break metal
frames as 2.1, with no thermal gap, and 1.4 with, so it's reasonable to
assume that the difference of 0.7W/m^2 is between the metal and wood
frames.

If we assume that the frames are 4m long, and this is a 1m^2 pane, then
with 50mm square timber, this is .2m^2 of timber.
Timber has a k value of around 0.14, or for 1/20th of a meter thickness,
that's a U value of 2.8.

Divide by 5, as it's only the contribution of the window frame that
you're interested in, and it's probably around 0.6 of the 1.8 U value
for double glazed wooden framed windows that comes from the wood.

(needed to do this sum anyway - as I'm considering making my own
windows).

Ian Stirling wrote:
Phil L wrote:
It's the glass that has the u-value, and I don't think you'll be making the
units yourself!

The U value is a composite of the whole window and the frame.

That was my initial understanding, but if you look at Table 2 on Page 20
of the Regs it says U-value=2.0 or centre pane U-value=1.2. So from
this it would seem as longer as your double glazed units manage 1.2 then
you are ok, or am I miss understanding something?

On Dec 11, 8:59 pm, Cod Roe wrote:
Owning a Victorian house I would like to preserve its current style and
replace the old rotten sash and casement windows with new wooden ones.
However money is exceedingly tight, and I enjoy carpentry so I would
like to build my own frames, and obviously fit them myself. Does anyone
have any experience of doing this with relation to building control and
in particular part L? Since the windows would be of my own design as I
understand it I have to calculate my own U values? How is the best way
of setting about doing this, I have seen some sample values and also
note various pieces of software available. How much of a validation
document are building control expecting?

Any experiences shared/advice much appreciated. Thanks.

"Repair" the frames this year re-using the old sliding/opening bits and
then "repair" those next year.

MBQ

Cod Roe wrote:
Ian Stirling wrote:
Phil L wrote:
It's the glass that has the u-value, and I don't think you'll be
making the units yourself!

The U value is a composite of the whole window and the frame.

That was my initial understanding, but if you look at Table 2 on Page
20 of the Regs it says U-value=2.0 or centre pane U-value=1.2. So
from this it would seem as longer as your double glazed units manage
1.2 then you are ok, or am I miss understanding something?

The building inspector who looks at your new windows isn't interested and
neither should you be.
The glass will be K-glass and it will be checked, likewise if it's toughened
or not...they don't have a thermometer to check inside and outside temps of
framje material - wood is better than PVC, PVC is better than metal, that's
all he knows and that's all he needs to know.

The message
from "Phil L" contains these words:

The glass will be K-glass and it will be checked,

Out of interest, how do they check?

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from "Phil L" contains these words:

The glass will be K-glass and it will be checked,

Out of interest, how do they check?

AIUI, point an IR thermometer at it, and it's very different between
glass and not.

On 2006-12-12 19:51:21 +0000, Guy King said:

The message
from "Phil L" contains these words:

The glass will be K-glass and it will be checked,

Out of interest, how do they check?

Look for the Pilkington logo?

Guy King wrote:
The message
from "Phil L" contains these words:

The glass will be K-glass and it will be checked,

Out of interest, how do they check?

It's written on the inside of the unit!

(sometimes)

Every one I've done, he's asked me to leave the stickers on until he's seen
it...these usually have unit measurements, date, type of glass, customer
name, house number and manufacterer printed on them, hard to forge, although
I wouldn't be surprised if someone hadn't tried...

The message
from Andy Hall contains these words:

Out of interest, how do they check?

Look for the Pilkington logo?

It's on a sticker - which of course you remove 'cos it's in the middle
of the glass when they're delivered.

--
Skipweasel
Pay no attention to that man behind the curtain.

Phil L wrote:
Cod Roe wrote:
Ian Stirling wrote:
Phil L wrote:
It's the glass that has the u-value, and I don't think you'll be
making the units yourself!
The U value is a composite of the whole window and the frame.
That was my initial understanding, but if you look at Table 2 on Page
20 of the Regs it says U-value=2.0 or centre pane U-value=1.2. So
from this it would seem as longer as your double glazed units manage
1.2 then you are ok, or am I miss understanding something?

The building inspector who looks at your new windows isn't interested and
neither should you be.
The glass will be K-glass and it will be checked, likewise if it's toughened
or not...they don't have a thermometer to check inside and outside temps of
framje material - wood is better than PVC, PVC is better than metal, that's
all he knows and that's all he needs to know.


Wood falls within a predictable range as does plastic and metal..there
are tables for calculating U values...if the BCO is unhappy he will
require YOU to spend YOUR money on a report by a heating consultant who
will do the calcs and present a report.