I got questions... Dormer.

[ibby]

So the 2.5m dimension is that down the roof slope or a vertical dimension? What is the vertical height from the top of the ceiling joists inside the loft up to the underside of the ridge. If its only 2.5m on the slope then a lofty may be impractical anyway.

When you say 2 dormers joined together then that would surely be just 1 dormer?

This house is detached?

Its an approx measurement
I measured it to my height.
its probably alot higher,

These joists
http://ibrar.co.uk/3d/attic/img_4722.jpg

are at 6ft, so based on that I would say around 1 meter from the bottom of the joist.

Nah lost me there!

Translation is around 3 meters

 

[ibby]

hes replied

"Any increase in width reduces the pitch of the dormer roof,a 3m width will provide a negligible slope,and a poor detail.The width of the dormer does not equate to the width of the room,the very idea of a dormer conversion is the slope of the ceilings.You must also,in my opinion,provide a solution that adds value.A loft conversion provides space but you must always compromise on ceiling height.Your conversion would provide good additional living accomodation with average ceiling heights but we could not marry existing ceiling heights without flat roofed dormers"

 

[ibby]

I want it to look like this

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• ibby
• 10 Feb 2012
• 1

 

[freddiemercurystwin]

ibby, we need the vertical height from the existing floor joists in the loft up to the ridge under the top of the ridge. Cannot work out the volume without that info.

 

[ibby]

ibby, we need the vertical height from the existing floor joists in the loft up to the ridge under the top of the ridge. Cannot work out the volume without that info.

I will climb up tommrow and get the proper measurement from the joists to the top of the ridge

 

[ibby]

ibby, we need the vertical height from the existing floor joists in the loft up to the ridge under the top of the ridge. Cannot work out the volume without that info.

Hi buddy,

Just been in the loft.
From the top of the joist, to the bottom of the ridgebeam , the Height is 3.2 Meters.

Please help with the value calculation. Thanks

 

[jeds]

Your hip to gable will be about 23m³ to 25m³. That leaves, say, 25m³ for the rear dormer. Guessing about 4.2m deep x 3m high the maximum width of your dormer would be about 4m. (4.2x3.0/2x4 = 25.2m³) Which is a lot less than your sketch drawing. Bottom line is you can't build what you want within 50m³. You either need to compromise or submit an application.

 

[ibby]

Your hip to gable will be about 23m³ to 25m³. That leaves, say, 25m³ for the rear dormer. Guessing about 4.2m deep x 3m high the maximum width of your dormer would be about 4m. (4.2x3.0/2x4 = 25.2m³) Which is a lot less than your sketch drawing. Bottom line is you can't build what you want within 50m³. You either need to compromise or submit an application.

Thanks,

for your help,

If I comprimise on the height of the dormer,
The width of it shall we say, 6 Meters and 2.3 meters high 4.2 meters deep.

How much do you think I am over?

 

[ibby]

I know I have not made much sense so far and probably confused myself and other

I am sorry!

So Let me try and start to calculate my roofs current volume.

House size,

7.5 Meters in Lenght
9.8 Meters Width
6 Meters High
3.2 Meters from Joist to Ridge Beam
3.75 Meters Hip

My Current Hip Roof is around half of the lenght of my total house


so,

1st I started to calculate it in a box format and divide it by 3 (as this is a triangle roof/Prism)

7.5*9.8*3.2 = 235.2 m3 / 3 = 78.4 Cubic Meters.

I have now split the 78.4 by 4 and x3 giving me my current cubic meters.
= 58.8

So my Current cubic meters of my roof is 58.8

I have an allowance of 50 Cubic meters

So if I do a Hip to Gable end conversion it would add 19.6 Cubic meters.

30.4 Cubic Meters is left over for the rear dormer conversion.



Now to the dormer calculations...

2.1 Meters High
6 Meters Lenght
4.2 Meters Wide

2.1*6*4.2 = 52.92 Cubic Meters.

If we say, half of the avaliable space was taken from unmodified roof.
If I do, 52.92 /2 it gives me 26.46 Cubic Meters.


26.46 Cubic Meters for the dormers + 19.6 for the Gable conversion puts me at 46.06 Cubic Meters.

[/b]
Now can someone please go over it and tell me if I am wrong!



I am confused

HELP!

 

[ibby]

Untitled

• ibby
• 12 Feb 2012
• 1

Untitled

• ibby
• 12 Feb 2012
• 1

 

[noseall]

I don't know about anyone else but i think some of these loft con dormers look horrific.

Allowing p.d. rights for some of these monstrosities is leaving one hell of an ugly legacy.

I guess these houses will stay in the family as a lot are unsaleable.

 

[ibby]

I don't know about anyone else but i think some of these loft con dormers look horrific.

Allowing p.d. rights for some of these monstrosities is leaving one hell of an ugly legacy.

I guess these houses will stay in the family as a lot are unsaleable.

I will try to make my house look nice from the outside,

Its only a drawing and my dormer will not be flat.

 

[freddiemercurystwin]

I'm not convinced by your dimensions ibby, a photo of your neighbours and your house with a drawn up elevation of your house according to the dimensions you have provided superimposed on top:

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• freddiemercurystwin
• 12 Feb 2012
• 1

Compared to each other it looks like there is a discrepancy somewhere? Could just be the angle of the photo of course but .......

As well as confirming the dimensions are you able to measure the pitch of the main roof and the existing hip too?

 

[ibby]

I'm not convinced by your dimensions ibby, a photo of your neighbours and your house with a drawn up elevation of your house according to the dimensions you have provided superimposed on top:

Untitled

• freddiemercurystwin
• 12 Feb 2012
• 1

Compared to each other it looks like there is a discrepancy somewhere? Could just be the angle of the photo of course but .......

As well as confirming the dimensions are you able to measure the pitch of the main roof and the existing hip too?

Its a photo taken by google car, its at a slight angle.

I know the Hip, sits on a structual wall of the house


What I cant remember is when I took the measurments orginally were they upto the externals eves or the external walls.

The houses are identical in size.

I can remeasure everything and post later on this afternoon.


How do I measure the pitch of the roof?

 

[ibby]

I already have the measurement of the Joist to Ridge beam.

Shall I measure across the house and for a triangle to calculate the roof?