What tolerance do Planning Departments work too?

[iDIY]

Hi Guys,

I have planning consent in place and I will be using a private building control firm.

My architects plans are done to scale on A1 at 50:1 and 100:1.

I'm just wondering how much tolerance the planning department allow for? Converting the scale plans from 100:1 even measuring with a digital vernier gauge the thickness of 2 lines on the plans can be the difference between something measuring 20mm and 21mm. At a ratio of 100:1 that would translate to a wall being 100mm either way?

Do the planning department or the BCO even measure up once the build is under way?

 

[mattylad]

I don't know the answer, but if you put the tolerance on the drawing and it gets approved........

Woody will know.

 

[GeoffJ]

My understanding is that anything within 20cm is accepted for the placement of walls, doors and windows.

This is the length of a house brick (near enough). And is a concession provided to avoid the need for excessive work with part-bricks. Use of part bricks causes wasted time, excessive waste and can result in less than visually acceptable work.
Geoff

 

[^woody^]

There is no tolerance as such. A drawing should have the necessary dimensions on it - and any good designer will have "do not scale" printed on his work.

Some lines on plans if scaled could be more than 50/100mm thick, so no one should be scaling from a drawing for anything other than basic approximate estimates. Certainly not for construction.

The drawings should be accurate, and if not dimensioned, and the planners want to rely on a set dimension, then they should ask for these to be anoted on the plans before approving. They cant rely on a scaled dimension afterwards.

Where there are no dimensions, the existing building would be used as reference. So if a wall is in line with an existing end wall, a party wall or a door or window etc, then that is where is goes and the dimensions are secondary.

Building control wont be bothered with measurements as they will just inspect what is built for compliance. Or if the work goes over to their next fee scale in terms of floor area.

Planners wont ever check what's built unless they get involved with a complaint or enforcement.

 

[Notch7]

The safest way to do things is to specify dimensions so there is no confusion.

The danger these days is that drawings get converted to pdfs and then if they are printed 'fit to page' the scale goes wrong. Its also why drawings now tend to say scale 1:100 when printed at A3 or whatever. A carpenter recently ordered a load of timber from me, he had worked out the length using a scale rule on the drawing, however the drawing had been printed out at A3 and the actual paper size originally was A2.......

I tend to show height dimensions a little bit taller than calculated so that any differences of opinion in ground height are covered. If ground height is variable the safest way is to specify where ground level is taken from.

 

[^woody^]

Planners started to require a reference scale bar on the application plans to help them with scaling at different print sizes when things went electronic a few years ago. Applications will get rejected without one. It helps planners scale, but its still not right - it's more of an elementary check of proportion and and accuracy of the proposed work.

 

[iDIY]

It’s actually a stand alone double garage with storage room above. So basically, as my plans were approved without dimensions, simply stating 100:1 and 50:1 printed at A1, I have a little bit of flexibility if I am a 100mm longer, wider, higher etc.

 

[wessex101]

I have noticed there is quite a trend for submitting planning application drawings without dimensions, just a scale bar.

I saw one recently where they were adding an extra storey on top of a bungalow. They had cleverly drawn it at 1:100 with some very large trees towering above it and none of the adjoining properties shown. It looked OK in isolation. It wasn't until I printed it off and scaled it I realised they were actually raising it by 3 metres and it would be far taller than all the surrounding properties. I suppose they could have stretched that out to 3.2m on site and probably got away with it.

 

[iDIY]

It wasn't until I printed it off and scaled it I realised they were actually raising it by 3 metres and it would be far taller than all the surrounding properties. I suppose they could have stretched that out to 3.2m on site and probably got away with it.

I acknowledge your point but I'm not trying to get away with anything. I simply want to make sure I am not going to have an issue because of the thickness of a line or two on a 100:1 plan.

 

[wessex101]

I acknowledge your point but I'm not trying to get away with anything. I simply want to make sure I am not going to have an issue because of the thickness of a line or two on a 100:1 plan.

I wasn't suggesting that you were, it was just my own musings on one of the many failings in the planning system. It seems odd that they can approve plans without dimensions and thereby have no way to accurately check it gets built in accordance with the approved plans. It is something I intend to exploit at the first opportunity.

 

[iDIY]

There is no tolerance as such. A drawing should have the necessary dimensions on it - and any good designer will have "do not scale" printed on his work.

I have just pulled the Planning Plans and the subsequent Construction Plans again and taken a look. As you said, they do state "Do Not Scale" in with other notes. Elsewhere on the plans it states SCALE (@A1) As Indicated, referring to the fact some parts of the drawings are 100:1, others are 50:1 and others are 20:1.

The Planning Consent was approved based upon the Planning Plans with the above wording and no actual dimensions.

 

[^woody^]

I have just pulled the Planning Plans and the subsequent Construction Plans again and taken a look. As you said, they do state "Do Not Scale" in with other notes. Elsewhere on the plans it states SCALE (@A1) As Indicated, referring to the fact some parts of the drawings are 100:1, others are 50:1 and others are 20:1.

The Planning Consent was approved based upon the Planning Plans with the above wording and no actual dimensions.

Then the association of the garge in context of surrounding features or typical component sizes as shown on the plan will be determining factors.

But TBH, its not that critical for a garage in the garden.

You had an idiot designer if he did not dimension your garage for you. How do you know that you will fit the car or whatever in it? Will it even fit through the door? How will the builders give you accurate quotes?

 

[iDIY]

Then the association of the garge in context of surrounding features or typical component sizes as shown on the plan will be determining factors.

But TBH, its not that critical for a garage in the garden.

You had an idiot designer if he did not dimension your garage for you. How do you know that you will fit the car or whatever in it? Will it even fit through the door? How will the builders give you accurate quotes?

The Brick & Block cavity wall garage is replacing a now demolished prefab concrete double garage so the overall footprint is more or less the same. Obviously the centering of cavity walls on 600mm wide foundations will take a good 500mm off the internal width of the previous garage which was simply built on flags. Likewise the same loss of internal depth will occur but thats fine. No issue with vehicle access as its specifically for motorcycles, a trailer and other tools so the vehicle access door is now sized at 1.8m rather than a cavernous double door. No issue with quotes either as I am self building.

 

[Nakajo]

Well, I wouldn't want my builder working to Planning drawings.

 

[iDIY]

Well, I wouldn't want my builder working to Planning drawings.

Just as well it’s a self build then.