How close to the Approved Plans do you have to be?

Here's a general interest question:

How close do you have to be to the Approved Plans, when building something?

Basically I have permission to build a rear extension and a front porch.

The approved plans of the rear extension, as close as I can tell, are 6.1 mtr x 6.3 mtr

The approved plans of the porch, as close as I can tell, are 2.0 mtr x 2.3 mtr

When I come to build this do I have to be spot on?

I am going to do the front porch myself, but get bricklayers to do the rear extension.

For example, does my fron porch have to be 2.0 x 2.3 or can it be 2.1 x 2.5 for arguments sake.

I am not trying to build double the size as that would be stupid and would have to get torn down, but I wondered if there were any building tolerances, due to brick sizes etc...

Is any minor leeway allowed in other words?

Thanks,

Bobby

I would strongly advise you not to make any changes outside what would be regarded as normal building tolerance without contacting planning. They will allow you to change many things like this slightly under what’s called a minor amendment but it depends on several factors; if they consider it too great a change, you will have to re-submit & if you change it without permission & get caught, they may make you pull it down

Hi Richard,

What would "normal" building tolerances be for something of the sizes I mentioned above?

Are we talking just millimetres or perhaps a few centimetres?

Any idea?

Cheers.

10-25mm anything more is considered an error rather than a tolerance.. and should be redone..

Gulp. I've rounded to the nearest brick on my extension, for asthetic reasons (i.e. +/- 10cm at either end)

I think I rounded down on one end, and up at the other, come to think of it, so the whole structure has shifted sideways. Schoolboy error- should have measured up properly to brick multiples to start with.

The neighbours are friendly enough though, touch wood.

A fifth of a brick is no more than a thick pencil line.

There is no council in this land that will pull you for something as small as say 45mm.

There are many failed boundary disputes for this very reason.

However, do not push your luck. If you do decide to take the pee and you get a complaint from a neighbour, be prepared for some sleepless nights.