Building control for garage door opening modification?

[Andy Hall]

I'm intending to have my double garage door opening modified.

The (double) garage is a brick built single leaf detached building with an apex roof. The end wall of the apex faces the front where there are two single doors. At the front, there are three brick pillars with lintels spanning them to support the walls and forming the door openings.

I want to replace the two single doors with a full width one by removing the centre pillar.

AIUI from a builder, this entails temporarily propping the wall above the existing beams, removing them and replacing with a full width steel beam.

My question is whether building control would apply in this case or if there are criteria for detemining it (i.e. size/height of building etc.).

thx

[Set Square]

Don't know for sure because it's not living space as such - although I would have thought that Building Control would have an interest in anything structural - which could fall down and kill someone if not done right.

Hopefully Hugo will be along with a definitive answer.

[Andy Hall]

All I could find was an area factor of 30sqm and whether or not the building was more or less than 1m from a boundary (however the latter seems to relate to fire issues. However, this would appear to be for building a new building, not modifying an existing one.

OTOH, as you say, there is a potential safety issue.

Hopefully.....

[Hugo Nebula]

On Sat, 10 Sep 2005 15:13:47 +0100, a particular chimpanzee named "Set Square" randomly hit the keyboard and produced:

...Hang on, let me get me shirt on!

If the building is exempt (less than 15m², or less than 30m² if built substantially of non-combustible materials or more than one metre from a boundary), then _any_ work on it is exempt [1].

If it falls outside the above criteria, then Building Regulations will apply, and a B/Regs app will be needed for a structural alteration.

[1] Except the dreaded Part P.

[Andy Hall]

Thanks Hugo.

What is the definition of "built substantially of non-combustible materials"? Construction is brick with tiled roof using timber trusses. Is that considered to be substantially non-combustible enough?

[Hugo Nebula]

On Sun, 11 Sep 2005 17:03:47 +0100, a particular chimpanzee named Andy Hall randomly hit the keyboard and produced:

Yes. Although there's no definition of "substantial", masonry walls and roof covering would count. I've never had a case, but I would guess that a thatched roof would be regarded as combustible.

"Substantially" is another of those words which crop up quite frequently in the Building Regulations, like "reasonable", "appropriate", etc. The old definition of a detached building was something like "built wholly of non combustible materials". This was taken as precluding even timber window frames, which meant virtually any building within 1m of a boundary (including garden sheds) needed an application.

[Andy Hall]

Thanks Hugo.

Notwithstanding this aspect, I am also going to get input from a structural engineer on the requirements for the lintel or beam.

The centre pillar continues up to the apex of the roof, but the remaining infill of the triangular section of front wall is single leaf brick, and of course the roof timbers are supported on the side walls. Not the heaviest of weights, but the span is a bit over 5m.

Are dimensions internal or external for building regulations purposes? I remember reading it was one for planning and the other for building regulation but can never remember which is which.

[Chris Bacon]

It means "built largely or in the main of non-combustible materials".

Brick with a tiled roof is built substantially of non-combustible materials. Timber framed, weatherboarded, tiled, is not. "Substantially non-combustible" is "un harang rouge".

[Hugo Nebula]

On Sun, 11 Sep 2005 21:56:24 +0100, a particular chimpanzee named Andy Hall randomly hit the keyboard and produced:

Building Regulations- internal; Planning- external.

[Andy Hall]

Thank you Hugo. That was the helpful answer.