Converting office above retail to residential - how on earth?

antiskeptic

I'm looking at a terraced, period property which has planning permission to convert the upstairs level to an apartment, leaving the ground floor as retail. Mention is made of the conversion conforming to building regs in the permission.

I'm sure there's a whole heap of things to be considered but one thing strikes me as problematic. Surely the fire regs these days require a rating between the ground floor retail and the apartment above. But I don't see how you can add fire rating to the ceiling of the retail (given that's not for sale and is in use), nor work it in from above.

How does this work, anyone know?

Gumbo

antiskeptic wrote: »

I'm looking at a terraced, period property which has planning permission to convert the upstairs level to an apartment, leaving the ground floor as retail. Mention is made of the conversion conforming to building regs in the permission.

I'm sure there's a whole heap of things to be considered but one thing strikes me as problematic. Surely the fire regs these days require a rating between the ground floor retail and the apartment above. But I don't see how you can add fire rating to the ceiling of the retail (given that's not for sale and is in use), nor work it in from above.

How does this work, anyone know?

Very very common and relatively easy to achieve the required fire rating by building from above.

You can lift the floor boards and place a fire resistant layer between the existing floor joists without touching the ceiling below.

Think of how the fire rate floors in protected structures with protected lath and plaster ceilings.

If you google lamitherm or Envirograf Product 53, you will see 2 ways of achieving compliance.

Gumbo

Also, the fire alarm and detection system will need to be interlinked to the retail unit

antiskeptic

kceire wrote: »

Very very common and relatively easy to achieve the required fire rating by building from above.

You can lift the floor boards and place a fire resistant layer between the existing floor joists without touching the ceiling below.

Think of how the fire rate floors in protected structures with protected lath and plaster ceilings.

If you google lamitherm or Envirograf Product 53, you will see 2 ways of achieving compliance.

Sheesh! I would have thought the wooden joists would have to protected in some way or other. Is it simply that time to escape is the intention rather than any desire to stop fire spreading throughout the building? Thanks for the tips, I'm always interested in a bit of reading to add to the knowledge pool (or puddle)

Point taken about the fire alarm

Any other hidden bogies in the likes of this that you know of. I've never dealt with other than straightforward houses

Gumbo

antiskeptic wrote: »

Sheesh! I would have thought the wooden joists would have to protected in some way or other. Is it simply that time to escape is the intention rather than any desire to stop fire spreading throughout the building? Thanks for the tips, I'm always interested in a bit of reading to add to the knowledge pool (or puddle)

Point taken about the fire alarm

Any other hidden bogies in the likes of this that you know of. I've never dealt with other than straightforward houses

The timber joists will char in a fire, but they retain most of their structural capabilities within reason.

Its not the best solution to be honest, as you are simply slowing down the fire spread not stopping it entering the compartment above the retail unit.

In a typical concrete structure, the compartments may stop a fire from completely entering another compartment but not in this case.

Ive had to pull contractors up on leaving construction debris between the joists, not tightly fixing the new fire stopping material between the joists and simply leaving gaps here and there. The quality of the fire stopping depends a lot on the workmanship of the people laying it.

antiskeptic

kceire wrote: »

The timber joists will char in a fire, but they retain most of their structural capabilities within reason.

I suppose they'd last long enough for folk to get out.

Ive had to pull contractors up on leaving construction debris between the joists, not tightly fixing the new fire stopping material between the joists and simply leaving gaps here and there. The quality of the fire stopping depends a lot on the workmanship of the people laying it.

A bit like the insulation installation I've seen o'er the years. Thanks as ever for the insight - seems like it's a not overcomeable issue

Gumbo

antiskeptic wrote: »

I suppose they'd last long enough for folk to get out.



A bit like the insulation installation I've seen o'er the years. Thanks as ever for the insight - seems like it's a not overcomeable issue

If your still in the building by the time the fire has passed through the floor or by the time that the floor collapses, then I think you would have been no longer breathing anyway.

Yeah it's not considered an issue really. It would be the best compartment detail out there but there are tried and tested and certified methods and along with careful installation they work.