building regs

[las]

I am having a garage conversion and have been given different advice by different builders! One says that it will be ok having a step down from the house into the new room, open the door from the house and an 8 inch drop to the new room. While the other one says that building regs won't allow any drop at all. Which one is right?

[cmcardle75]

I believe you can normally have a step. 20cm is ideal for this, being around a standard stair riser.

However, this is unlikely to be acceptable for an entirely different reasons. Basically, living space floors must be DPMed and insulated, whilst garages don't. The thickness of the DPM, insulation and screed required to bring an average integral garage floor to house floor standards is about 20cm...

Besides, steps down are horrible. They are prone to causing injuries, particularly with visitors and are really not good for people with reduced mobility or wheelchair bound. You might not be yourself, but you'll probably gain some relatives who are at some point.

If you are intending to move your only ground floor toilet to the new extension then Part M will apply, too, meaning you must provide level wheelchair access.

Christian.

[River Tramp]

Go for the level floor, and lay 1200g or 3 coat Synthapruf, plus insulation and screed.

However, from a BCO point of view,

1. Any rise residential less than 600mm is not a "stair" and not controlled. Once we used to control, and there had to be a minimum of two steps. Therefore single step at door not controlled

1. Most Authorities will require upgrading of insulation/damp protection measures, but not all. My Authority (currently) doesn't, and if you don't want to provide a DPM or insulate the walls, floor & roof, thats up to you. (It's because the work can be regarded as a "material change of use" therefore damp and insulation controlled, or a "material alteration" where it's not)

Strongly advise you try and upgrade damp/insulation as much as reasonably possible, get B Regs permission (submit a Building Notice and get the BCO round to discuss requirements) and ensure Planning Permission is not required, because in a small number of cases it is.

IanC

[Lobster]

I'd agree with Christian - if, as it seems, either of the builders don't realise that in order to fulfil the building regs the floor will need to be deeper anyway, maybe they aren't the best builders to be using?

I believe there's an issue with steps and internal garages in that you can't have a step *down* from the garage into the house because split petrol could flow into the house - I wonder if that's what they're thinking of?

Would recommend the OP simply rings up his local building control office and asks the question direct: he'll get a definitive answer in less time than it took to type out the original query!

David

[Rob Morley]

ITYF there's a requirement for a step *up*, in order to inhibit the spread of petroleum vapour.