Rear Extension - Underfloor insulation for EXISTING suspended floor?

[fivefive]

Hey guys,

Just wondering if anyone know, When you do Rear extension (concrete), if you leave the existing suspended floor wooden floor as it is, would that be fine please?

Because my building control inspector just asked us if we have insulated the existing suspended floor??? Is this a Building Regs which we must do or entirely optional? Or does he only need to inspect IF WE HAVE put in the insulation?

This is with regards to "Underfloor insulation being laid between the floor joists ". I have checked my structural plans, there is no mention of anything that need doing to existing suspended floor. Our plans have done and passed the full plans check.

Obviously, I don't want it if it is not required by Building Regulations, as we have a very limited budget.

Many thanks,
fivefive

 

[freddiemercurystwin]

You shouldn't need to touch the existing floor, however he could be querying how you expect to ventilate the existing floor after you've built your extension and blocked up the underfloor vents.

 

[John D v2.0]

I think if the floor is in the same room (open plan) it would certainly be good practice to avoid cold spots. In ours we're matching the construction of the new floor to the old and insulating the lot too the same standard.
As to requirements it kind of depends on your definition of a room. And even if it's a separate room, whether you've replaced the floor boards would make a difference.

 

[fivefive]

You shouldn't need to touch the existing floor, however he could be querying how you expect to ventilate the existing floor after you've built your extension and blocked up the underfloor vents.

Thanks! Yes, he already gone through the "ventilate the existing floor" topic with us... and we added the air vents in which all passed.

 

[fivefive]

I think if the floor is in the same room (open plan) it would certainly be good practice to avoid cold spots. In ours we're matching the construction of the new floor to the old and insulating the lot too the same standard.
As to requirements it kind of depends on your definition of a room. And even if it's a separate room, whether you've replaced the floor boards would make a difference.

We haven't replaced the floor boards of the existing floor, so we didn't even know we need to lift them up and insulate it. It's simply out of our budget. It's very surprising that the Building Control inspector even asks us about it...

So the only thing I can think of is, he suspects that we have done it and so he has to inspect it if we have

 

[freddiemercurystwin]

Why don't you ask him?

 

[fivefive]

Why don't you ask him?

I would like to, but I don't really trust his answer because he is a very fussy person. Whenever I ask him something, he would never give me a definite answer, which makes the situation very stressful and difficult for me...

I would love to talk and just ask him, but I want to figure out what's right and what's not before I start the conversation with him, I don't want it to be a one-way conversation where he just tell me what he wants and I don't have a clue if I actually have a choice to refuse his request at all.

To me, I don't want to do it unless it's an absolute Building Regs requirement. Reason being is because I don't have any extra money left to pay my builder to do additional work like this. Also, this BC inspector, he can easily come up with things he doesn't like, and he just say i should do X, Y and Z.

X, Y and Z would always cost me much more £££...