Loft conversions queries

Afternoon all!

We're looking in to getting our loft converted. We want to have a dormer with a couple of roof lights. Stick an en suite in and it'll basically be our master bedroom. The house is a 3 bed 1930's terrace in London.

I've made a request for a Lawful Development Certificate to save any potential grief when selling the house down the line though I understand this to be well within the scope of a PD.

Where i'm a bit more confused is with building regs - and what ultimately I need to supply to the LDC. The builder we're probably going to use for the work is one who has recently completed the same at a neighbouring property. Our house is a mirror image though there are some differences in that theirs being end of terrace doesn't seem to have a chimney stack any more (presumably removed).

Anyway, I understand that this work can be completed under a building notice. My questions are:

• Will LBC want to see drawings?
• Will they need/want calculations (basically are we going to need to get a structural engineer to do some calcs)?

If I need to get an architect and structural engineer on board then so be it. Just hoping, as always, I can save a few quid. Certainly when we did a rear extension last year we needed drawings and a structural engineer though this was done under a full plans notice as we were building over a sewer, sticking in a couple of large RSJs and digging footings for the building. I feel that a loft conversion may be a lot more straight forward. Maybe it is but we still need drawings etc...

My next question (more building related) is can we remove the chimney breast in the loft to give us a better shaped room? We share the outside part of the stack with the neighbours on the other side so presumably the stack would need to stay? I'm hoping this way that in time when we do our living room in a few years we can remove the fireplace tottaly and open the room out to create a better space.

TIA

Yes you can do it on a notice if you want to bear the risk. Calculations will be at the inspectors discretion. But you need to be sure what you will build is correct before you build it.

You most likely can't support a stack above the roof, with supports just below the roof. You'll need to keep part of the breast.

^woody^ said:

Yes you can do it on a notice if you want to bear the risk. Calculations will be at the inspectors discretion.

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Thanks for your reply Woody. Is the preferred method to do it on a Full Plan submission then? I think it costs around the same as a building notice in my borough anyway so happy to do it under full plans if required - obviously this will then require drawings then. When you say calculation will be at the inspectors discretion - what specific calculations would they be looking for? I know with the extension it was for the RSJs but what in particular in relation to a loft conversion?

^woody^ said:

You most likely can't support a stack above the roof, with supports just below the roof. You'll need to keep part of the breast.

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Hmmm. I feared as much. Might be best leaving it in then. Though I suppose this is where a structural engineer would be useful - to suggest potential ways around this issue.

they will most likely want calcs for all steel work, floor joists and roof structure.
as to whether to go full plans , depends upon the confidence you have in your builder. full plans will make it easier to get like for like quotes.
Though last year I did my 5th loft conversion in the same street, the first two had full plans the last 3 had no drawings whatsoever and were done on a building notice, with a written spec essentially forming the contract.

chappers said:

they will most likely want calcs for all steel work, floor joists and roof structure.
as to whether to go full plans , depends upon the confidence you have in your builder. full plans will make it easier to get like for like quotes.

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Thanks for the reply. Having actually got up there now and started looking at the work that needs doing I can see calcs are going to be needed. So drawings will be as well.

My LABC seem to charge the same for full plans and a building notice. Does this sound right?

If this is the case then surely I'm better off going for a full plans submission as I'm getting drawings and calcs done anyway - yes it'll take longer but it'll mean I'm better covered regarding building regs as the LABC will have checked everything anyway?

Interesting that you did the later conversions on a building notice after previously doing full plans Chappers. Were you using the same contractor throughout? I'm guessing by your third you knew what needed doing - especially in the same street with presumably similar houses!

bongos said:

My LABC seem to charge the same for full plans and a building notice. Does this sound right?

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Yes this is right, sometimes it's more in fact because Mr BCO needs to allow for the hand-holding and messing about that's entailed in doing it on a Notice, when it's done on a full plans the spec's are all approved so really he's doing a box ticking exercise when he does his inspections with full plans. Personally I think you gotta be nuts to do a lofty on a Notice. How do you know your builder is giving you a market price if you can't compare his price accurately to someone else's - which is impossible without a decent of drawings/specs?

bongos said:

Interesting that you did the later conversions on a building notice after previously doing full plans Chappers. Were you using the same contractor throughout? I'm guessing by your third you knew what needed doing - especially in the same street with presumably similar houses!

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I was the contractor, they were all for separate clients, the first two had already done their own full plans submission and the other three came as a recommendations from the others.

Cheers for the info guys. Is a full plans submission something I can do myself or something I'm best to leave to an architect?

It depends if you can draw plans, specify materials and standards, and design.

^woody^ said:

It depends if you can draw plans, specify materials and standards, and design.

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Well I'm sure I could specify materials, standards and design with some work. But no, I can't draw plans...

I'd assumed the drawings that have been done would be used for the building regs as well but do they need to be different?

Maybe it's just less grief to get the architect to do it anyway.

To those with experience, does a quote of £600 sound reasonable for a structural engineer to complete calculations for a loft conversion? (London prices) It doesn't sound too unreasonable but would be interested to hear what people think/experience.

Yes- in London that's what a plumber charges just for showing up - but you're welcome to obtain an alternative quote

Thanks. This was the friend of the architect so wanted to check.

£600 is OK.