[Closed] Extension built - impact on buildings insurance?

Have you not spoken to them already? Ours were pretty fussy about requirements during building work, largely around security. Best to just ask them about value, I doubt you'll need any surveys.

We went through the same last year, pretty huge extension. Our premium only went up by a small amount, I self declared rebuild costs. I also pointed out improved security, better doors, new windows, wired smoke detectors etc. Premium hardly changed.

Ours were pretty fussy about requirements during building work, largely around security

We moved out during our building work and cost of insurance to cover an empty house was insane so we didn't insure it. Not a comfortable position at all.

The policy covers up to £1m which will still easily be sufficient,

Same as ours, I can't imagine they won't be able to rebuild it for considerably less than that, so I've never bothered looking into it anymore.

Sounds like your extension is significantly bigger than ours. When ours was complete we just asked a local friendly estate agent if he'd mind valuing it for us, made it clear it was just for insurance purposes. He advised on rebuild cost etc, premium didn't go up by much at all IIRC

Thanks all. In truth, most of the extension has happened "outside" with a box being built on the side and only recently been knocked through, by which point the extension was (as someone has suggested) more secure that the rest of the existing property with windows etc. Will monitor the thread but I'm getting a decent picture, thanks!

Remember the business sum insured may be the full rebuild, including site clearance snd alternative accommodation for the 12 months it may take, but should still be ok

The policy covers up to £1m which will still easily be sufficient, funnily enough, given we’re not in That London,

The policy will cover £1m rebuild cost, including site clearance, architects, fees, planning, and rebuild costs as new. £1m is a hell of a lot for most normal houses, so unless you have 6 bedrooms+ pool+ detached double garage with staff rooms I wouldn't worry about it. It's nothing to do with value. So nothing to do with London really (although rebuild prices are generally higher darn sarf).

but how do I go about revising the rebuild value of the property?

You shouldn't need to for insurance purposes, unless the insurer asks you to provide an updated estimate or if you think it's over £1m

Or do I need a survey?

See above. However, a subtle point missed by many about insurance is that it's your responsibility to prove the amount of your loss. So, if you have a recent survey it burns down, you do have a strong case to get back exactly what was lost. Insurers can try to pay the "average" amount for your postcode, so if the whole thing burned down and (say) you have paid for super mega whizzy taps, but live in an iffy postcode, the insurers will try and fit bog standard taps unless you can prove otherwise.

Clearly I will speak to the insurers IDC, but over the last c.20 years I’ve tended to ask here first, so why break the habit of a (half a) lifetime??

I don't think you necessarily need to, but I'd always say better safe than sorry. So yes, make the call.

Other points are that alternative accommodation costs are not usually part of a rebuild cost.

Also while your extension was being built as an external box, it would have been covered by the builder under something called Contractors All Risks. When they knocked through, it becomes part of your home and your buildings cover generally kicks in.

There is a simple rebuild calculator here.
https://calculator.bcis.co.uk/

See above. However, a subtle point missed by many about insurance is that it’s your responsibility to prove the amount of your loss. So, if you have a recent survey it burns down, you do have a strong case to get back exactly what was lost. Insurers can try to pay the “average” amount for your postcode, so if the whole thing burned down and (say) you have paid for super mega whizzy taps, but live in an iffy postcode, the insurers will try and fit bog standard taps unless you can prove otherwise.

Who would we be suggesting did the valuation out of interest? An estate agent or a surveyor?

PS - no whizzy taps here 😉

There's no single answer to that - it depends on what you think you need, how much money you have and how normal your house is.

An estate agent might do it, a surveyor, you could do it yourself with a bit of groundwork on RICS and you keep your receipts from the work you've had done. When you moved in, your mortgage offer probably had a rebuild figure on it so you can often extrapolate from there.

If you are sitting on £1m rebuild then you're probably on the wrong type of insurance policy anyway. 😁

Oh gawd no, nowhere near £1m, as previously stated. Thanks for all of the above everyone, very useful.

😂 I just used the RICS thing to check our rebuild out. Like you we're on a blanket £1m policy. When we moved in here I'm pretty sure it was 176k rebuild (2010). Now? 316k 😲 I am going to remeasure it tomorrow rather than guess the floor area, but I know I'm not far out.

Also, extensions cost proportionally more as they're careful to not disturb existing rooms etc, if your house is gutted by a fire, then the rebuild won't be worrying about not getting dust in the living room whilst working on the kitchen, they'll just knock most of it down and start again - which is much quicker and cheaper.

Most residential home policies rate on bedroom/bathroom count. If your re-build is below the declared sum of £1m and your number of bedrooms/bathrooms hasn't changed it's likely to have little to no effect. If you've added bedrooms/bathrooms expect your premium to rise.

Still update the insurer, some wish to know about extensions in past 25 years.

You can to be safe arrange a desktop valuation, we use these guys - https://www.rebuildcostassessment.com/ , will be about £130 or as referenced above, use the free RICS tool, https://www.rics.org/uk/products/data-products/insurance/

We had to inform our insurers during the build, it may even have been part of the planning or building warrant, (I may be wrong on this however), they wanted informing of when it was watertight and then completed build. From what i remember there was an uplift in costs of about £20 during the build as the risk was higher. It didn't change our yearly costs as the kitchen was extended and a bedroom extended, so the number of rooms didnt change.