Underpin existing conservatory, or replace?

Phil4432

Hello all,
So my existing conservatory, which was built on non existent foundations, is falling apart.  Just over a decade old.  A couple of builders have made the suggestion that in order to save money, I could simply underpin the existing dwarf walls and have new windows, doors. 

This sound credible, but I'm thinking of value to the house.  As soon as you mention underpinning, buyers tend to run and insurance companies have a thousand questions.  Its not to the main building, and the conservatory is a temporary out building.  You could just say that you repaired the conservatory and gave it foundations, but the term 'underpinning,' may be inevitable, when describing the property to a potential buyer.

Perhaps I'm worrying about nothing, but its important to consider all angles.  If anyone has any thoughts on this, that would be much appreciated.

vw100

As you say any sign of underpinning you may have future buyers running a mile, or the surveyor picking it up and then wanting further surveys to satisfy the lender. It opens a can of worms. Weigh up the cost for the two options, if for slightly more outlay it may be prudent to get the whole done new properly once and for all. 

FreeBear

If you are underpinning, you basically dig a trench, excavate under the existing foundations, and then shove a load of concrete in. Digging totally new foundations and rebuilding the dwarf walls isn't really that much more work. If there is some way to jack up and support the conservatory, you may not need to dismantle it - Although, if you have doors & windows to replace, you are already half way to dismantling.

If a job is worth doing, do it properly rather than trying to save money where there isn't really any savings to be had.

Phil4432

vw100 said:

As you say any sign of underpinning you may have future buyers running a mile, or the surveyor picking it up and then wanting further surveys to satisfy the lender. It opens a can of worms. Weigh up the cost for the two options, if for slightly more outlay it may be prudent to get the whole done new properly once and for all. 

True.  Whereas a new conservatory just gets noted as a new conservatory, as soon as you mention 'underpinning,' even if it is to a temporary out building, the alarm bells start ringing. 

Phil4432

FreeBear said:

If you are underpinning, you basically dig a trench, excavate under the existing foundations, and then shove a load of concrete in. Digging totally new foundations and rebuilding the dwarf walls isn't really that much more work. If there is some way to jack up and support the conservatory, you may not need to dismantle it - Although, if you have doors & windows to replace, you are already half way to dismantling.

If a job is worth doing, do it properly rather than trying to save money where there isn't really any savings to be had.

Also the chance of the builder throwing up his hands and saying, 'It's the original builders fault, not my fault,' if there were to be any issues. 

The advantage of jacking up the existing 300MM(!)  foundations is that some costs would be cut, the original doors and windows have absolutely no issues, but are over 10 years old at this point and not under guarantee.  Could be good for another decade, might leak next week. 

Phil4432

Mickey666 said:

Underpinning is not very difficult, just a lot of digging.  I’d DIY it and then forget all about it, including when selling.  Nobody lists all the DIY work they do on their house when it is up for sale so why should underpinning - or whatever you want to call it - be any different.  That’s why buyers pay for surveys.  Besides, if the job is done properly then the conservatory walls WILL have foundations.

I'd just say the foundations were extended, but if directly asked if they were underpinned I'd have to disclose the truth that the builder did indeed use the terms underpinned. Alarm bells for the vendor.  Even though the main building is absolutely fine, the dreaded U word has been used.

Well, looks like a new conservatory.   

-taff

Conservatories in general don't need planning permission or foundations or anything sensible like that. Why would you mention the work you may or may not have done when it's not necessary? If you want it fixed, fix it. You're not underpinning the house.

Phil4432

-taff said:

Conservatories in general don't need planning permission or foundations or anything sensible like that. Why would you mention the work you may or may not have done when it's not necessary? If you want it fixed, fix it. You're not underpinning the house.

Yes, that's also a point to take on. I'd say that there should be some sort of foundations plus good rainwater drainage though, so you can get 10-15 years out of it hassle free.