Barn floor - does lowering it cost a lot more?

[Roz]

Hi everyone, 

 

Thanks a lot for having me I value your feedback! The other question I have been wondering (and need to decide on before applying for planning) is about the groundwork. 

 

The structural report says that it's sound and doesn't need underpinning. However, the barn is quite short. I think it's 4m tall, not at the top of the gable - I couldn't get my tape measure up there. 

It used to have a first floor and has the holes where the beams used to go. We'll be wanting to put the first floor back in. I had originally thought I would raise the first floor so there's more head room downstairs, and upstairs will be fine as we'll have it open to the ridge inside. 

 

However, as we'll be hoping to put on an extension, and will need to be doing some insulation and slab laying in the main barn anyway, would it be better to lower the whole floor level? If you're already doing groundwork, how much extra would I expect to pay if I wanted to lower it 30cm or something? 

 

I think I am leaning towards just raising the first floor level. I personally don't mind the walls being a bit lower than the top of my head, as there's so much extra space that will be open from keeping the roof open. But worried I am missing a trick that might not cost much more! 

 

 

[ProDave]

I would dig a test hole carefully by hand to investigate what the walls sit on.

 

I caution this because close to us someone bought a barn to convert, and when they started scraping away at the floor is when they found no foundations under the walls and the excavation needed to lower and insulate the floor undermined what little the walls sat on. They ended up knocking down and rebuilding.

[Cpd]

Out of interest why are you choosing to renovate rather than rebuild ? I totally understand the desire to renovate but after doing a few in my life and seeing many of my friends do it   i am now of the opinion that rebuild should be seriously considered as a first choice for seriously decrepit  structures. 

1 hour ago, ProDave said:

would dig a test hole carefully by hand to investigate what the walls sit on.

 

Good advice.  

[Russell griffiths]

As cpd said, 

not wanting to tell you how to suck eggs, but After you get stuck into that shell you will wonder why you didn’t knock it down and start a fresh. 

Got anymore pics. 

[Roz]

11 hours ago, Cpd said:

Out of interest why are you choosing to renovate rather than rebuild ? I totally understand the desire to renovate but after doing a few in my life and seeing many of my friends do it   i am now of the opinion that rebuild should be seriously considered as a first choice for seriously decrepit  structures. 

Good advice.  

 

11 hours ago, Russell griffiths said:

As cpd said, 

not wanting to tell you how to suck eggs, but After you get stuck into that shell you will wonder why you didn’t knock it down and start a fresh. 

Got anymore pics. 

 

I suppose part of it is that I'm confident we'd get permission to convert it, but not confident we'd get permission to rebuild. It's in a World Heritage Site, but there's precedent for converting barns (similar sized one just across the road).Plus have had good indications from the council. However, on the other hand, others have had a lot of trouble getting permission for affordable home builds. 

 

I know we could apply and change to a conversion if we get rejected, but there is a cost and time factor involved too. 

 

The other reason is that the barn is small, and so is our budget. And whilst it has been said it's cheaper to rebuild, there's size requirements now for minimum sized new builds? Which would push our budget up too (although of course it would be nice to have a bigger house!)

 

Lastly I feel under the impression that 'cheaper to build new' is true if we were to replace with a very simple modern build. But we'd want to add character and interest in some way and feel that would push the budget further. 

 

I suppose I also feel more capable of doing bits and pieces of a conversion ourselves (like repointing) to save money, whereas I'm not sure I would be in a new build.

 

I'm very open to you all refuting these points though, as it will be interesting to know your thoughts! 

Attached some other photos Can also attach my sketch up of what we hope to add in an extension.

 

 

Edited March 7, 2018 by Roz

[Nickfromwales]

Just the integrity of the structure would have me panicking tbh. 

Find out if you could stick build a new, replacment timber framed dwelling if you reclaim and use the available stone to clad the exterior. There would likely be enough there to remanufacture and wrap the current sized building, as well as clad the new extension, so all would look proper and in-keeping. Plus you'd have a comfortable and modern spin with the correct head heights ( subject to ridge height restrictions from the planners ). 

As mentioned, check what lays beneath before even asking another question, but face facts that you'd either have to dig down enough to get 150mm of insulation in and then a thin wooden floating floor, ( to save on depth and cost of a screed ) or apply to raise the ridge height and build over what youve got, eg if the foundations are not sufficient to excavate. 

[Tyke2]

It may be too late to comment on this?

Mine looked similar when I started work.

I lowered the internal floor. The building didn't have foundations and was built on  a slope, so the excavation exposed the underside of the external walls on about 1/3rd of the building. So I had to underpin this area. Underpinning sounds scary, but in reality its just digging holes and filling with concrete - but carefully!

With such a build you will find it is very labour intensive. you end up knocking lots of areas out to rebuild. Costs can escalate easily as until you get the structure sorted and roof/windows complete, it is almost impossible to estimate what is actually needed. you seem to do 3 weeks taking bits down to every 1 week building back up, so it can be demoralising too.

It is pretty much impossible to get a fixed price for any of the work to the structure.

I project managed mine and was the designer, labourer ,estimator, buyer, Qs. I brought in skilled groundworker, masons, bricklayers, carpenter, plumber, electrician.

It would have been easier to demolish and rebuild, but maybe not much cheaper.

Good Luck

[Roz]

18 hours ago, Tyke2 said:

It may be too late to comment on this?

Mine looked similar when I started work.

I lowered the internal floor. The building didn't have foundations and was built on  a slope, so the excavation exposed the underside of the external walls on about 1/3rd of the building. So I had to underpin this area. Underpinning sounds scary, but in reality its just digging holes and filling with concrete - but carefully!

With such a build you will find it is very labour intensive. you end up knocking lots of areas out to rebuild. Costs can escalate easily as until you get the structure sorted and roof/windows complete, it is almost impossible to estimate what is actually needed. you seem to do 3 weeks taking bits down to every 1 week building back up, so it can be demoralising too.

It is pretty much impossible to get a fixed price for any of the work to the structure.

I project managed mine and was the designer, labourer ,estimator, buyer, Qs. I brought in skilled groundworker, masons, bricklayers, carpenter, plumber, electrician.

It would have been easier to demolish and rebuild, but maybe not much cheaper.

Good Luck

Thanks Tyke2. It's not too late - we are still going through planning permission at the moment, with a hopeful decision date at the beginning of next month!

 

We've had a structural engineer look at it and he discovered the floor inside is 30cm higher than the actual base of the walls, so that's good to know. We're going to dig down to at least the bottom of those walls and then insulate etc and see where we're at.

 

We're looking forward to getting started and doing bits of it ourselves, whilst working with same list of skilled tradespeople you mentioned. 

 

How did you insulate yours? Space is at a great premium for us.

[Tyke2]

hi

 

I used an internal skin of thermalite blocks with a 50mm cavity. This was a few years back and was ok from a buildingregs point of view. The house is nice and warm as it has a reasonably high thermal mass and is 100% free of any damp too.

This method is not the best from a space point of view though. But it does give you a solid interior shell to seat your floor joists on.

if you need space you could look at lining the internal walls with a breathable waterproof membrane, fixing insulation to this and batteing out for fixing insulated plasternoard to. You would need to seat your joists on joist hangars fixed to a structural ring beam fixed to teh internal wall. Or I believe thatthere are structural timber/steel lining products avaialble - of which I have not seen in use. Picture is what I started with.

 

 

[Simplysimon]

On 07/03/2018 at 09:48, Roz said:

 

 

 

5 hours ago, Tyke2 said:

 

 

 

not a lot of difference in the structural intergrity of the two buildings either.