Rebuilding outer leaf

[Jilly]

I’m guessing external insulation wouldn’t work?

[BotusBuild]

11 minutes ago, Jilly said:

I’m guessing external insulation wouldn’t work?

I can't see why not. I think it's been suggested already. 

[Gus Potter]

3 hours ago, Iceverge said:

I'll reiterate my point buried in my earlier post. 

 

The worse thing that any self builder can do is value their time at zero. 

 

You need to put a £ figure on every hour you spend on site. Say £20. 

 

 

Re taking down the leaf of a cavity wall. @Gus Potter and @saveasteading might be along to discuss why this is a bad idea. 

 

As far as I understand the two leafs when ties together act more like a wide solid wall, like a "H" rugby goals. 

 

When you take away half almost all of the lateral strength disappears.

Good advice.

 

In a standard cavity wall (say 50-75mm cavity) the two leaves act together. When doing calculations we derive an effective thickness of the wall. A bit like this bit from the the BS code. But the strength of the wall as @Iceverge say rapidly decreases exponentially the thinner the effective thickness.

 

There are other kinds of masonry walls. Solid walls are say built with English Garden bond. These you can't really take down the inner skin in any practical way. There is  a wall called a collar jointed wall. Here the cavity is no more than 25mm and fully filled with mortar. One key thing here (collar wall) is that the wall ties are much thicker and more robust. Ancon do a wall tie for collar jointed walls. A collar wall tied with the right ties acts like a solid wall so you get more bang for your buck.

 

 

It's a good idea to value you time. £20.00 per hour seems reasonable. That's £160 a day. A trade rate up near Glasgow can vary from say £100-120 a day for an inexperienced labourer up to say 220 - 250 a day for a good experienced joiner( chippie)... more for a spark and techy folk. Now if that is all through the books and you are doing an extension there may be vat and an extra contractor profit / overheads to go on top of that.

 

When you look at it this way it can be good or bad! If your time spent on site is doing some work then you win a watch. You efforts are tax free and not subject to contractor profit for example. Any time spent keeping an eye on the builder is still worth while as it can head off disputes and extra claims for cost later on. It can help keep the quality of workmanship up too.

 

 

 

 

 

 

 

 

 

 

[Mike]

7 hours ago, allthatpebbledash said:

Hardly makes sense to knock it down to save further 5% on the tax considering cost of JCB and new foundations. My only issue is the pebbledash, maybe I should just own it? Paint it white, dash showing and all?

It's not just the VAT. I've undertaken several deep renovations myself, as well as having managed & priced them commercially, and they always turns out to be more expensive than rebuilding would have been - unless you're doing much of the work & discounting the cost of your labour.

 

In addition to strip-out costs, many things just take more time and/or cost more. For example, building a doorway into a new internal wall is more-or-less 'free' - the extra costs are roughly balanced out by saving 1.5m² of blockwork. On the other hand, knocking a hole through an existing wall, well that's a couple of days work + additional materials. Then there are things you find that you didn't expect that need fixing - walls, floors & ceilings out of level; botched DIY; sagging rafters; dry-rot; lead water mains; cracked sewers, whatever - which also takes more time to fix than fitting from new. And making an old house properly airtight - which is highly recommended - is almost always more complex because it wasn't considered as part of the original design.

 

There are good reasons for not demolishing. Maybe you just want to tart it up & flip it. Maybe you need to live in it because you have nowhere else and a caravan is out. Maybe the building has a particular heritage value (whether listed or not). Or, as with my current project, maybe it's an apartment - which kind of rules out demolition!

 

But if you do decide to renovate then do make sure that includes a thermal upgrade to at least Building Regs standards. Better than that if you're concerned about future energy costs and / the future additional value that it's likely to provide.

[Iceverge]

I cannot emphasis this enough. There'll always be more work to do than one person can manage and you need a metric to value your time. £ or € or $ is a pretty good one. 

 

Let me give you some examples. 

 

I stupidly chased our walls with a 9" grinder ( because I had it) rather than pay €120 for a days rental of the proper tools. 

 

It took me about 20 hrs of pure torture. 

 

My mate rented the machine and did his house in an afternoon. At €20/hr it stupidly cost me double what his did. 

 

I can lay blocks, but I'm slow and I don't like doing it for more than a couple of hours as I'm too soft. I reckon about 10/hr would be average. That come to about €2/block. Maybe that makes some sense for small projects but no way for a large house. 

 

Gains can be made where you do the donkey work of someone who's more highly skilled. Like UFH pipe laying or pulling cables for wiring. Plumbers and sparkles are expensive laborers. 

 

Another example, my mate, extended a cottage. 4 men took 2 days to crowbar and sledge down an old stone chimney. All unpaid, family, mates etc. then they took the same again to break out the old floor. Then the same to take off the roof. 

 

Had they hired a digger and demoed the house their mate time could probably have saved them multiples of the cost later in the build. 

 

 

 

 

 

 

 

 

 

 

[Iceverge]

4 minutes ago, Iceverge said:

I cannot emphasis this enough. There'll always be more work to do than one person can manage and you need a metric to value your time. £ or € or $ is a pretty good one. 

 

Let me give you some examples. 

 

I stupidly chased our walls with a 9" grinder ( because I had it) rather than pay €120 for a days rental of the proper tools. 

 

It took me about 20 hrs of pure torture. 

 

My mate rented the machine and did his house in an afternoon. At €20/hr it stupidly cost me double what his did. 

 

I can lay blocks, but I'm slow and I don't like doing it for more than a couple of hours as I'm too soft. I reckon about 10/hr would be average. That come to about €2/block. Maybe that makes some sense for small projects but no way for a large house. 

 

Gains can be made where you do the donkey work of someone who's more highly skilled. Like UFH pipe laying or pulling cables for wiring. Plumbers and sparkles are expensive laborers. 

 

Another example, my mate, extended a cottage. 4 men took 2 days to crowbar and sledge down an old stone chimney. All unpaid, family, mates etc. then they took the same again to break out the old floor. Then the same to take off the roof. 

 

Had they hired a digger and demoed the house their mate time could probably have saved them multiples of the cost later in the build. 

 

 

 

 

 

 

 

 

 

 

 

 

I helped my mate for free with the build, pouring concrete, groundworks, airtighess and some basic carpentry. 

 

I didn't do any of the fooling with the manual demolition though. I've learned the long way my time isn't worthless. 

 

I did offer to drive my digger straight through it though. 

Edited yesterday at 22:24 by Iceverge

[allthatpebbledash]

19 hours ago, crispy_wafer said:

Just popping in to say, a neighbour down the road from me refurbed his bungalow last year, roof off, external block and render away, bricked the outer leaf and did an internal refit too and a smallish extension.  Took him 4 - 6 months, but is a builder by trade, so has the benefits of can do, or knows men who can.  

Interesting. That’s 2 I’ve read about now saying it can be done.

 

17 hours ago, Russell griffiths said:

@allthatpebbledash I’m just trying to be a realist

your saying a knock down and rebuild will be more expensive, it certainly will be, but how much better will the final product be, and what is the value of a new build versus your refurbishment. 
 

get some nice street scene pictures done for you and get them valued, you might be surprised how much the new build comes out at. 
 

having spent all my life chopping houses about before I found one to knock down, I will never do a refurbishment again. 
 

if it’s been empty two years I can guess what sort of condition it’s in. 
 

 

 

For it being empty, I bought it as long term family home. Never moved in as we planned a remodel. But then remodel came in pricey with not much space gained so I went in with an application for a full demo and rebuild, but larger footprint. The planners were having none of it. I either rebuild to same footprint more or less, or refurb it. So now I’m back at refurb. But this time plans are to retain almost all the walls, and extend at the rear.

 

Time since purchased to now is just over 2 years now. The property is in good condition, it got stripped out after application 1 got approved and the structural engineer wanted to understand make up of existing walls. This is why it’s sat as a shell now, everything needs putting back in.

 

The future value in this is irrelevant to the discussion. I don’t plan on selling.

 

17 hours ago, Russell griffiths said:

What sort of insulation levels would a refurbishment of this kind need to comply with building regs. 
 

if you take down the outer leaf and extend the cavity to get 100mm of batts inside it then what happens with the wall ties, are they not going to be too short, then what about the lintels, then will this wider wall fit on the footings with the new regs on footing width. 

I was thinking the leaf would sit at same width so footings remind same, and you’d use batts that are 75mm to fit existing cavity?

 

17 hours ago, Canski said:

Oh thanks. I can’t bring myself to build them for a loss. Maybe the same applies to the OP. We all know it would be a better house if demolished and rebuilt but I doubt if the numbers would add up.

 

This is where I got stuck. I previously did look at demo and new build, but the planners wanted it to be same footprint near enough. I couldn’t overcome the cost of demo, new footings, only for house to be of same size? 
 

That’s not including the fact if I go back in now to say we will demo and rebuild as planned for the refurb, the application would take another 12 months? 
 

17 hours ago, saveasteading said:

 

Correct. The strength of  a single skin is much less than half of the double skin.  It would need temporary support during the work. THe support gets in the way.

You would not live in the house while this was happening, and should move heavy furniture out.

A new outer skin could be tied using brackets screwed to the inner wall: that is the least of your issues.

 

It's not only structure though.

Do not ignore the detailing at the foundation ( does the widened wall fit on it still?)

Or at the roof. How does this new outer face line work with the current eave and gutter...you probably have to extend the roof at eaves and gable.?

And at doors and windows?

 

I wouldn't dream of doing this. Not with my house and my money anyway.

New roof going on. Can be put on same footings so no increase in cavity? If few sections at a time are put on support, built up, and move along to next, surely it’s possible? All new windows and doors, lintels, and ground plus intermediate floor. Does this change things?

 

11 hours ago, Iceverge said:

I cannot emphasis this enough. There'll always be more work to do than one person can manage and you need a metric to value your time. £ or € or $ is a pretty good one. 

 

Let me give you some examples. 

 

I stupidly chased our walls with a 9" grinder ( because I had it) rather than pay €120 for a days rental of the proper tools. 

 

It took me about 20 hrs of pure torture. 

 

My mate rented the machine and did his house in an afternoon. At €20/hr it stupidly cost me double what his did. 

 

I can lay blocks, but I'm slow and I don't like doing it for more than a couple of hours as I'm too soft. I reckon about 10/hr would be average. That come to about €2/block. Maybe that makes some sense for small projects but no way for a large house. 

 

Gains can be made where you do the donkey work of someone who's more highly skilled. Like UFH pipe laying or pulling cables for wiring. Plumbers and sparkles are expensive laborers. 

 

Another example, my mate, extended a cottage. 4 men took 2 days to crowbar and sledge down an old stone chimney. All unpaid, family, mates etc. then they took the same again to break out the old floor. Then the same to take off the roof. 

 

Had they hired a digger and demoed the house their mate time could probably have saved them multiples of the cost later in the build. 

 

 

 

 

 

 

 

 

 

 

 

 

Great advice once again lad.

 

Here’s how I’m looking at it.

 

Currently it’s sat as a shell.

Everything needs putting back in.

Planning approval for refurb only.

Tax at 5% or nil rated for some items.

New build application would take another 12 months or so, I presume.

Cost of demo/excavations and new foundations I estimate will be high in current climate.

Existing masonry shell probably has a built value of £100k at least.

To demo (circa £20k), new foundations (circa 40k, based on nearby friends build).

 

I’m effectively looking at £200k cost to get back to where it stands now? Or have I missed something?

 

[saveasteading]

12 hours ago, Mike said:

But if you do decide to renovate

What a good summary. Save it  for future discussions on the subject.

 

In brief? A biggish business would demolish. A little builder might do a cheap tart up and pretend to live in it, a real diy can look after details and quality, and phase the work with lots of disruption. It is about cash flow.

[Iceverge]

Any pics to see what you're dealing with? 

 

The strip out and trouble you've gone to with planning thus far might lead you down the sunk cost fallacy. Beware. 

 

 

 

 

[lookseehear]

Shouldn't there be some consideration for the carbon implications of demolish and rebuild? It's difficult for the average person to quantify but it definitely was a factor when we looked at this. There's some legitimacy to the idea that you shouldn't knock down a structure that is otherwise sound. It isn't always all about the pounds and pence, particularly given there's uncertainty whatever route you go down.

[Mike]

8 hours ago, allthatpebbledash said:

I either rebuild to same footprint more or less

Though you may be able to add useful m² by building a basement, subject to permission.

 

8 hours ago, allthatpebbledash said:

New build application would take another 12 months or so, I presume.

Theoretically 8 weeks from submission, but you'd need to check out other local applications to get an idea of the reality.

 

4 hours ago, lookseehear said:

Shouldn't there be some consideration for the carbon implications of demolish and rebuild? ...There's some legitimacy to the idea that you shouldn't knock down a structure that is otherwise sound

Yes, that is a factor, but a difficult one.