Demolition and Rebuild Under Permitted Development?

[strangebudgie]

Hello, newbie here. I hope someone with knowledge of PD regulations can help me? Next to my house I have a detached Victorian rectangular 10m x 5m outbuilding, previously used as a Blacksmiths Forge. It is an attractive period building, but not listed. I have had approval from my council for renovation and conversion into a Granny Annexe under Permitted Development. So far so good, and a structural surveyor judged that much of the original building could be preserved albeit with a lot of underpinning and strengthening of roof and walls. However, I have had two builders so far offer their quotes and both are of the opinion that the building could be dangerous to work on in its current state, plus it could be a 'money pit' and that it essentially needs demolition and rebuilding (where possible using recycled materials from the demolition). Does this fall under the scope of 'renovation' under PD or would I need to apply for full planning permission? We intend to rebuild on the existing footprint so that externally it is pretty much identical to the original building. Any advice gratefully received!

 

[freddiemercurystwin]

Once you demolish something it is no longer there, therefore anything replacing it, even if absolutely identical is considered new construction and is subject to planning consent if it is not permitted development.

 

[jacko555]

I wonder where the line is before it's considered demolition vs renovation?

Genuinely wondering, not suggesting.

E.g., if you took the roof off and 3 of the 4 walls out, say leaving the front wall largely intact, rebuilt the 3 and roof sympathetically etc.

Is that still permitted development? Would anyone notice?

 

[^woody^]

Get your "structural surveyor" to prepare a schedule of work and get quotes for that. That way, you are telling the builders what you require them to do, and not the builders telling you what they would rather do.

CDM regulations apply, so either your designer manages the health and safety, or your builder does. Either way, they should prepare risk assessments to define the risks, and method statements to detail how they will work safely.

If this building is not actually falling down now, then it can be refurbed and your two builders are more interested in making more money from you and an easy build.

 

[^woody^]

I wonder where the line is before it's considered demolition vs renovation?

Genuinely wondering, not suggesting.

E.g., if you took the roof off and 3 of the 4 walls out, say leaving the front wall largely intact, rebuilt the 3 and roof sympathetically etc.

Is that still permitted development? Would anyone notice?

If a "substantial" part of the original is replaced, or altered, either at once or in stages, then the resulting structure is deemed not original and new.

"Substantial" depends on the specific circumstances, and can be influenced by the appearance as well as the actual amount of new work.

 

[Nakajo]

These days, we don't do demolition, merely dismantling.

 

[strangebudgie]

Get your "structural surveyor" to prepare a schedule of work and get quotes for that. That way, you are telling the builders what you require them to do, and not the builders telling you what they would rather do.

CDM regulations apply, so either your designer manages the health and safety, or your builder does. Either way, they should prepare risk assessments to define the risks, and method statements to detail how they will work safely.

If this building is not actually falling down now, then it can be refurbed and your two builders are more interested in making more money from you and an easy build.

Hello, and thanks for your reply. I have had a schedule of works and construction notes, including building regs, completed for the job by the architect and surveyor. One builder was more sympathetic to the refurb idea, but the other less so. He commented that the surveyor had "obviously never done any building". His main point of contention was that the surveyor had recommended localised underpinning, whereas he felt the whole structure needed underpinning support (we are on clay soil and there has been considerable movement in the past). I like the building, it has a lot of history and I am keen on preserving it as best I can, but this sowed seeds of doubt in my mind as to the best course of action. I am also conscious of money factors; the architect/surveyor said that it would be cheaper to refurb, but both builders (who have come well recommended) have both advised that it would be cheaper to dismantle and rebuild.

 

[wessex101]

His main point of contention was that the surveyor had recommended localised underpinning, whereas he felt the whole structure needed underpinning support (we are on clay soil and there has been considerable movement in the past). I like the building, it has a lot of history and I am keen on preserving it as best I can, but this sowed seeds of doubt in my mind as to the best course of action. I am also conscious of money factors; the architect/surveyor said that it would be cheaper to refurb, but both builders (who have come well recommended) have both advised that it would be cheaper to dismantle and rebuild.

If it is an old period forge why does it need underpinning? Old buildings tend to have shallow foundations but they have survived for many decades like that so unless you are undertaking alterations that concentrate loads in small areas or something has changed such as large trees have grown up or drains are leaking they rarely need underpinning.

Is the surveyor sure that the "movement" is due to subsidence and not other structural forces?

In defence of the builders underpinning and localised structural repairs can be very time consuming and labour intensive and therefore expensive so sometimes demolition and rebuilding can be more cost effective, especially if VAT comes in to play. (new build residential building should be VAT zero rated)

And in answer to your original question, I 100% agree with Freddy. You would need a planning application for demolition and rebuilding.

 

[mrrusty]

Why the resistance to planning? If it's a like for like size and there's nothing controversial it should go through. I've just put a planning application in for a garden room and it cost grand total of £234. You'll likely save that.

It depends how much you want to preserve the original construction. Personally, if it's lime mortar and is "loose" construction, I'd dismantle it myself, clean up the materials, and then start again - proper footings, and then re-use as much material as you can and rebuild it in the same style. I agree with builder 2 - it's going to be easier to rebuild on nice straight new footings than it is to try and fiddle about with local underpinning.