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When to suggest tearing down and rebuilding a structure?

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Robbiee

Structural
Jan 10, 2008
285
Hello,
When a client asked you to carry out a condition assessment of his building and provide your opinion on the options of tearing down and rebuilding versus renovating. Assuming the building functionality is still satisfactory, what are the criteria for favoring one option over the other one?
I am thinking of having a certain annual maintenance cost that if exceeded, then rebuilding needs be chosen. But really what is that annual maintenance cost threshold? I don't know
Any comments and other ideas are appreciated.
 
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Yes maintenance costs and frequency would play into it. Also, upgrades/renovations required at this stage to suit the clients requirements should be accounted for. Generally it's cheaper to install stuff in a new building when compared to renovations.
 
Robbiee:
When will major mech. systems in the bldg. need major rework or replacement, same for major structural components, ext. cladding and roof system, etc. These are major condition and component assessments over and above normal maintenance. What are their costs and present value as compared to a new bldg. and its present value. Also, have a long discussion with the client about their future plans and potential for renovations, different uses and bldg. loads, etc., and their potential costs. Consider that at some renovation threshold you usually have to pretty much bring the whole bldg. up to current code stds. and this can get expensive fast. Once you’ve determined that the bldg. is structurally adequate and not falling down, this really becomes a costs and present value problem for the owner to resolve with his financial people.
 
One "go/no go" guideline is to compare repair / renovation cost versus replacement cost. When repair / renovation cost exceeds 50% of replacement cost, go with replacement.

[idea]
 
Structural items I frequently run into that play a part in any recommendation I give are:
[ul]
[li]How well the current physical environment is as compared to modern preferences; i.e 8' ceilings are no longer desired or too many interior columns etc.; I am less inclined to do major upgrades to an old model T; when I am done, I have an old Model T that still runs 35 mph but has air conditioning and power steering [/li]
[li]what is the current condition of the major structural components such as 100 year old masonry or wood floors and roofs that have had years of termite or water damage; I am working a project now that the Client keeps running into issues related to the age and dilapidated condition of the major parts of the structural system[/li]
[/ul]
 
Thanks all.
I think the 50% guideline is good and it can be justified by the fact that the renovated building will still need annual maintenance increasingly higher than that of a new building for many year to come, or maybe forever.
 
Sometimes local rules will allow existing construction that is outside the current rules (not strength, more building regulation like boundary distances and heights) to stay outside under renovation. But require adherence to the current rules for a new build. This may influence the decision.

Otherwise, you get a lot more for your dollars in a complete replace comapared to renovate normally along with a better and more functional layout. So unless there are period features etc that someone wants to keep, definitely the 50% rule or even less.
 
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