Cultivation - Cost Estimation

  • Erstellt am 2016-01-11 16:29:24

Xorrhal

2016-01-11 16:29:24
  • #1
Hello everyone,

after my "plan" for a new build drifts into the distant future due to various factors, I am now planning to extend my existing house and am trying to get a rough overview of the costs.

The existing house has a ground floor with approximately 90m² of living space and an extension of about 70m². My parents live on the ground floor and will stay there (in case anyone gets the idea to say "just swap"). The old building has a basement. On the upper floor of the old building there is basically the same apartment again (that's where I live).

The extension was planned 20 years ago so that it would be easy to add another floor. So as far as static loads are concerned. The roof "only" has to be removed, the ring beam in the rear part raised by about 1.5 meters, and a corresponding intermediate ceiling inserted. No additional support columns or anything like that are necessary.

The new extension should include a bathroom, the kitchen, a living/dining room as well as a balcony. Possibly a bedroom instead of the kitchen, though then the kitchen would have to be placed in a room in the old building where there are no connections – and I didn't really want to tear up the entire old building. The new bathroom could be connected to the existing pipes using a core drilling, so minimal destruction would occur.

I asked an acquaintance with architectural "skills" what I should expect in terms of costs. He said an extension is basically like a new build, and I should expect about €1800 per m² of living space. Is that realistic?

How would you roughly classify the costs for the following points (in parentheses my layman’s estimates):

Ring beam masonry (€2,000 with own work)
Inserting intermediate ceiling (€20,000)
New build masonry (€10,000 with own work)
Windows (€20,000)
Roof including facade (€30,000)
Sanitary including bathroom and underfloor heating (€20,000)
Building services (electricity, network,...) (€8,000 with own work)
Flooring, walls, wooden ceiling (€15,000 with own work)
Additional costs (€15,000)

Total: €140,000

Does this sound realistic? Or is something estimated far too far from reality?
 

Xorrhal

2016-01-14 12:40:15
  • #2
Nobody has an opinion on this? Come on, so much concentrated expertise can surely make a statement about this, right? And if anything is unclear, I am happy to answer your questions
 

Bauexperte

2016-01-14 13:34:16
  • #3
Hello,


No one can reliably answer these questions for you; there are too many question marks.

I would first recommend talking to a structural engineer; regardless of whether an extension was taken into account back then or not. Unless the structural analysis clearly shows that an extension can be done safely. Maybe the structural engineer from back then is still practicing? You can also clarify there what impact the extension has on the existing building (possibly changing the roof).

Have you clarified with the building authority responsible for you whether you are allowed to extend at all?

Then you need a carpenter (possibly a demolition contractor) who will dismantle the old roof and can reliably tell you whether you can reuse wood like roof tiles; provided it is his area of expertise. If clay roof tiles were used, this might be a tricky question as these parts are quite fragile, not good for dismantling; craftsmen are not fine mechanics.

I read a lot about EL; for the trades of plumbing/electrics a master craftsman is required; companies that allow EL in the desired form as well. In this context, you can also clarify whether the existing heat generator is designed for the increased heated living space and/or whether a replacement is necessary.

Regardless of the costs of dismantling, I would estimate that the extension would cost you around EUR 115,000 (excl. painting/flooring work) if you outsource all necessary work. How much of this can be saved within the scope of EL will depend on your negotiations.

What do you understand by the item ancillary costs?

Rhenish greetings
 

Xorrhal

2016-01-14 14:39:51
  • #4
Hello and thank you very much for your explanations!

The architect who was here said that according to the construction plans he doesn’t see any problems with the statics, if necessary intermediate beams could be installed. Of course, he will consult a structural engineer when the concrete planning begins. But he said he sees no problems at all – and that was also the requirement given to the architect back then.

I haven’t spoken with the building authority yet either, but here too the architect said there would be no problems. On the one hand, everyone in the street already has mostly a two-story extension by now, and we have already added one floor. The footprint will not be changed. No part of the extension will be higher than anything surrounding it, so significantly lower than the old building, not higher than the extensions above or below our property. We won’t take anyone’s light or anything like that. But of course we will also obtain the necessary permits here. If an architect, whom I claim knows his stuff, tells me there are no problems, then I just believe him, especially when it’s not yet about concrete planning.

At the moment I just want to roughly define a very basic financial framework so that I can ask the bank for corresponding financing. If I cannot give the mortgage advisor a figure, he won’t respond – at least that’s been my experience so far. In addition, the existing house still has encumbrances from the purchase and financing. And I want to incorporate that into the financing (in 2019 I’ll have to refinance a loan and want to combine it with the new financing, if possible).

For the roof dismantling I would simply assume that I can’t reuse anything. Just because the tiles used are not allowed for a lower roof pitch than currently. And that will necessarily be the case. So I have to reckon with a completely new roof here, and I’m planning with the above-mentioned EUR 30k including the facade (I hope so). Disposal can probably be arranged quite cheaply by my father.

For own work I was thinking of the following:

- Removing the roof covering (since the tiles need to be disposed of anyway)
- Interior finishing such as wallpapering, wood ceiling, laying tiles (the entire floor in the house is tiled, all laid by ourselves)
- Breaking through the walls to the old building and all related work around it (so that the passage is “finished”)
- Preparatory work for electrical installation (“chasing,” setting boxes, laying cables,…) so that the electrician just has to connect
- Preparatory work for sanitary installation (drilling, plaster work,…)
- Preparatory work for the underfloor heating (laying the plastic mats into which the pipes for underfloor heating will go – we also did this ourselves in the rest of the house)
- Painting work

By incidental costs I understand the costs of the architect, costs for permits, costs for things like “floor protection during the dismantling of the old roof,” builder’s insurance, notary costs for the financing (land charge registration) and such things…

EUR 115k sounds somehow very little to me. I had (okay including dismantling etc.) calculated EUR 140-160k – and the own work is already deducted from that.

Do you really think I could get by with that?
 

Bauexperte

2016-01-14 16:01:49
  • #5

TEUR 15 would, in my opinion, already include a buffer for the above, unless the architect overcharges. So all good.


Yes. Plus costs of dismantling and additional construction costs.

Rhineland regards
 

wpic

2016-01-14 16:08:08
  • #6
Commission the architect you trust with a building inquiry (§34 Building Code) or directly with a preliminary draft if a development plan exists, along with a cost estimate or directly a cost calculation by trades. Then you will have all your questions comprehensively answered and the crystal ball can stay in the cupboard.
 

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