Cost estimation for expansion and renovation before house purchase

Hello everyone,

we have been looking for a house for a long time and have finally found something suitable.

From a layman's perspective, the building fabric is good (a detailed inspection by an expert still needs to be carried out). We really like the location and the plot. However, the attic is not developed and therefore the living area is too small for the four of us.

We would carry out the following work:
- install a dormer on the entire south side of the roof
- convert the attic (3 bedrooms + bathroom)
- ground floor: remove two walls and build a new one
- renovate the ground floor

Before purchasing, we would like to know the expected costs. I would have the planning and cost estimation done by an architect.

My question to you specialists is whether this makes sense, or should I rather have the conversions offered by two to three specialist companies? Or should I take a different approach?

Thanks

Best regards, Thomas

- Install a dormer on the entire south side of the roof

Is that allowed according to the development plan? Often, dormers are limited to 2/3 (or otherwise) of the roof area.

The expert might possibly provide a rough estimate of the costs?!

Good evening Thomas,

Before purchasing, we would like to know the costs still to be expected. I would have the planning and cost estimation carried out by an architect. My question to you specialists is whether this makes sense, or should I rather get offers for the conversions from two to three specialist companies? Or should I rather take a different approach?

I am not very familiar with Bavarian building law, but I would say that with such extensive renovation work as you have in mind, nothing will proceed without involvement of the authorities. Accordingly, you need help from someone who knows about this, and that is an architect.

First and foremost, however, you need expert support, help that first enables you to decide whether you want/can buy the property. This is an expert (specialist) experienced in the evaluation of existing properties. This expert will tell you relatively quickly and frankly what renovation costs you can expect if you want to bring the property into a long-term livable condition. In the first step, he will also be able to provide you with a rough cost estimate that includes the approximate costs of your conversion measures.

If you arrive at a figure this way – sum of purchase + ancillary purchase costs + renovation + conversion – with which you can live, you should talk to one/two/three bankers/finance brokers/insurers you trust and – if this conversation also goes positively for you – initially finalize the purchase. The next step is then to look for and commission an architect and then obtain offers. Whether these are craftsman businesses for the respective trades or companies specializing in renovations is up to your decision, because both have advantages and disadvantages; as always in life ;)

Rhenish greetings

You can first get information about possibilities for (re)building permits and check the development plan for free - at the city office. Make an appointment and go there, don’t just call. During the conversation, you will surely come up with more questions.

Not free, but very useful is a building inspector. Of course, you can first visit the house alone and then, if you think it is suitable, bring an inspector along on a second visit. They often charge around 200-300 euros (if you really buy the house, their advice and assessments are valuable, and if they save you from buying a pig in a poke, you can save a few hundred thousand), it is definitely worth it.

Depending on the year of construction, there might be a risk that asbestos was used somewhere in the house - and renovating or removing such material will be VERY expensive, as there are very strict laws in Germany about which specialized companies are allowed to remove it (you won’t believe it, in the Netherlands you are allowed to do this yourself, you just have to double-bag the toxic panels and then have them collected by the municipal waste service - no one checks whether you might contaminate the entire environment by not working cleanly).

Otherwise, the biggest danger in existing properties is penetrating moisture (which can lead to mold growth, that depending on the type of mold not only poisons the indoor climate but can even attack the building fabric itself) - a moisture meter is something a good building inspector would certainly bring along.