ᐅ Adding a Bathroom Later in the Attic – What Are the Costs?

I am currently facing the decision of whether to include a fully finished (standard) bathroom, including its own underfloor heating and tiles, but without a bathtub, in the attic (underfloor heating is already installed) in a new build. The cost would be about 15,000 euros. If I skip this for now and decide to add a complete bathroom later after a few years (which I would have fully renovated including tiles and all sanitary installations), would such a retrofit likely end up costing a similar amount or even more? All the pipes, hot water, wastewater, and electrical systems would have to be fully installed afterwards.

From close contacts, I've been advised to leave it out initially and build it later for significantly less money. However, I have some doubts about this advice.

I have absolutely no experience and cannot estimate whether such a retrofit would realistically cost 6,000, 12,000, or even much more.

Thanks in advance!

For me, it would be much more interesting to know whether I will ever actually need the additional bathroom in the attic.

mm56789 schrieb:

All the pipes, hot water, wastewater, electrical wiring, everything has to be fully retrofitted.

You could have the pipes installed in advance and decide later what to do. What is the plan if you don’t install a bathroom there? How will the room be used then?

If the bathroom is located above another bathroom on the floor below, I would have all the pipes routed vertically and capped. If this requires running them across the house, then I would avoid it.

So far, the plan has been that if the bathroom is located in the attic (which would be roughly directly above the bathroom on the upper floor), then the rest of the attic (approximately 60m² (645.8 sq ft) in total) would be used as a bedroom. On the upper floor, there would be no bedroom, only several hobby or work rooms. However, if the bedroom were to be placed on the upper floor, the attic could then be used, for example, as a study or fitness room, plus an additional room. Alternatively, if a child might arrive in about 20% of cases later on, the attic space could be used as a teenager’s room with its own bathroom, so they wouldn’t have to go down a floor all the time.

But it’s already a good idea to have the plumbing installed in advance—I will bring that up. I just wanted to get an assessment. It might also be the case that adding a bathroom later would be very complicated and it would definitely be recommended to include it directly during the new build.

mm56789 schrieb:

then put a bedroom in the rest of the attic (total approx. 60sqm (645 sq ft)). And on the upper floor, no bedroom but several hobby/work rooms. However, if the bedroom is moved to the upper floor, then for example a study or gym plus another room goes in the attic,

So a large and expensive house or solid credit rating. Then finish it exactly as planned for later.

nordanney schrieb:

So a large and expensive house or solid creditworthiness. Then finish it directly as it is intended later.

or there is just an unclear idea of the room layouts. 🙂