ᐅ New Construction: Doing Heating and Plumbing Work Yourself?

Hello everyone,

We are planning a new build and are considering handling the heating and plumbing ourselves instead of going through the general contractor.

The reason is that we can get heating (underfloor heating), ventilation system, air source heat pump, and plumbing products at a relatively low cost, but we would need to find a tradesperson to install everything. We are not able to do the installation ourselves.

On one hand, this would likely save us money, but on the other hand, I have concerns for the following reasons:

- I’m not sure exactly when the heating/plumbing package is scheduled during the build, meaning I would need to be flexible with ordering materials and the tradesperson’s time. Is this possible?
- Who takes on the liability? The general contractor does not.
- What happens if I cause a delay?

Does anyone have experience with this topic and can offer advice?

Thank you very much and best regards!

Does anyone have experience with this?

Häuslebauer36 schrieb:

The background is that we could get heating (underfloor heating), ventilation system, air source heat pump, and sanitary products relatively cheaply,

Can’t everyone do that?

Häuslebauer36 schrieb:

then we would have to arrange a tradesperson to install it. We can’t do it ourselves.

Then try to find a tradesperson who won’t use their own materials, because

Häuslebauer36 schrieb:

- Who takes liability? Not the developer.

the tradesperson has to take it. I would charge a lot for that, or simply refuse to do it.

Häuslebauer36 schrieb:

I’m not really sure when the heating/sanitary package will be installed, meaning I need to be able to order materials and a tradesperson flexibly. Is that possible?

It’s possible, yes. But which tradesperson will agree to a) install materials they didn’t supply and b) wait on your call to come work next week?
If you can store the materials yourself, that problem is at least solved.
I only see tradespeople from classified ads or similar platforms who "can drop by quickly" and install your materials—but in case of problems, they might be unreachable.

Häuslebauer36 schrieb:

- What happens if I delay?

Tough luck, and your house construction will stall. In the worst case, for a long time, because the builder’s scheduled work can’t be done. Then other sites will take priority until your project can continue again.

Overall, this will be difficult. It would be good if you could do some things yourselves (installing underfloor heating yourself plus having it inspected by a tradesperson is already quite common). Putting up sanitary products on the wall is also doable even if you’re not skilled at it.

Standard question: general contractor or project developer?
I could imagine it being difficult for a project developer to remove services because of their warranty obligations, but it’s worth asking. Regardless of whether it’s a general contractor or a project developer, the first negotiation question is how much of the agreed total price you can get discounted and be prepared for potentially unexpected negative answers.

What does "relatively inexpensive" mean?
Is it at the same base cost as the tradesperson? Or even cheaper? I’m not asking why, just the question of scale. So first determine the maximum possible savings.

That means the tradesperson is waiving the part of their margin that comes from the markup on materials, takes warranty responsibility for materials even though they don’t have a warranty from their suppliers, and has you as the client/contact person while the rest of the trades are managed by the general contractor?
I’d say the construction market is not yet cooled down enough for you to easily find interested parties here, but that’s just speculation. It’s worth trying—also to see if, in negotiations, the lost material markup is charged back through higher installation prices, which would reduce the calculated maximum savings.

So overall: it’s something you can check, but if in doubt better to review sooner rather than later and not give up too quickly out of frustration, while keeping the trades within the scope of services.

No professional craftsman will do that, at most someone unofficially without any warranty. Who knows what kind of refurbished second-rate goods you might get, even if you believe everything is brand new.

If you fall behind schedule, not only can construction come to a halt, but the construction company could also hold you liable, your fixed price may be voided, and so on.

Any damages and defects that arise later will be blamed on your "own work."

In my opinion, stories like this are only worthwhile if you can do the work yourself (and have the necessary expertise); otherwise, it’s just expenses and trouble with no benefit.

Nice-Nofret schrieb:

In my opinion, these kinds of projects are only worthwhile if you can do the installation yourself (and have the necessary expertise).

Although these are still relatively simple tasks. Installing underfloor heating is mostly a matter of diligence – with continuous installation, the only critical points are the connections to the manifold, where defects become apparent quickly. You also do the pressure testing yourself. The pump for that costs about 20€ to rent.
And fixing plumbing fixtures to the wall is, apart from painting, one of the easiest things to do. However, you are not allowed to run water pipes yourself (even though using a press fitting tool is foolproof).