Base plate with different heights

Hello everyone,

I am planning a solid house with the following data:
Main house with two full stories and a pitched roof, adjoining side house with garage on the ground floor and pitched roof, connected in a T-joint.
The floor of the ground floor of the main house should be higher than the floor of the garage, hence the idea to pour the base slab at two different heights.
That means the entrance of the main house should be accessible via two or three steps.
Now I have two questions:

1.) Is pouring a two-level concrete slab common and how is it practically implemented?
2.) The clinker facade runs all around on the base slab but should also start at the very bottom of the main house (otherwise the base slab protruding above ground would be visible?!), how can that be realized?

Answers like: "Just ask the architect/structural engineer" are no help to me. I have set myself the goal to plan the house from scratch and acquire the necessary knowledge.

Thank you very much for your help!

Hello Landhausbauer,

we are currently building a semi-detached house with a total of 3 different heights, ergo 3 floor slabs. This is certainly not very common, but absolutely doable. It will depend on you getting a good shell builder. What kind of foundation recommendation do you have in your soil report? For us, a floating slab foundation was executed on an 80 cm gravel cushion.
The different heights were established at the subgrade and with the gravel packing. First, the lowest floor slab was poured and then the ground floor was built up. On the side towards the other two floor slabs, it was meticulously sealed and insulated. Then the second floor slab was placed “against it” and at the same time an additional strip foundation was made at the first and lowest one for the third and highest slab. After formwork removal, sealing and insulation followed again. Finally, the third floor slab was poured together with the split-level stairs connecting the last two slabs.
Honestly, I would advise against planning this alone. Our architect made a very detailed execution plan and I witnessed the intensive coordination with the shell builder. There were also occasional head-scratching and questions on the construction site. It’s not that simple on its own.
Regarding the clinker question, I can’t say anything as I have no idea about that. With different heights, you have to carefully consider how to design the base so that it doesn’t look strange. Just post a hand sketch of how you imagine it.

Thank you very much for the help and the detailed insights! Of course, an architect/structural engineer should/must review it in the end, but I hope that my drafts have the necessary maturity to avoid major changes afterward. As a supplement, below is a model of the floor slab as I currently envision it. It can be seen that the floor slab is only elevated in the inner area of the main house. Additionally, the bricks of the exterior wall are indicated. For the completion to three-layer masonry (as currently planned), insulation and clinker bricks are to be applied to the lower step (same height as the garage). This means there is no step for the insulation and clinker bricks, and the same height runs all around the house -> no visual problems. I see it as problematic that the step of the floor slab must be exactly the same height as one brick.

Best regards

exactly

This is an unpronounceable word in construction...

Don't actually bother figuring it out on your own. You are too much of a layperson and have no idea about the subject matter. Better to plan together with the architect and use the time for other things if you want to get deeply involved in the construction. After all, an architect had to study for it, which you want to learn on the side.

Planning and execution are two completely different areas. You can plan well on your own, but the architect and the craftsmen must then professionally implement your plan into a house.

That means the main house entrance should be accessible by means of two or three steps.

At first, that sounded like a bigger difference than the drawing now shows. Different thicknesses / heights of floor slabs are not unusual in themselves – if only because it is common in the garage not to have underfloor heating.

I am usually good at marking and linking threads, but in this case I can only say without links that the topic of terrain-following cladding boundaries is not uncommon, but is discussed several times a year – mostly in connection with houses built on slopes.

Would the floor slab be seamless according to your idea? – and anyway: is there a plot of land whose buildability has already been checked against your building concept?