ᐅ Costs of Different Types of Houses

Hello everyone,

I have just started reading up on the topic of building a house, even though the desire to do so is still quite vague at the moment. This is more likely to be a project for the next five years. I feel like I’ve already spent dozens of hours here in the forum 🙂

Right now, I’m trying to get a sense of what makes a house expensive, which things are energy inefficient, and so on. That’s why I’m interested in whether there are any general guidelines for comparison.
Disclaimer: I understand that it always depends on the individual situation. Nevertheless, I could imagine that some rough rules of thumb have become established.

• First of all, I would like to know: how does a bungalow compare to a house with two full stories? (In terms of costs and the effort to achieve a KfW standard). My youthful recklessness tells me that a bungalow is cheaper to build but more expensive to insulate because of the larger ground/exterior surface area.
• The same question applies to a two-story house compared to a 1.5-story house (I know, that doesn’t really exist ;-) ) with knee walls but no attic.
An attic is certainly great for storage, but initially it’s dead space that requires an additional intermediate ceiling and more exterior surface area.

• Also, I like the idea of an L-shaped (living room) layout with a terrace nestled inside the inner corner.
Does deviating from a cubic shape significantly affect the price? I would assume that especially if aiming for KfW standards, this could get tricky because corners are presumably complex to insulate. Or are these just minor issues?

• The same question comes up regarding dormers and possibly a third or fourth gable.
• How much does the roof pitch affect price and energy efficiency? (My assumption: a flatter roof uses less material and also exposes less surface area).

One more disclaimer: I am not trying to plan the cheapest possible house. Nor do I want to optimize every decision solely for KfW standards (I don’t even know yet whether I want or need KfW certification).
I’m just trying to get a feel for how building decisions influence cost and energy efficiency. After all, I don’t want to plan something completely unrealistic. When it gets more concrete, of course, I’ll consult an architect.
Until then, I want to build some background knowledge.

Thank you & best regards from the cave.

Welcome to the forum,
you will find answers to your fairly general questions just by reading through. In short: the more complex the house, the more expensive it will be.
In general, the plot determines the house:
plot size, building regulations/building codes, developer, neighboring buildings, slope yes/no, nice view, and so on.
When the time comes, introduce your plot along with a completed questionnaire, and some members will be happy to offer advice.

A bungalow is definitely more expensive in many ways (probably not regarding KfW financing):
- larger foundation slab
- more roofing

But it also has many advantages:
- no stairs (except to the attic, which is mostly used as storage space)
- if you install a rainwater cistern, you get a much higher water yield
- larger roof area for a photovoltaic system
- faster to build than a two-story house because you don’t need to lay screed on the attic floor, eliminating one drying time

In terms of KfW financing, it probably isn’t much more expensive than a two full-story house, since the wall area (sqm) is likely about the same, so the costs are similar. But this is just a layperson’s estimate. There are surely more and better experts on this topic 😎

Generally speaking, building upwards is always more cost-effective than building outwards. Whether it’s one-and-a-half or two stories makes no difference.

You have identified the main cost drivers well.

The biggest problem will be your 5-year lead time if price trends continue as they are.

Acof1978 schrieb:

Faster to build than a two-story house since you don’t have to lay screed on the attic floor and the drying time is eliminated once.

It’s true that it’s faster to build, but the explanation is nonsense because the screed is just laid all at once and then dries in parallel anyway. Or did you mean the drying time of the ground floor ceiling? That only applies of course to conventionally built houses. In timber frame construction, this doesn’t matter.

Otherwise, I go by geometry: the most efficient building shape in terms of the ratio between surface area and volume is a sphere – but that’s difficult to build and live in, so the next best option is a cube. The more you deviate from that, the more exterior surface area you have to create for the same volume (simplified: living space). Viewed this way, a classic two-story house (with a flat roof) is already close to optimal. However, many other factors and details come into play, which significantly distort this seemingly simple picture. That’s why, despite all the logic, I mainly went with what I find visually and practically appealing. In the end, the differences in price aren’t as huge as you might think.