this topic is difficult ... a smaller double casement window is not enough; changing the base plate aka strip foundations for the garage is cost-neutral. That is why I am trying the opposite approach. Attached you will find a single-family house with many gimmicks, which have to be seen as cost drivers.
In the original plan, white Kämpfer elements were planned in the rooms bathroom + guest of the attic; in reality, the colored parapet windows with beveled corner shown in the view (matching the roof slope and rear view) were installed. Additional "disadvantage" – a cheap roller shutter cannot be installed with these windows.
The covered front entrance costs extra; nice to operate the door lock with dry feet, but also more expensive. The continuously recessed front entrance is treated like an exterior wall; roughly 2.5 sqm of additional surface to plaster.
The attached bay window – used as a balcony in the attic – requires a more expensive base plate; an increase in floor-to-ceiling windows as well. The recess on the right in front of the kitchen on the ground floor was built over in the attic; this generates additional costs for insulation, as well as for the support pillar and its anchoring in the ground. The balcony requires – besides a frost-proof slab covering – fall protection, so costs arise for a railing. In the example, a railing made of stainless steel was chosen, still the currently affordable alternative.
The installed landing staircase is significantly more expensive than a standard spiral staircase. Additionally, in the example house it was executed as a concrete staircase with a masonry handrail and granite covering.
In summary, it can be said that a single-family house can be built "inexpensively" – which strongly depends on the federal state and its respective land and construction prices – if
[*]a as level as possible plot is purchased
[*]built on a base plate
[*]built according to the applicable energy saving ordinance
[*]a straightforward architecture with a gable roof is chosen
[*]the story height is not changed
[*]a standard staircase, as a stringer or bolt staircase, is installed
[*]complex window constructions are avoided
[*]manual roller shutters are chosen
[*]the standard (sanitary, tiles, etc.) of the preferred provider is accepted
[*]painting and floor coverings are executed as basic packages (EL)
[*]external expertise (e.g., TÜV®) is purchased
Where the question always has to be clarified, what is "inexpensive"? A single-family house with a size of 130 sqm is – considering the total investment – cheaper than a single-family house with a size of 100 sqm, just as a single-family house of 180 sqm does not have to be exorbitantly more expensive. One provider is, for example, cheaper with their ETICS than one who offers monolithic construction and vice versa; it always depends on the respective purchasing conditions. The carpenter from the next town might be cheaper in his offer than the well-known prefab house provider from advertising, the joiner in his kitchen offer cheaper than Meda Kitchens (named by way of example), etc.
If a fundamental statement can be made at all, it is that the provider – regardless of construction method – who offers a medium standard through their construction description is not the worst choice. Everything that looks like a bargain upfront is mostly very expensive in the end. No one, but really no one, has anything to give away.
Rhenish greetings
