Hello everyone.
My building applications and calculations are all approved, and now construction is starting.
It is a single-family house that I am attaching offset to my existing detached single-family house for my parents. (Overlap only 3m (10 feet)).
So, it can almost be considered another detached single-family house.
The footprint is about 70m² (750 sq ft) with a flat roof (prefabricated concrete) and no basement.
The ground slab is 15cm (6 inches) thick with strip footings measuring 30/80cm (12/32 inches) and 30/40cm (12/16 inches).
Yesterday, my earthworks contractor removed approximately 20cm (8 inches) of topsoil.
Next week, the entire area (including around the building) will be raised with gravel fill to match the height of the existing house (slightly sloping terrain).
Once this area is compacted in layers, the strip footings will be cast.
For the external walls, 30/80cm (12/32 inches) footings with reinforcement as per structural requirements, and for the internal walls, 30/40cm (12/16 inches) footings without reinforcement.
The floor construction according to the architect: 5cm (2 inches) gravel layer / polyethylene (PE) sheet / insulation (expanded polystyrene foam EPS_035 4cm (1.5 inches)) / 15cm (6 inches) concrete slab / insulation (EPS_035 8cm (3 inches)) with underfloor heating and 7cm (3 inches) screed.
Regarding the strip footings, the architect mentioned insulation extending 80cm (32 inches) deep (below frost line).
However, my builder now says he only wants to install insulation about 20cm (8 inches) deep along the strip footings.
According to him, deeper insulation would be much more expensive because he would have to formwork the footings down to full depth, and the savings on insulation/heating costs would never cover that.
I have spent hours researching but haven’t found satisfying answers. On the contrary, I have even come across reports suggesting insulating the interior sides of the external footings as well as internal footings on both sides.
How would you approach this?
Attached are a photo of the site conditions and a building plan.
Regarding the photo, the finished floor level of the existing building is at the black plinth edge; the finished ground with paving later will be approximately -0.32m (1 foot) or about 5cm (2 inches) below the top of the boundary wall to the neighbor.
My building applications and calculations are all approved, and now construction is starting.
It is a single-family house that I am attaching offset to my existing detached single-family house for my parents. (Overlap only 3m (10 feet)).
So, it can almost be considered another detached single-family house.
The footprint is about 70m² (750 sq ft) with a flat roof (prefabricated concrete) and no basement.
The ground slab is 15cm (6 inches) thick with strip footings measuring 30/80cm (12/32 inches) and 30/40cm (12/16 inches).
Yesterday, my earthworks contractor removed approximately 20cm (8 inches) of topsoil.
Next week, the entire area (including around the building) will be raised with gravel fill to match the height of the existing house (slightly sloping terrain).
Once this area is compacted in layers, the strip footings will be cast.
For the external walls, 30/80cm (12/32 inches) footings with reinforcement as per structural requirements, and for the internal walls, 30/40cm (12/16 inches) footings without reinforcement.
The floor construction according to the architect: 5cm (2 inches) gravel layer / polyethylene (PE) sheet / insulation (expanded polystyrene foam EPS_035 4cm (1.5 inches)) / 15cm (6 inches) concrete slab / insulation (EPS_035 8cm (3 inches)) with underfloor heating and 7cm (3 inches) screed.
Regarding the strip footings, the architect mentioned insulation extending 80cm (32 inches) deep (below frost line).
However, my builder now says he only wants to install insulation about 20cm (8 inches) deep along the strip footings.
According to him, deeper insulation would be much more expensive because he would have to formwork the footings down to full depth, and the savings on insulation/heating costs would never cover that.
I have spent hours researching but haven’t found satisfying answers. On the contrary, I have even come across reports suggesting insulating the interior sides of the external footings as well as internal footings on both sides.
How would you approach this?
Attached are a photo of the site conditions and a building plan.
Regarding the photo, the finished floor level of the existing building is at the black plinth edge; the finished ground with paving later will be approximately -0.32m (1 foot) or about 5cm (2 inches) below the top of the boundary wall to the neighbor.
1. No, I have not had a soil survey carried out.
3+4. This is how it was calculated by the architect; it is supposed to be for insulation purposes.
There will also be insulation, underfloor heating, and screed on top of the concrete slab.
5. The concrete slab is designed with two layers of reinforcement mesh (with layout plan) and a thickness of 15cm (6 inches).
It is a single-story flat-roof detached house, basically a bungalow with a precast concrete ceiling.
3+4. This is how it was calculated by the architect; it is supposed to be for insulation purposes.
There will also be insulation, underfloor heating, and screed on top of the concrete slab.
5. The concrete slab is designed with two layers of reinforcement mesh (with layout plan) and a thickness of 15cm (6 inches).
It is a single-story flat-roof detached house, basically a bungalow with a precast concrete ceiling.
Similar topics