Hello everyone,
The first offer from a developer includes an insulated basement:
- "White tank" (25cm (10 inches) waterproof reinforced concrete), with a bituminous waterproofing layer (reduces vapor diffusion)
- Perimeter insulation
- Barrier layer against rising moisture
- Underfloor heating
- Thermal insulation glazing
So, it would be the perfect basement.
The other developer, whose overall package we now prefer, states the following about the basement in the very sparse building description:
Shared (meaning for both semi-detached units) reinforced concrete slab as a waterproof construction ("white tank"). Thermal insulation on the basement ceiling within the ground floor flooring system. Thermal insulation of the slab in the stairwell area. Walls of reinforced concrete, uninsulated or with edge insulation. The basements are not intended as living spaces. Basement as a waterproof structure. Single-glazed basement windows.
There will also be a radiator in the stairwell area in the basement.
In one of the two basement rooms, laundry washing and beer brewing are planned. I intend to vent the brewing odors out through the basement window. Inside this room, I want to plaster with natural hydraulic lime.
The larger basement room is meant to be used occasionally as a recreational space. Maybe a foosball table, a couch, possibly a home cinema setup.
The building description states that condensation cannot be ruled out under unfavorable weather conditions. That doesn't sound very good to me. Honestly, it also doesn’t seem state-of-the-art, but that might just be my impression.
The basement room with the heat transfer station (district heating) will be mechanically ventilated according to the building description. What does that mean exactly? What should one imagine? Wouldn’t that rather bring in high humidity if warm outside air is pulled in during summer? Or could this ventilation even help remove the vapors produced during brewing in that room?
Now my request for help:
What measures can make the basement suitable for living spaces after all?
Is perimeter insulation on the walls sufficient?
Is adding interior insulation later advisable?
What do you think about the insulation of the slab in the stairwell area as described? From the inside? Could this insulation potentially be extended into one or two other rooms as well?
Regarding the laundry and brewing room: Do you see differences in mold risk between insulated and uninsulated basements in connection with water vapor?
Best regards
Ricard0
The first offer from a developer includes an insulated basement:
- "White tank" (25cm (10 inches) waterproof reinforced concrete), with a bituminous waterproofing layer (reduces vapor diffusion)
- Perimeter insulation
- Barrier layer against rising moisture
- Underfloor heating
- Thermal insulation glazing
So, it would be the perfect basement.
The other developer, whose overall package we now prefer, states the following about the basement in the very sparse building description:
Shared (meaning for both semi-detached units) reinforced concrete slab as a waterproof construction ("white tank"). Thermal insulation on the basement ceiling within the ground floor flooring system. Thermal insulation of the slab in the stairwell area. Walls of reinforced concrete, uninsulated or with edge insulation. The basements are not intended as living spaces. Basement as a waterproof structure. Single-glazed basement windows.
There will also be a radiator in the stairwell area in the basement.
In one of the two basement rooms, laundry washing and beer brewing are planned. I intend to vent the brewing odors out through the basement window. Inside this room, I want to plaster with natural hydraulic lime.
The larger basement room is meant to be used occasionally as a recreational space. Maybe a foosball table, a couch, possibly a home cinema setup.
The building description states that condensation cannot be ruled out under unfavorable weather conditions. That doesn't sound very good to me. Honestly, it also doesn’t seem state-of-the-art, but that might just be my impression.
The basement room with the heat transfer station (district heating) will be mechanically ventilated according to the building description. What does that mean exactly? What should one imagine? Wouldn’t that rather bring in high humidity if warm outside air is pulled in during summer? Or could this ventilation even help remove the vapors produced during brewing in that room?
Now my request for help:
What measures can make the basement suitable for living spaces after all?
Is perimeter insulation on the walls sufficient?
Is adding interior insulation later advisable?
What do you think about the insulation of the slab in the stairwell area as described? From the inside? Could this insulation potentially be extended into one or two other rooms as well?
Regarding the laundry and brewing room: Do you see differences in mold risk between insulated and uninsulated basements in connection with water vapor?
Best regards
Ricard0
Thank you for the background explanation. I also get the impression that this developer is trying to stay significantly below the competitor’s price. This is achieved by offering a less comprehensive standard package.
I imagine the insulation of the basement as an optional extra. Ideally, even a central controlled ventilation system for the living area, but I fear the builder or general contractor won’t agree to that.
My rough calculations:
Perimeter insulation of the basement walls: €7000
Insulation of the entire basement floor: €3000 (internal insulation, as with a shared slab foundation, probably nothing else will be possible)
Controlled ventilation system for living areas: €10,000
Is this realistic?
Regarding basement floor insulation, I’m still not entirely sure about its necessity (in terms of moisture in the basement).
Alternatively, only the future living area could be insulated on the floor, while the technical and storage rooms are insulated only on the exterior walls. Could this cause thermal bridges with a risk of condensation, or would that be acceptable?
I’ll also discuss this later with the construction supervisor, but I would appreciate any advice from you.
Regarding the new post by W. Pickartz:
The sales advisor told me during the conversation that this is a very preliminary building permit / planning permission. They only proceeded now to avoid the deadline for the KfW 70 subsidy becoming too tight. Otherwise, everything would have been finalized at the beginning of January, and a proper building permit / planning permission issued.
Best regards
Ricardo
I imagine the insulation of the basement as an optional extra. Ideally, even a central controlled ventilation system for the living area, but I fear the builder or general contractor won’t agree to that.
My rough calculations:
Perimeter insulation of the basement walls: €7000
Insulation of the entire basement floor: €3000 (internal insulation, as with a shared slab foundation, probably nothing else will be possible)
Controlled ventilation system for living areas: €10,000
Is this realistic?
Regarding basement floor insulation, I’m still not entirely sure about its necessity (in terms of moisture in the basement).
Alternatively, only the future living area could be insulated on the floor, while the technical and storage rooms are insulated only on the exterior walls. Could this cause thermal bridges with a risk of condensation, or would that be acceptable?
I’ll also discuss this later with the construction supervisor, but I would appreciate any advice from you.
Regarding the new post by W. Pickartz:
The sales advisor told me during the conversation that this is a very preliminary building permit / planning permission. They only proceeded now to avoid the deadline for the KfW 70 subsidy becoming too tight. Otherwise, everything would have been finalized at the beginning of January, and a proper building permit / planning permission issued.
Best regards
Ricardo
S
Sebastian798 Dec 2015 07:50Ricard0 schrieb:
My approximate calculations:
Perimeter insulation of the basement walls: 7000€
Complete insulation of the basement floor: 3000€ (internal insulation, since with a shared slab probably nothing else will be possible)Prices are way too high — even if you don’t do any work yourself. In EL (material only), I paid 1200 euros for 10 cm (5 inches) perimeter insulation on the exterior basement walls. For the screed insulation with PUR (the most expensive insulation), it will also be around 1200 euros.
Just as a reference point — even with paid labor and some profit margin, those prices would be very ambitious.
But of course, it’s good to include a buffer in the calculations.
Hello Sebastian,
thanks for the assessment – that’s encouraging!
I can also well imagine installing the perimeter insulation myself. However, I’m not sure if the builder will agree to that. After all, I would probably need two or three days for it. During that time, no work could be done on the exterior.
Also, I have concerns regarding the warranty. I don’t want a situation later on where, in case of water ingress, they say we did something ourselves on the exterior basement wall.
Are there any indications whether it could cause problems to insulate only one of the basement rooms with screed insulation and insulate the others just on the walls?
Best regards
Ricardo
thanks for the assessment – that’s encouraging!
I can also well imagine installing the perimeter insulation myself. However, I’m not sure if the builder will agree to that. After all, I would probably need two or three days for it. During that time, no work could be done on the exterior.
Also, I have concerns regarding the warranty. I don’t want a situation later on where, in case of water ingress, they say we did something ourselves on the exterior basement wall.
Are there any indications whether it could cause problems to insulate only one of the basement rooms with screed insulation and insulate the others just on the walls?
Best regards
Ricardo
S
Sebastian798 Dec 2015 09:14You can install the perimeter insulation with two people in one day—quite comfortably. There can be no leaks since you only place the panels against the foundation or secure them with bitumen. That’s why we did it that way, but the building waterproofing including the cove detail was done by the structural contractor beforehand.
Therefore, I don’t see any warranty issues here for now...
I would insulate all rooms with screed insulation—it is possible. There is no frost at depth, but you always have edge areas that are cooler and extend into the room with the insulation.
Therefore, I don’t see any warranty issues here for now...
I would insulate all rooms with screed insulation—it is possible. There is no frost at depth, but you always have edge areas that are cooler and extend into the room with the insulation.
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