Hello everyone,
Not necessarily a construction topic, but I hope you experts will still share your expertise and experience 🙂
We are currently looking for a house and have found a very interesting offer: a barn built in 1960, converted into a residential home in 2013 (230m² (2,476 sq ft) living space, 380m² (4,090 sq ft) total usable space, which the energy report is based on). Energy consumption was about 18,000 kWh over the last 3 years, likely due to the well-insulated roof.
What we currently find hard to assess:
The walls are made of (natural) sandstone and are not insulated on the outside (only plastered). About 40cm (16 inches) thick.
Thermally, sandstone is said not to be ideal.
a) Are there any other disadvantages you see that I should be aware of?
b) Is it possible to insulate sandstone walls effectively? What would the approximate cost be for a floor plan of 12 x 12 meters (39 x 39 feet), then 5 meters (16 feet) straight up, plus an additional 7 meters (23 feet) sloping to the roof peak (triangular shape)?
c) For you, is this a deal breaker if someone wants to keep running costs fairly manageable, or could this be a good bargain if the house is otherwise attractive?
Looking forward to your input!
Not necessarily a construction topic, but I hope you experts will still share your expertise and experience 🙂
We are currently looking for a house and have found a very interesting offer: a barn built in 1960, converted into a residential home in 2013 (230m² (2,476 sq ft) living space, 380m² (4,090 sq ft) total usable space, which the energy report is based on). Energy consumption was about 18,000 kWh over the last 3 years, likely due to the well-insulated roof.
What we currently find hard to assess:
The walls are made of (natural) sandstone and are not insulated on the outside (only plastered). About 40cm (16 inches) thick.
Thermally, sandstone is said not to be ideal.
a) Are there any other disadvantages you see that I should be aware of?
b) Is it possible to insulate sandstone walls effectively? What would the approximate cost be for a floor plan of 12 x 12 meters (39 x 39 feet), then 5 meters (16 feet) straight up, plus an additional 7 meters (23 feet) sloping to the roof peak (triangular shape)?
c) For you, is this a deal breaker if someone wants to keep running costs fairly manageable, or could this be a good bargain if the house is otherwise attractive?
Looking forward to your input!
Newbi23 schrieb:
Offer for a barn built in 1960, converted into a residential house in 2013 (230m² (2,475 sq ft) living area, 380m² (4,090 sq ft) usable area on which the energy certificate is based). Consumption in the last 3 years was around 18,000 kWh, probably that low mainly due to the well-insulated roof. 18,000 kWh of what? Gas?
How many square meters are actually heated? Even with 230m² (2,475 sq ft) living area (multiplied by 1.2 equals energy reference area in the energy certificate), that would correspond to a final energy demand of 65 kWh/m² (21,000 BTU/sq ft). That’s quite low, even with a good roof. If the conversion to residential use was done in 2013, the Energy Saving Ordinance 2009 or 2013 (depending on the date of the conversion or building permit application) set minimum requirements for the energy performance of the building envelope.
A solid brick wall about 40 cm (16 inches) thick would not have met those standards. Is it a listed building? If yes, that could be the reason the wall was left as is – but also a reason why it should not be insulated from the outside now.
i_b_n_a_n schrieb:
I assume the planned building is in a rural or outlying area? (Barns usually are.)
Different rules apply there (building authority!), so you should definitely check in advance what is allowed. Regarding the installation of external thermal insulation composite systems (ETICS) or the placement of outdoor heat pump units, the location in a rural or outlying area does not make a difference. Both are permitted as long as property boundaries, setbacks, and noise limits (for heat pumps) are observed.
Newbi23 schrieb:
The sandstone is only visible inside on one wall; the rest is covered (white inside, yellow outside). Is the sandstone visible and unplastered inside? And outside as well?
Visible raw masonry of an external wall inside usually causes drafts.
In general, with visible sandstone without external plaster, if insulation is done at all, I would recommend internal insulation. But first, clarify the other issues.
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