Cohousing-L Mailing List: Re: Soundproofing [was marketing Aria Cohousing in Denver to families

[R Philip Dowds (rpdowds]

The cost of any building — large or small, wood or steel, etc — is the function 
of the sum of many different components.  Each component — like lighting, or 
windows, or floor finish, or a zoned heating system — can be luxury, moderate, 
or inexpensive (“cheap”).  Designers, builders and owners will make decisions 
about where they want to spend or save money, so it’s entirely common to find 
construction that has (for instance) an “expensive” security system combined 
with “cheap” plumbing work.

In summary, the hypothetical concrete floors were not economically unfeasible, 
they were just de-prioritized relative to other wants, needs and features.  The 
reason why you are more likely to find steel and concrete in larger residential 
buildings is that more substantial construction is mandated by law for the 
building type and size, in order to minimize the spread of fire between 
dwelling units.

Thanks,
Philip Dowds
Cornerstone Village Cohousing
Cambridge, MA

> On Oct 2, 2016, at 9:21 PM, Bob Morrison via Cohousing-L <cohousing-l [at] 
> cohousing.org> wrote:
> 
>  Thank you Beverly for starting this discussion about soundproofing between 
> stacked units. Here at Mosaic Commons we have two pairs of stacked units, all 
> 1-br. Both pairs are in triplex buildings in which the third unit is a large 
> townhouse. 
>  The subfloor of the upstairs units is wood, without a skim coat of gypcrete. 
> When I was looking into buying a unit, I asked why the stacked units don't 
> have concrete floors. They said a concrete floor is economically unfeasible 
> for this small a building because the chase thru the floor to run plumbing, 
> wiring, etc. to the second floor would be too expensive. In a larger 
> building, you can spread out the cost of the chase over more units, so it 
> becomes economically feasible. Therefore, concrete floors between stacked 
> units are common in larger buildings. 
> 
> Bob Morrison
> Mosaic Commons Cohousing
> Berlin, MA