Re: Cost Apportionment of Infrastructure
From: Ian Higginbottom (
Date: Tue, 15 Nov 94 18:22 CST
Ray Gasser wrote regarding apportionment of infrastructure costs
>We'd love to hear from anyone with ANY thoughts on the matter, since
>we're gonna be going at it this weekend.

Cascade Cohousing takled this one a couple of years ago.  It was the hardest
decission of the project and it tested our structure and process to the
limit.  We used a preferential vote over a number of options.  We were
hurting for 4 months afer the decision because of some bad feeling over the
process and the result.  On the other hand we MADE a very difficult
decission and are now at ease with our solution.

You are talking money and personal self interest cannot easility be put
aside for the good of the group so you are on difficult ground,
GOODLUCK and most importantly GOOG HUMOUR.

Some ideas from our decission (I posted some stuff on this once before so it
should be on the archives).

We had multiple objectives in setting what we called our common costs share
for each unit (ie infrastructure costs) and multiple points of view.  We
wanted to encourage small houses(to reduce gross use of rescources),
encourage families, not discourage small households, to have an essentially
user pays approach (ie not obviously subsidise each other), to be fair and
some other things.  We analysed the infrastructure to see
what its costs were dependant on.  For example the council require 1.5 car
parks per 80 square meters of house ir directly proportional to house size.
Roads and pedestrian paths are not related to house, so their is some
arguement to divide them equally, or per person.  leagal cost (which we
lumped in here) are largely independent of numbers.  The more people in the
group the bigger the common house is likely to be.  The bigger the house the
more common land it takes up.  So after looking at all these factors and our
broader objectives we had only one person in the group who wanted a flat
division across all households.  The finance commitee then looked at a
number of ways of dividing the costs, we looker at 40% flat 60%by area and
other such combinations.  We ended up with a logarithmic relationship, some
thing like 25% flat and 75% divided up in proportion to the log (base 10) of
house size (meters squared) minus 40.  This works so long as no one has a
house smaller than about 60 square meters.

This curve meant that the bigger your house the more you paid, but that as
you kept getting bigger the less you paid per extra square meter.  We then
added a lookup table with house size and the amount you pay to our legal
agreement and most members didn't have to worry about the math, just look up
what they had to pay.  You need to plot up the curve to see what it means
for different size houses.

This solution works for us.
I think my main ponit though is not to underestimate the strength of feeling
in debating this issue.

I hope it goes smoothly for you.

Ian Higginbottom
Cascade Cohousing

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