Hi, I?ve found the attached figure showing ?potential impact/benefit? of
energy modeling and ?degree of effort? along the different stages of
design in various publications, an in none of them it was properly
explained.

Maybe someone can help me understand the following:

1. Why are there local maximums of ?impact/benefits? at the end
of the ?Construction Documents? and ?Construction management? faze?
2. Why does degree of effort decreases during ?Construction
documents? and ?construction management?
3. Units at vertical axis? What are they measuring? ?Degree of
effort?, meaning time and $$; ?potential impact/benefit? meaning %of
energy saving?

I?ve tracked down this figure to this two ASHRAE publication, still seems
not to be the ?developing? source.

ASHRAE Journal September 2004, ?Integrated design for sustainable buildings?

ASHRAE Green Guide, Second Edition. Page 73, chapter 5.:

?Figure 5-1 conceptually shows the impact of providing design input at
succeeding

stages of a project relative to the cost and effort required. The solid
curve shows

that it is much easier to have a major impact on the performance (potential
energy savings, water efficiency, maintenance costs, etc.) of a building if
you start at the very

earliest stages of the design process; the available impacts diminish
thereafter as you

proceed through the subsequent design and construction phases. A corollary
to this

is that the cost of implementing changes to improve building performance
rises at

each successive stage of the project (cost is shown as the dotted curve of
this graph).?

Thanks!

Regads,

Santiago.