Jason wrote:
Is there such a thing as too much attic insulation?

That depends. If you aren't concerned with cost, then no. However, since there
are diminishing returns, at some point, adding insulation beyond a certain point
is not cost effective. That point is dependent on what future energy costs are.

Does attic insulation really cut
down on heat gain in the summer and heat loss in the winter?

Yes.

Or is there
some other place to look to cut down on heat gain?

If the only insulation is in the attic, then all you are doing is losing
heat/cool through the walls and basement. As well, too much airflow through the
walls, doors, windows etc makes the attic insulation ineffective.

The optimum is to balance it all out. You have to ensure that you have
insulation in the walls and basement as well. Your windows and doors should not
leak air excessively. Ditto walls and such. If you restrict air flow too much,
you should then look at a heat recovery ventilator to ensure proper ventilation
of living space without heat/cool losses.

In general, retrofitting an older house to the max is very expensive and not
always worth the trouble. Sometimes something as simple as a few tubes of
acoustic caulking is very cost effective - close up the biggest air leaks. You
have to investigate all the options and decide when the cost exceeds the benefit.

Mike