Tracking multiple sales taxes

[Ian Haycox]

I'm using GNUCash to record my expenses for a house renovation and would like to
keep track of the sales tax spent for each of the renovation items. In
France there are
two different rates of sales tax (TVA), 19.6% and 5.5%  Recording
sales tax has an effect
on the capital gains due at resale.

My account structure looks like:

Expenses
    Renovation
        TVA 19.6
        TVA 5.5
        Contractors
        Materials
        Tools and equipment
        Garden
        Consumables
            ....

I then record a transaction by withdrawing from my checking account
and splitting the deposit
between an appropriate TVA expense account and the actual expense (e.g. Garden).

The problem is I cannot see how much I have spent on, for example, the
garden because
the account only shows the amount less tax and there may be  entries
for the different
tax rates, so I can't just multiple the amount by 19.6%. Each txn may
have different
TVA amounts for the same expense account.

Is there a way to report the totals including tax for each expense or
change the account
structure so I can see the total spent on each expense item.

Thanks.