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                                                                    EXHIBIT 10.4

                         ALTERRA HEALTHCARE CORPORATION
                             10000 INNOVATION DRIVE
                           MILWAUKEE, WISCONSIN 53226

                       AMENDMENT NO. 8 TO CREDIT AGREEMENT


                                                           As of August 31, 2000



Firstar Bank, National Association
777 East Wisconsin Avenue
Milwaukee, Wisconsin 53202

Ladies and Gentlemen:

                  Alterra Healthcare Corporation, a Delaware corporation (the
"Borrower"), hereby agrees with you as follows:

                  1. Definitions. Reference is made to that certain Revolving
Credit Agreement dated as of August 19, 1997, as amended through Amendment No. 7
thereto dated July 31, 2000 (the "Credit Agreement") between the Borrower and
you (the "Bank"), pursuant to which the Borrower has issued its Note dated June
30, 2000 (the "Original Note"). All capitalized terms used and not otherwise
defined herein shall have the meanings given to such terms by the Credit
Agreement as amended hereby.

                  2. Background. The Borrower has requested that the outstanding
loans under the Credit Agreement be converted to (i) a revolving credit facility
of up to $5,000,000, and (ii) a term loan in the principal amount of $4,885,000,
each maturing on August 31, 2001. The Bank has agreed to such conversion subject
to all of the terms and conditions of this Agreement. Any additional loans made
pursuant to the Credit Agreement, as amended hereby, together with the unpaid
balance of the Original Note, shall be evidenced by two new promissory notes of
the Borrower in the forms of Exhibit A (the "Revolver Note") and Exhibit B (the
"Term Note", and collectively with the Revolver Note, the "New Notes"), both to
be dated as of the date hereof. The Revolver Note and Term Note shall be in the
principal amounts of $5,000,000 and $4,885,000 respectively. Each of the New
Notes shall be executed by the Borrower and delivered to the Bank against the
return of the Original Note to the Borrower. Accrued interest, if any, on the
Original Note outstanding on the date of issuance of the New Notes shall be
included in interest due on the Revolver Note on the first interest payment date
specified therein or in the Credit Agreement, as amended hereby.
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                  3. Amendments to Credit Agreement. Subject to all of the terms
and conditions hereof, upon execution and delivery of this Agreement, the Credit
Agreement shall be amended, effective as of the date hereof, as follows:

                  (a) All references to the Credit Agreement in the Credit
         Agreement, the Note and all other documents related thereto shall refer
         to the Credit Agreement as amended hereby.

                  (b) All references in the Credit Agreement to the Note issued
         thereunder and the loans evidenced thereby shall refer collectively to
         the New Notes issued hereunder and the loans evidenced thereby
         (including the unpaid balance of the Original Note).

                  (c) Section 1.1 of the Credit Agreement is hereby amended and
         restated in its entirety to read as follows:

                           (a) REVOLVING CREDIT LOANS. From time to time prior
                  to August 31, 2001 or the earlier termination hereof (the
                  "Maturity Date"), the Borrower may borrow from the Bank for
                  working capital and general corporate purposes up to the
                  aggregate principal amount outstanding at any one time of the
                  lesser of (i) $5,000,000 (the "Revolver Loan Amount") or (ii)
                  if applicable, the Borrowing Base (defined below). All
                  revolving loans hereunder will be evidenced by a single
                  promissory note of the Borrower payable to the order of the
                  Bank in the principal amount of the Revolver Loan Amount (the
                  "Revolver Note"). Although the Revolver Note will be expressed
                  to be payable in the full Revolver Loan Amount, the Borrower
                  will be obligated to pay only the amounts actually disbursed
                  hereunder, together with accrued interest on the outstanding
                  balance at the rates and on the dates specified therein and
                  such other charges provided for herein. In the event that the
                  principal amount outstanding under the Revolver Note exceeds
                  the Borrowing Base at any time, the Borrower will immediately,
                  without request, prepay an amount sufficient to eliminate such
                  excess.

                           (b) TERM LOAN. On a date to be agreed upon between
                  the Borrower and Bank, the Borrower may obtain a term loan
                  from the Bank (the "Term Loan"), in the principal amount of
                  $4,885,000 (the "Term Loan Amount", and collectively with the
                  Revolver Loan Amount, sometimes called the "Aggregate Loan
                  Amount"). Repayments of the Term Loan may not be reborrowed
                  hereunder. The Term Loan shall be evidenced by a single
                  promissory note, payable to the order of the Bank in a
                  principal amount equal to the Term Loan Amount (the "Term
                  Note", and collectively with the Revolver Note, sometimes
                  called the "Notes").

                  (d) The date of July 31, 2000 set forth in Section 2(d) of
         Appendix 1 to the Credit Agreement is hereby amended to August 31,
         2000.
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                  (e) Each mortgage or other security instrument encumbering the
         real properties and given as security for the New Notes and certain
         other indebtedness of Borrower to the Bank shall be released in
         connection with the sale of any such properties, provided that the net
         proceeds of such sale are paid to the Bank and applied as provided in
         such mortgage or other security instrument (but regardless of whether
         all indebtedness secured thereby has been paid in full).

                  (f) The second sentence of Section 2.4 of the Credit Agreement
         is hereby amended to read as follows:

                  The Borrower will not, without the prior written consent of
                  the Bank, redeem, purchase or retire any of its capital stock
                  (other than (i) the Borrower exchanging capital stock of the
                  Borrower or rights to acquire capital stock of the Borrower
                  ("Stock Rights") for other capital stock of the Borrower or
                  Stock Rights; and (ii) the redemption of Stock Rights issued
                  pursuant to the Borrower's stockholder rights plan ("poison
                  pill"), as amended from time to time, pursuant to such plan,
                  provided that such redemption payments do not exceed, in the
                  aggregate $250,000) or pay dividends or make other payments or
                  distributions of a similar nature (other than (i) the dividend
                  or distribution of shares of capital stock of the Borrower or
                  of Stock Rights or (ii) pay-in-kind dividends payable in
                  connection with the proposed equity transaction referred to in
                  Section 4.1(i) below).

                  4. Acknowledgement of Cross-Default. Bank hereby acknowledges
and agrees that a default under that certain Promissory Note dated September 30,
1999 executed by Borrower in favor of Manor Care of America, Inc. in the
original principal sum of $3 million (the "Manor Care Note") shall not
constitute a default hereunder provided that (i) adequate reserves therefore are
maintained on Borrower's financial statements and (ii) the Manor Care Note is
paid in the amount and at the time Alterra's liability, if any, thereunder is
finally resolved.

                  5. Conditions. Notwithstanding any other provision of this
Agreement, this Agreement shall not become effective unless and until it has
been signed by all parties to the Credit Agreement.

                  6. Representations and Warranties. The Borrower hereby repeats
and reaffirms the representations and warranties set forth in Article II of the
Credit Agreement. The Borrower also represents and warrants that the execution,
delivery and performance of this Agreement and the other documents required
hereby are within the corporate powers of the Borrower, have been duly
authorized by all necessary corporate action and do not and will not (i) require
any consent or approval of the stockholders of the Borrower; (ii) violate any
provision of the articles of incorporation or by-laws of the Borrower or of any
law, rule, regulation, order, writ, judgment, injunction, decree, determination
or award presently in effect having applicability to the Borrower or any
subsidiary; (iii) require the consent or approval of, or filing or registration
with, any governmental body, agency or authority; or (iv)

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result in any breach of or constitute a default under, or result in the
imposition of any lien, charge or encumbrance upon any property of the Borrower
or any subsidiary pursuant to, any indenture or other agreement or instrument
under which the Borrower or any subsidiary is a party or by which it or its
properties may be bound or affected. This Agreement constitutes, and each of the
documents required herein when executed and delivered hereunder will constitute,
legal, valid and binding obligations of the Borrower or other signatory
enforceable in accordance with its terms, except as such enforceability may be
limited by bankruptcy or similar laws affecting the enforceability of creditors'
rights generally.

                  7. Confirmation of Agreements. Except as expressly provided
above, the Credit Agreement shall remain in full force and effect. This
Agreement does not constitute a waiver or Agreement of any term, condition or
covenant in the Credit Agreement other than as specifically set forth above.
Nothing contained in this Agreement or in any other document, or any course of
dealing with the Borrower, shall be construed to imply that there is any
agreement by the Bank to provide any waiver or agree to any Agreement in the
future. This Agreement shall not release, discharge or satisfy any present or
future debts, obligations or liabilities to the Bank of the Borrower or of any
debtor, guarantor or other person or entity liable for payment or performance of
any of such debts, obligations or liabilities of the Borrower, or any mortgage,
security interest, lien or other collateral or security for any of such debts,
obligations or liabilities of the Borrower or such debtors, guarantors or other
persons or entities, or waive any default except as expressly provided herein,
and the Bank expressly reserves all of its rights and remedies with respect to
the Borrower and all such debtors, guarantors or other persons or entities, and
all such mortgages, security interests, liens and other collateral and security.
This is an amendment and not a novation. The Borrower acknowledges and agrees
that the obligations under the Credit Agreement, as amended hereby, and New
Notes exist and are owing with no offset, defense or counterclaim assertible by
the Borrower and that the Credit Agreement, as amended hereby, and the New Notes
are valid, binding and fully enforceable according to their respective terms.

                  8. Miscellaneous. The Borrower shall be responsible for the
payment of all fees and out-of-pocket disbursements incurred by the Bank in
connection with the preparation, execution, delivery, administration and
enforcement of this Agreement including all costs of collection, and including
without limitation the reasonable fees and disbursements of counsel for the
Bank, whether or not any transaction contemplated by this Agreement is
consummated. The provisions of this Agreement shall inure to the benefit of any
holder of the New Notes, and shall inure to the benefit of and be binding upon
any successor to any of the parties hereto. All agreements, representations and
warranties made herein shall survive the execution of this Agreement and the
making of the loans under the Credit Agreement, as so amended. This Agreement
shall be governed by and construed in accordance with the internal laws of the
State of Wisconsin. This Agreement may be signed in any number of counterparts
with the same effect as if the signatures thereto and hereto were upon the same
instrument. This Agreement is solely for the benefit of the parties hereto and
their permitted successors and assigns. No other person or entity shall have any
rights under, or because of the existence of, this Agreement.
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                  If the foregoing is satisfactory to you, please sign the form
of acceptance below and return a signed counterpart hereof to the Borrower.

                                Very truly yours,

                                ALTERRA HEALTHCARE CORPORATION

(Corporate Seal)

                                By:          /s/ Mark W. Ohlendorf
                                    --------------------------------------------
                                    Title: Mark W. Ohlendorf, Sr. Vice President
                                    and Chief Financial Officer



                  Agreed to as of the date first above written.

                                FIRSTAR BANK, NATIONAL
                                   ASSOCIATION



                                By:          /s/ Dale L. Welke
                                    -----------------------------------
                                    Title:   Vice President