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                                                                    EXHIBIT 4.12



October 8, 2004

Re: Amended Secondment

Mr. James Chilcoff
Rosehill, Australia

Dear Jamie:

Congratulations on your promotion to Executive Vice President - International.
With this promotion, we offer you an Amended Secondment ("Agreement").

In light of the fact that you are now a member of the Group Management Team
("GMT"), James Hardie would like to amend your Secondment Agreement dated June
2, 2003 ("Secondment"), in consideration of the covenants contained herein, by
providing you the terms set forth below.

For the purposes of this Agreement, the word "Company" collectively means James
Hardie Building Products, Inc. ("JHBP") and James Hardie Building Products Pty
Ltd, known as James Hardie Australia ("JHA"). In other words, JHBP and JHA are
collectively referred to herein as "Company".

It is understood by you and the Company that this Agreement shall terminate and
supersede all prior employment agreements, service agreements, or other
agreements, promises and representations regarding the terms and conditions of
your employment between you and the Company or any of its subsidiaries or
affiliates, including but not limited to the Secondment, which is no longer of
any force or effect.

It is further understood by you and the Company that the terms and conditions of
your employment are otherwise governed by the policies and procedures of JHBP
applicable to similarly-situated executives of JHBP when you are working in the
United States, and by the policies and procedures of JHA applicable to
similarly-situated executives of JHA when you are working on assignment for JHA
in Australia.

It is a condition of the Agreement that you are granted a work permit for the
duration or your work assignment in Australia.

                            WORK FOR JHA IN AUSTRALIA

LOCATION OF SERVICE

1.01  The position is presently located at our Rosehill Office. The location of
      your employment may be changed from time to time in accordance with the
      Company's business needs. In the event of this occurring any such change
      and the Company's relocation policy would first be discussed with you.

REPORTING RELATIONSHIP

2.01  You will report to Louis Gries, EVP Operations.

REMUNERATION

3.01       Your remuneration will be based on an annual salary of US$250,000.

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3.02  On the basis that you will be living away from your usual place of
      residence, you will receive an additional taxable expatriate allowance of
      US$20,000 per year.

3.03  Your total remuneration will be paid to you through your current USA
      payroll.

3.04  By remaining on the USA payroll, you will continue to be eligible to
      participate in the USA 401(k) plan, according to Company and plan
      policies. The Company currently matches your contribution $1 for $1 up to
      six percent of your salary up to the IRS maximum.

3.05  Salaries are reviewed on the basis of measured performance in July of each
      year, starting July 2005.

3.06  Your remuneration relies on the fact that you are living away from home
      and therefore you will be required to sign a declaration to that effect
      annually (see attached), which the Company will retain with its records.

PERFORMANCE BONUS

4.01  Your target bonus for FY 05 will be 45% of your March 31, 2005 base salary
      for April 1, 2004 to August 15, 2004 and 55% of your March 31, 2005 base
      salary starting August 15, 2004. Your actual bonus will be calculated
      based on JH's EP bonus plan parameters and your achievements against
      agreed objectives and targets (IP). Your bonus will be split between EP
      results (80%) and Individual Performance (20%).

4.02  The terms and conditions surrounding the plan are subject to alteration at
      the discretion of the Company and participation is reviewed annually.

SHARE PLAN

5.01  You will be eligible to participate in the JHI NV Equity Incentive Plan
      and continue to be treated as a U.S. employee for this consideration. The
      decision on equity eligibility and amounts is made each year. For purposes
      of that decision, you will be treated as a US employee.

TAXATION ADVICE

6.01  The Company will provide a tax adviser through PWC to assist in the
      processing of tax returns and advice on tax matters associated with your
      employment in Australia.

LEAVE

7.01  Annual Leave You will continue to accrue annual leave under the U.S.
      vacation policy. Based on your tenure, you will accrue 3 weeks (120 hours)
      per annum. You may continue to accrue up to a maximum of 240 hours based
      on Company policies.

7.02  Home Leave JHBP will pay coach class return airfares to the USA for you
      and your family, twice per annum. These tickets may be exchanged for
      travel tickets elsewhere in the world but not for cash. They may also be
      used to fly family members to Australia to visit.

CAR

8.01  The Company will provide both you and your spouse with cars; the company
      will provide a car for your use consistent with the level of your current
      Company-provided vehicle, and provide a car equivalent to a Honda Accord
      or similar class car for your spouse's use. Auto insurance,

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      routine maintenance and warranties associated with the costs for
      maintenance of the cars will be paid by the Company. Business gasoline
      costs will be reimbursed per local policy; expenses for personal mileage
      will not be reimbursed.

POLICIES

9.01  Other policies applicable to you during your secondment will be as per the
      JHA policies.

                      CONDITIONS OF RELOCATION TO AUSTRALIA

IMMIGRATION

10.01 Your employment in Australia will be dependant on successfully maintaining
      the immigration status necessary for you to work in Australia.

10.02 If, at any stage, you intend to change your residency status from
      temporary to permanent, you are to advise the Company.

PERSONAL ACCIDENT INSURANCE

11.01 JHBP provides 24-hour business travel accident insurance for all
      expatriates, in accordance with the provisions of the applicable JHBP
      insurance plan or insurance agreement.

MEDICAL / HOSPITAL INSURANCE

12.01 As an expatriate employee, you have the same Life, Medical, Dental, Vision
      and Disability benefits as U.S. employees of JHBP. Since the PPO
      (Preferred Provider) Medical Plan has no specific contracted providers in
      your region, your medical benefits will be paid at the PPO level of
      benefits for services rendered outside of the U.S.

WHEN APPROPRIATE, REMOVAL AND STORAGE CHARGES

13.01 The cost of packing, freight and insurance in transit of your personal
      effects (excluding items of unique high value (e.g. pianos) or animals)
      will be met by JHA.

13.02 Items of value that are not shipped may be placed in commercial storage at
      the employee's home base. A reasonable cost of storage, removal into
      storage and insurance on storage items will be met by JHA.

ACCOMMODATION

14.01 LONG-TERM ACCOMMODATION
      To satisfy your long-term accommodation needs, JHA will continue to
      reimburse you AUD $3,500 per month to cover the cost of a fully furnished
      apartment or house, while you are working for JHA in Australia. It is also
      agreed that JHA will pay this amount regardless of whether less or more
      than this amount is actually incurred. Where the actual housing cost is
      less than A$3,500, the payment will be broken into two components:

      -     the payment/reimbursement of the actual rent; and

      -     the balance paid as a taxable cash allowance, in which the company
            will pay for the taxes.

EDUCATION FOR CHILDREN

15.01 JHA will continue to provide the costs associated with reasonable tuition
      and appropriate fees, which may apply for your school-aged children while
      you are working for JHA in Australia.

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LIABILITY FOR TAX PAYMENTS

16.01 You will continue to be tax equalized to the State of California for the
      period of your work assignment for JHA in Australia. Tax equalization is
      intended to equate the tax liability you incur during your overseas
      assignment with that of a domestic employee under similar economic
      circumstances. You will be reimbursed for any excess of U.S. or foreign
      taxes you are required to pay beyond the U.S. and California taxes you
      would have incurred on your base salary, bonus, if any, and imputed income
      from group life insurance, if you had not taken the overseas assignment.

16.02 While you are on assignment for JHA in Australia, you will pay a
      hypothetical tax in lieu of actual tax liabilities. The hypothetical tax
      is representative of your tax responsibilities while on assignment. We
      will have PricewaterhouseCoopers calculate the amount to be withheld.

                               GENERAL CONDITIONS

PERIOD OF NOTICE

17.01 Either party may terminate this Agreement by giving the other party thirty
      (30) days notice in writing. The Company may elect to make a payment in
      lieu of the whole or part of any period of notice given to the Company by
      you, or by the Company to you. Of course, the Company may terminate this
      Agreement immediately if it reasonably believes that you have engaged in
      conduct which violates Company policy, or otherwise constitutes dishonest
      activity, whether criminal or otherwise, including but not limited to
      fraud, misrepresentation, theft of Company property, embezzlement, larceny
      and misappropriation under applicable state and/or federal law.

TERMINATION OF JHA WORK ASSIGNMENT

18.01 In the event of termination of the JHA work assignment by JHA or you, JHA
      will pay reasonable repatriation costs for you, your family and your
      belongings to California, unless you were in breach of conditions applying
      to your employment. Repatriation would have to occur within six months of
      termination for this clause to apply.

18.02 Termination of employment by Redundancy, Resignation or other reason, will
      mean conclusion of the transfer and you will be assisted with relocation
      as described above, to California.

18.03 At the end of your JHA work assignment, JHBP will attempt to return you to
      a position in California in the US business and repatriate you to that
      location, unless you are released based on the Company's reasonable belief
      that you engaged in conduct which violates Company policy or otherwise
      constitutes dishonest activity, whether criminal or otherwise, including
      but not limited to fraud, misrepresentation, theft of Company property,
      embezzlement, larceny and misappropriation under applicable state and/or
      federal law. Refer to Repatriation Conditions section below.

CONFLICT OF INTEREST

19.01 You agree to declare any potential conflict of interest, which might
      affect the decisions of the Company in dealing with any third party, where
      either you or an associate or family member has an interest in that third
      party by way of employment or financial interest or any potential personal
      gain.

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CONFIDENTIALITY

20.01 In accepting this appointment, you agree that during or after your
      employment with the Company you will not disclose to anyone outside the
      Company, or use in any way other than in the Company's business, any
      information that may reasonably be said or understood to be confidential
      in relation to the Company's activities.

20.02 Further, you agree that on termination of employment you will give up and
      not take with you any material containing information, which may
      reasonably be understood to be confidential in relation to the Company's
      activities.

                             REPATRIATION CONDITIONS

REPATRIATION TO USA

21.01 Upon successful completion of your work assignment for JHA in Australia,
      JHA will pay reasonable repatriation costs for you and your family to
      return to California or location of JHBP assignment, including the return
      coach class airfare. JHA will also pay reasonable costs associated with
      the shipment of your belongings. In addition, JH will pay reasonable
      housing costs for a period of up to one (1) month upon return to
      California or location of JHBP assignment. You will also be provided with
      tax assistance in relation to your return to the USA.

21.02 JH will reimburse the costs associated with purchasing a house in the USA.
      The details of this will be addressed in a contract that moves you back to
      the U.S.

                            CONDITIONS OF EMPLOYMENT

POST-TERMINATION CONSULTING PERIOD

22.01 Upon the termination of your employment with JHBP, you agree to:

      (a)   Consult to JHBP for two years for up to 100 hours/year. You agree to
            do this, as well as to not violate any of the TRADE SECRET/
            RESTRCTIVE COVENANTS set forth in this Agreement or in its policies
            and procedures, in order to protect our Company's proprietary,
            confidential business and manufacturing information. In exchange for
            the payment of an amount equal to your annual base salary at the
            time of termination (paid in monthly installments), in accordance
            with the terms of a James Hardie Consulting Agreement, a format of
            which is attached as a copy, for your general consideration. The
            exact terms and conditions will be agreed upon when, and if, this
            Agreement is prepared for execution. The Company will prepare this
            Consulting Agreement, in final.

      (b)   Additionally, the Company may elect to extend the Consulting
            Agreement for an additional two years, and you will agree to such
            extension, in exchange for the amount equal to the annual base
            salary for each year of extension.

RESTRICTIVE COVENANTS

23.01 Trade Secrets. Confidential and Proprietary Business Information.

      (a)   The Company has advised you and you have acknowledged that it is the
            policy of the Company to maintain as secret and confidential all
            Protected Information (as defined below), and that Protected
            Information has been and will be developed at substantial cost and
            effort to the Company and other companies in the James Hardie group
            - these companies together with the Company are referred to in this
            Agreement as the "Group." "Protected Information" means trade
            secrets, confidential and proprietary

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                                                                               6

            business information of the Group, any information of the Group
            other than information which has entered the public domain (unless
            such information entered the public domain through effects of or on
            account of you), and all valuable and unique information and
            techniques acquired, developed or used by the Group relating to its
            business, operations, employees, customers and suppliers, which give
            the Group a competitive advantage over those who do not know the
            information and techniques and which are protected by the Group from
            unauthorized disclosure, including but not limited to, customer
            lists (including potential customers), sources of supply, processes,
            plans, materials, pricing information, internal memoranda, marketing
            plans, internal policies, and products and services which may be
            developed from time to time by the Group and any of their agents or
            employees.

      (b)   You acknowledge that you have acquired and will acquire Protected
            Information with respect to the Group and its successors in
            interest, which information is a valuable, special and unique asset
            of the Group's business and operations and that disclosure of such
            Protected Information would cause irreparable damage to the Group.

      (c)   Either during or after termination of employment by the Company, you
            shall not, directly or indirectly, divulge, furnish or make
            accessible to any person, firm, corporation, association or other
            entity (otherwise than as may be required in the regular course of
            your employment) nor use in any manner, any Protected Information,
            or cause any such information of the Group to enter the public
            domain.

23.02      Non-Competition

      (a)   You agree that you shall not during your employment with the
            Company, and, subject for a period of at least two (2) years, and up
            to four (4) years, at the Company's discretion (assuming it
            exercises its rights to have you engaged as a Consultant, as set
            forth above), after the termination of the Agreement, directly or
            indirectly, in any capacity, engage or participate in, or become
            employed by or render advisory or consulting or other services in
            connection with any Prohibited Business as defined in subsection
            (c).

      (b)   You agree that you shall not, during your employment with the
            Company, and, for a period of at least two (2) years, and up to four
            (4) years at the Company's discretion (assuming it exercises its
            rights to have you engaged as a Consultant, as set forth above),
            after the termination of this Agreement, make any financial
            investment, whether in the form of equity or debt, or own any
            interest, directly or indirectly, in any Prohibited Business.
            Nothing shall, however, restrict you from making any investment in
            any company whose stock is listed on a national securities exchange;
            provided that (i) such investment does not give you the right or
            ability to control or influence the policy decisions of any
            Prohibited Business, and (ii) such investment does not create a
            conflict of interest between your duties hereunder and your interest
            in such investment.

      (c)   "Prohibited Business" shall be defined as the business of:

            (i)   marketing or selling of fiber cement products, where the
                  marketing or selling of such products is a principal activity
                  of the business;

            (ii)  manufacturing or processing fiber cement products;

            (iii) building, assembling, operating or maintaining plant and
                  equipment, where that plant and equipment is particular to the
                  manufacturing or processing of fiber cement products;

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                                                                               7

            (iv)  manufacturing or processing raw materials for fiber cement
                  products where that manufacturing or processing is particular
                  to the raw material used in fiber cement products;

            (v)   research or development activities relating to
                  subsections(c)(i)-(iv); and

      any branch, office or operation thereof, which is a competitor of the
      Group or which has established or seeks to establish contact, in whatever
      form (including, but not limited to solicitation of sales, or the receipt
      or submission of bids), with any entity who is at any time a client,
      customer or supplier of the Group (including but not limited to all
      subdivisions of the federal government).

23.03 Non-Solicitation. From the date hereof until at least two (2) years, and
      up to four (4) years at the Company's discretion, after your termination
      of employment with the Company, you shall not, directly or indirectly (a)
      encourage any employee or supplier of the Group or any of their successors
      in interest to leave his or her employment with the Group or any of their
      successors in interest, (b) employ, hire, solicit or cause to be employed,
      hired or solicited (other than by the Group or any of their successors in
      interest), or encourage others to employ or hire any person who within at
      least two (2) years, and up to four (4) years at the Company's discretion,
      prior thereto was employed by the Group or any of their successors in
      interest, or (c) establish a business with, or encourage others to
      establish a business with, any person who within at least two (2) years,
      and up to four (4) years at the Company's discretion, prior thereto was an
      employee or supplier of the Group or any of their successors in interest.

23.04 Disclosure of Employee-Created Trade Secrets Confidential and Proprietary
      Business Information. You agree to promptly disclose to the Company all
      Protected Information developed in whole or in part by you during your
      employment with the Company and which relates to the Group's business.
      Such Protected Information is, and shall remain, the exclusive property of
      the Company. All writings created during your employment with the Company
      (excluding writings unrelated to the Company's business) are considered to
      be "works-for-hire" for the benefit of the Group and the Company shall own
      all rights in such writings.

23.05 Survival of Undertakings and Injunctive Relief

      (a)   The provisions of these RESTRICTIVE COVENANTS of this Agreement
            shall survive both the termination of your employment with the
            Company and the termination of the Agreement, irrespective of the
            reasons for such termination.

      (b)   You acknowledge and agree that these RESTRICTIVE COVENANTS imposed
            upon you by this Agreement and the purpose of such restrictions are
            reasonable and are designed to protect the Protected Information and
            the continued success of the Company without unduly restricting your
            future employment by others. Furthermore, you acknowledge that, in
            view of the Protected Information which you have or will acquire or
            have or will have access to and in view of the necessity of these
            restrictions, any violation of them would cause irreparable injury
            to the Company and its successors in interest, with respect to the
            resulting disruption in their operations. By reason of the foregoing
            you consent and agree that if you violate any of these restrictions,
            or RESTRICTIVE COVENANTS, the Company and its successors in interest
            as the case may be, shall be entitled, in addition to any other
            remedies that they may have, including money damages, to an
            injunction to be issued by a court of competent jurisdiction,
            restraining you from committing or continuing any violation of such
            Sections of this Amendment.

            In the event of any such violations of these RESTRICTIVE COVENANTS,
            you further agree that the time periods set forth in such Sections
            shall be extended by the period

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                                                                               8

            of such violation, and you consent to the jurisdiction of the
            Superior Court for the County of Orange, State of California, as the
            competent court to hear and to determine any action in equity or law
            filed by the Company against you with respect to its necessity to
            protect itself under these RESTRCITIVE COVENANTS.

TERMINATION

24.01 Termination of Employment by Voluntary Resignation /Death /Disability.

      (a)   Your employment under the Agreement may be terminated:

            (i)   Upon your voluntary resignation in accordance with the
                  notification requirement provided in the Agreement;

            (ii)  Upon your death, the Agreement, and your employment hereunder
                  shall terminate immediately and without notice by the Company;
                  or

            (iii) In the event of your inability to perform your duties or
                  responsibilities thereunder, as a result of a Permanent
                  Disability (as defined below) upon written notice by the
                  Company. A "Permanent Disability" occurs when for a period of
                  ninety (90) consecutive calendar days, or an aggregate of one
                  hundred twenty (120) calendar days during any calendar year
                  (whether or not consecutive) you are unable to perform your
                  duties or responsibilities hereunder as a result of a mental
                  or physical ailment or incapacity. Upon the occurrence of a
                  Permanent Disability, the Company will evaluate your condition
                  and determine whether or not to send written notice of your
                  termination.

      (b)   Upon a voluntary resignation, you shall not be entitled to payment
            of any compensation other than salary under the Agreement, as
            amended, earned up to the date of such resignation, any accrued but
            unpaid vacation days, and any stock options, warrants or similar
            rights which have vested at the date of such resignation. The
            Company, in its sole and absolute discretion, may decide to continue
            to pay you your Annual Base Salary, for up to two (2) years after
            your voluntary resignation, in return for you not violating the
            RESTRICTIVE COVENANTS and/or provisions therein, for an equivalent
            period.

      (c)   Upon your death, the Company shall pay or grant, to such person as
            you designate in a notice filed with the Company, or, if no such
            person shall be designated, to your estate as a lump sum death
            benefit, an amount equal to any compensation under the Agreement, as
            amended, earned up to the date of your death, including salary and
            any accrued but unpaid vacation days. In addition, any stock options
            or warrants which have vested at the time of your death will be
            exercisable by your estate in accordance with the Company's Equity
            Incentive Plan. Your designated beneficiary or the executor of your
            estate, as the case may be, shall accept the payment provided for in
            this section, in full discharge and release of the Company of and
            from any further obligations under the Agreement, as amended.

      (d)   Upon your permanent disability, you shall be entitled to the benefit
            of disability or other relevant insurance or benefits provided. You
            shall not be entitled to payment of any compensation other than
            salary under the Agreement, as amended, earned up to the date of
            such permanent disability, any accrued but unpaid vacation days, and
            any stock options, warrants or similar rights which have vested at
            the date of such termination. The Company, in its sole and absolute
            discretion, may decide to continue to pay you your Annual Base
            Salary, for up to two (2) years after your voluntary resignation, in
            return for you not violating the RESTRICTIVE COVENANTS

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                                                                               9

            for an equivalent period and your execution, without revocation, of
            a Company Release of Claims upon the effective date of the
            termination of your employment.

24.02 Termination for Cause.

      (a)   The Company may terminate your employment for Cause by giving you
            written notice of such termination. For purposes of the Agreement,
            as amended, "Cause" for termination shall mean:

            (i)   the willful failure or refusal to carry out the reasonable
                  directions of the Chief Executive Officer or Board of
                  Directors, which directions are consistent with your duties as
                  set forth under the Agreement;

            (ii)  a willful act by you that constitutes gross negligence in the
                  performance of your duties under the Agreement, as amended,
                  and which materially injures the Company. No act, or failure
                  to act, by you shall be considered "willful" unless committed
                  without good faith and without a reasonable belief that the
                  act or omission was in the Company's best interest; or

            (iii) a conviction for a violation of a state or federal criminal
                  law involving the commission of a felony or other crime
                  involving moral turpitude.

      (b)   Upon termination for Cause, you shall not be entitled to payment of
            any compensation other than salary under the Agreement earned up to
            the date of such termination, any accrued but unpaid vacation days,
            and any stock options, warrants or similar rights which have vested
            at the date of such termination. The Company, in its sole and
            absolute discretion, may decide to continue to pay you your Annual
            Base Salary, for up to two (2) years after such termination for
            Cause, in return for you not violating the RESTRICTIVE COVENANTS for
            an equivalent period and your execution, without revocation, of a
            Company Release of Claims upon the effective date of the termination
            of your employment.

24.03 Termination Without Cause. Should your employment be terminated for a
      reason other than as specifically set forth above:

      (a)   You shall be paid the salary earned up to the date of such
            termination under the Agreement any accrued but unpaid vacation
            days, and any stock options, warrants or similar rights which have
            vested at the date of such termination.

      (b)   In addition, the Company, in its sole and absolute discretion, may
            decide to continue to pay you additional amounts (in monthly
            installments) equal to your Annual Base Salary as of the date of
            termination of employment in accordance with the Company's normal
            practices for other senior executives, for up to two (2) years
            following your termination, in return for you not violating the
            provisions of the RESTRICTIVE COVENANTS above, for an equivalent
            period and your execution, without revocation, of a Company Release
            of Claims at that time.

      (c)   All of the stock options, warrants, retirement benefits and other
            similar rights, if any, granted by the Company to you that are
            vested at the date of the termination of your employment, shall
            remain vested. All stock options that will vest between the date of
            such termination of employment and the completion of the Consulting
            Agreement will continue to vest on the vest dates stipulated in the
            grant document(s). All stock options unvested as of the completion
            of the Consulting Agreement will immediately expire. All stock
            options vested as of the completion of the Consulting Agreement will
            remain exercisable until the earlier of (i) the date such Stock
            Options would expire in accordance with their terms, and (ii) 90
            days after the date of completion of the

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            Consulting Agreement, unless terminated earlier per the terms of the
            Consulting Agreement.

24.04 No Mitigation. You shall not be required to mitigate the amount of any
      payment provided for in the Termination without Cause Section, above, by
      seeking other employment or otherwise, nor shall the amount of any payment
      provided for under this section be reduced by any compensation earned by
      you, as a result of employment by another company, self-employment or
      otherwise.

In acknowledgment of your agreement to the terms and conditions of this
Agreement, please sign and return to Cathy McCutcheon, in Mission Viejo HR, the
duplicate copy of this letter.

JAMES HARDIE BUILDING PRODUCTS, INC.,
A California corporation

By: /s/ Louis Gries                       Oct 13, 2004
------------------------------            -------------
Louis Gries                               date
Executive VP Operations

James Chilcoff, an individual

/s/ James Chilcoff                        Oct 19, 2004
------------------------------            ------------
James Chilcoff                            date