BUILD TO SUIT OPTION AGREEMENT

THIS BUILD TO SUIT OPTION AGREEMENT ("Agreement") is made and entered into as of this 25th day of October, 1996, by and between MARTIN/CAMPUS ASSOCIATES, L. P., a Delaware limited partnership ("Owner"), and AT HOME CORPORATION, a Delaware corporation ("At Home").

RECITALS

This Agreement is made and entered into with reference to and upon the basis of the following facts, intentions and understandings of the parties:

A. Owner is the owner of

(a) that certain real property situated in the City of Red wood City, County of San Mateo, State of California, which is described on Exhibit A hereto (the "North Expansion Parcel"); provided, however, that Owner holds an unconditional option to purchase, but does not own, the so-called "Sears Parcel," as further described on Exhibit A-1 hereto (the "Sears Parcel"); and

(b) that certain unimproved real property situated in the City of Redwood City, County of San Mateo, State of California, which is described on Exhibit B hereto (the "South Expansion Parcel"). The North Expansion Parcel and the South Expansion Parcel shall be hereinafter from time to time collectively referred to as the "Property".

B. Owner and At Home have entered into that certain Lease dated as of October 18, 1996 (the "Broadway Lease") pursuant to which Owner is leasing to At Home, and At Home is leasing from Owner, that certain real property commonly known as 425 Broadway, situated in the City of Redwood City, County of San Mateo, State of California (the "Broadway Premises").

C. As part of the consideration for the Broadway Lease, Owner desires to give to At Home, and At Home desires to obtain from Owner, the option to lease all or certain portions of the conditions, and the option to acquire a portion of the Property on certain agreed terms and conditions.

D. Owner and At Home now desire to enter into this Agreement to set forth their agreement with respect to the above-described options and rights to make a first offer.

E. All capitalized terms no specifically defined in this Agreement shall have the same meanings given to them in the Broadway Lease.

NOW, THEREFORE, in consideration of the payment by At Home to Owner of the sum of One Hundred Dollars ($100) and for other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged by Owner, Owner and At Home hereby agree as follows:

Term. The term of this Agreement shall commence upon the execution of this Agreement by Owner and At Home, and shall expire upon the expiration or earlier termination of this Agreement in accordance with the terms set forth below; provided, however, that if the First Option is not validly and timely exercised in accordance with the provisions of Paragraph 2.5, then the First Option, the Second Option, and the Third Option (all as defined below), and the option to purchase the Second Option Subparcel, shall immediately expire (if this Agreement has not already expired or been terminated) on the First Option Notice Date (as defined below), and this Agreement shall automatically terminate as of the First Option Notice Date; if the Second Option is not validly and timely exercised in accordance with the provisions of Paragraph 2.6, then the Second Option and the Third Option, and the option to purchase the Second Option Subparcel, shall immediately expire (if this Agreement has not already expired or been terminated) on the Second Option Notice Date (as defined below); and if the Third Option is not validly and timely exercised in accordance with the provisions of Paragraph 2.7, then the Third Option shall immediately expire (if this Agreement has not already expired or been terminated) on the Third Option Notice Date (as defined below); and provided further, that if the owner of the Sears Parcel defaults under the option agreement with Owner for the Sears Parcel, this Agreement shall terminate with respect to the Sears Parcel. Notwithstanding