The issue was whether these additions violated the section of the easement that prohibited "extension of the existing structure or erection of additional structures."28 The District of Columbia Court of Appeals found the term "extension" ambiguous, because it could include increasing the density of the house, as Arnold had done, or could be limited to expanding the outer frame or "envelope" of the [...] The Court of Appeal applied the rule in favour of the free use of land, and the rule requiring the resolution of ambiguities in favour of the 26 Arnold, supra note 8 at 797. [...] In particular, in Bennett v. Commissioner of Food and Agriculture ("Bennett") the Supreme Judicial Court of Massachusetts made the following comments, in obiter, regarding conservation restrictions: Where the beneficiary of the restriction is the public and the restriction reinforces a legislatively stated public purpose, old common law rules barring the creation and enforcement of easements in gr [...] Rather than discuss the interpretive presumption, the court commented as follows: In addition to its social benefits, a conservation restriction yields an economic benefit to the grantor of the restriction and successor owners of the property... In return for that benefit to the owner, it is reasonable that the conservation restriction be protected against expedient exemptions which defeat the purpo [...] Noting that the town code included the amended regulations, from which the covenant borrowed language, the court applied the code's definition of unit to the easement.