Section 29. Subordination of liens to subsequent mortgage

In case an owner
  of real property upon which an improvement is being or  has  been  made,
  desires  to obtain a loan by executing and delivering a bond or bonds or
  note or notes secured by a mortgage upon such real property, or any part
  thereof, and in case lienors having mechanics' liens against  such  real
  property, or any part thereof, notices of which have been filed prior to
  the  recording  of  such  mortgage,  and  which said liens have not been
  discharged as in this article provided, shall, to the extent of at least
  fifty-five per centum of the aggregate amount for which notices of  such
  liens  have  been  so filed, by an instrument or instruments in writing,
  duly acknowledged, designate  and  authorize  one  or  more  persons  to
  consent  to the execution and delivery of such bond and mortgage or note
  and mortgage, and in case the consent in writing, duly acknowledged,  of
  such  person  or  persons to the execution and delivery of such bond and
  bonds and mortgage or note and notes and mortgage shall be filed in  the
  office  of the clerk of the county where such real property is situated,
  together with such instrument or instruments of  designation,  then  all
  mechanics'  liens  for  labor performed and materials furnished prior to
  the recording  of  such  mortgage  whether  notices  thereof  have  been
  theretofore or are thereafter filed, shall be subordinate to the lien of
  such  bond  or  bonds  and mortgage or note or notes and mortgage to the
  extent of the full amount which shall be  advanced  thereunder  provided
  such  mortgage  contains the covenant prescribed in subdivision three of
  section thirteen of this chapter. In case  such  person  or  persons  so
  designated and authorized shall so consent to the execution and delivery
  of  such  bond and mortgage or note and mortgage but on condition that a
  sum of money be deposited with the clerk of such county, and such sum is
  so deposited, the county clerk, upon such payment, shall forthwith enter
  upon the lien docket, indexed with the name  of  the  owner,  the  facts
  relating  to such payment. A deposit of money made as prescribed in this
  section shall be repaid to such owner or his assignee upon the discharge
  or release of all mechanics' liens, judgments  and  attachments  against
  the  property.  All  deposits  of money made as provided in this section
  shall be considered as paid into court  and  shall  be  subject  to  the
  provisions  of  law  relative to the payment of money into court and the
  surrender of such money by order of the court. The court  shall  in  any
  action  brought to foreclose any of such liens, or in any action brought
  to recover such deposit or any part thereof, direct the payment of  such
  sum  so  deposited  to the persons whose mechanics' liens, judgments, or
  claims secured by attachment shall have been established  on  the  trial
  and  the  amount  so  paid shall be credited upon such mechanics' liens,
  judgments and claims. Upon such filing of such consent, as  hereinbefore
  provided,  the lien of all judgments and attachments affecting such real
  property and all claims and liens acquired in any proceedings upon  such
  judgments  shall  be  subordinate  in  like manner and to like extent as
  hereinbefore  in  this  section  provided  for  the   subordination   of
  mechanics' liens, and any attachment issued or judgment recovered upon a
  claim, which, in whole or in part, is not for materials furnished, labor
  performed  or moneys advanced for the improvement of such property shall
  be subordinate to all  mechanics'  liens  thereon,  and  shall  also  be
  subordinate  to all judgments recovered upon and attachments issued upon
  claims for materials furnished, labor performed or moneys  advanced  for
  the  improvement  of  such real property. Any lienor having a mechanic's
  lien against real property may subordinate such lien to  any  subsequent
  mortgage  thereon  by  a certificate duly acknowledged or proved stating
  that such lien is subordinated, which certificate shall be filed in  the
  office  where the notice of lien is filed. Upon filing such certificate,
  the county clerk in the office where the same is filed  shall  note  the

  fact  of  such  filing  in  the  "lien  docket"  in  the  column  headed
  "proceedings had," opposite the docket of such lien.