(1) Application of the child support schedule. The child support schedule shall be applied:
(a) In each county of the state;
(b) In judicial and administrative proceedings under this title or Title
13 or
74 RCW;
(c) In all proceedings in which child support is determined or modified;
(d) In setting temporary and permanent support;
(e) In automatic modification provisions or decrees entered pursuant to RCW
26.09.100; and
(f) In addition to proceedings in which child support is determined for minors, to adult children who are dependent on their parents and for whom support is ordered pursuant to RCW
26.09.100.
The provisions of this chapter for determining child support and reasons for deviation from the standard calculation shall be applied in the same manner by the court, presiding officers, and reviewing officers.
(2) Written findings of fact supported by the evidence. An order for child support shall be supported by written findings of fact upon which the support determination is based and shall include reasons for any deviation from the standard calculation and reasons for denial of a party's request for deviation from the standard calculation. The court shall enter written findings of fact in all cases whether or not the court: (a) Sets the support at the presumptive amount, for combined monthly net incomes below five thousand dollars; (b) sets the support at an advisory amount, for combined monthly net incomes between five thousand and seven thousand dollars; or (c) deviates from the presumptive or advisory amounts.
(3) Completion of worksheets. Worksheets in the form developed by the administrative office of the courts shall be completed under penalty of perjury and filed in every proceeding in which child support is determined. The court shall not accept incomplete worksheets or worksheets that vary from the worksheets developed by the administrative office of the courts.
(4) Court review of the worksheets and order. The court shall review the worksheets and the order setting support for the adequacy of the reasons set forth for any deviation or denial of any request for deviation and for the adequacy of the amount of support ordered. Each order shall state the amount of child support calculated using the standard calculation and the amount of child support actually ordered. Worksheets shall be attached to the decree or order or if filed separately shall be initialed or signed by the judge and filed with the order.