Round up to nearest quarter hour

I have tried simplifying this as I just want to produce a vlaue that says x hours and x minutes - such as "2hr 15min"

So, I tried removing the formating and using Math.round and Modulo to produce hour and minute values, then massaging those.

This is what I have so far, but it isn't working out - if I fill in any value into one of the room fields, the RecommendedHours becomes "2hr".

//Room fields are dropdowns with values from 1-10

var st = this.getField("Storeys").value * 10; //clean time fo rstairs and hallways

var ki = this.getField("Kitchen").value * 30; //clean time for kitchen

var kd = this.getField("K/D").value * 30; //clean time for kitchen/diner

var sw = this.getField("S/W").value * 10; //clean time for study/workroom

var be = this.getField("Bed").value * 10; //clean time fo rbedrooms

var di = this.getField("Dining").value * 20; //clean time for dining rooms

var lf = this.getField("Living").value * 20; //clean time for living/family room

var co = this.getField("Cons").value * 20; //clean time for conservatory

var fb = this.getField("FullBath").value * 30;  //clean time for full bathrooms

var sh = this.getField("Shower").value * 20; //clean time for shower rooms/en-suites

var ba = this.getField("BathOnly").value * 20; //clean time for bathrooms without shower

var wc = this.getField("W/C").value * 10; //clean time fo rutility rooms and w/c

var prep = 5; //add 5 minutes for prep time

//get total minutes for clean times

var TotalMin = st + ki + kd + sw + be + di + lf + co + fb + sh + ba + wc + prep;

//get hours from total minutes

var hr = Math.floor(TotalMin / 60);

//get remaining minutes after separating hours

var min = TotalMin % 60;

//if all room fields are blank, RecommendedHours value should be ""

if (st == "" && ki == "" && kd == "" && sw == "" && be == "" && di == "" && lf == "" && co == "" && fb == "" && sh == "" && ba == "" && wc == "") {event.value = "";}

//Minimum value of RecommendedHours must be 2 hours

else if (hr = 1) {event.value = "2hr";}

//If Hours are 2 or more

//If minutes is greater than 0 and equal to or less than 15, round up minutes to 15

else if (hr >= 2 && min > 0 && min <= 15) {event.value = hr + "hr" + " " + "15min";}

//If minutes is greater than 15 and equal to or less than 30, round up minutes to 30

else if (hr >= 2 && min > 15 && min <= 30) {event.value = hr + "hr" + " " + "30min";}

//If minutes is greater than 30 and equal to or less than 45, round up minutes to 15

else if (hr >= 2 && min > 30 && min <= 45) {event.value = hr + "hr" + " " + "45min";}

//If minutes is greater than 45, round up to next hour

else if (hr >= 2 && min > 45) {event.value = (hr + 1) + "hr";}