Construction R-value Calculator (2024)

This webpage calculates the R-value of walls, roofs and suspended floors for most insulation material R-values. It uses the "isothermal planes" method, the same method as used in NZS4214:2006.

Some of the possible material combinations may not be suitable for actual constructions, i.e. EPS based claddings directly fixed on timber framing. Please make sure to select only appropriate material combinations.

If your construction is not listed, please send an e-mail to designnavigator@gmail.com with a description and a detail drawing (pdf) of it.

Please select the element type. Then choose the construction details and enter the R-value of the insulation either directly in the text box or by choosing a product from the right panel.

Floors
Walls
Roofs

Date:

By using this website you agree to the Design Navigator Terms and Conditions

' + '' + '
' + '

' + '' } InsProdTblString = '' + InsProdTblString + '

' + '' } InsProdTblString = '' + InsProdTblString + '

'; InsProdTblString = InsProdTblString.split('(c)').join('®'); InsProdTblString = InsProdTblString.split('(amp)').join('&'); // InsProdTblString = InsProdTblString.split('(TradeMark)').join('TM');$("#TblInsProducts").html(InsProdTblString); var WindowHeight = (navigator.appName == "Netscape") ? window.innerHeight : document.body.clientHeight; El("iddivInsulationFrameContainer").style.height = (WindowHeight - 20) + "px"; El('iddivInsulationFrameContainer').scrollTop = 0;//return InsProdTblString;}function DisableInsulationFilters() { $.ajax({ url: '../CRCUnFilterInsulation.php', type: 'POST', xhr: function() { var myXhr = $.ajaxSettings.xhr(); return myXhr; }, beforeSend: function () { }, success: function (response) { InsulationFilterDisabled = true; $("#idspnInsulationFilter").hide(); ShowAllInsulations(); }, data: null, error: function (response) { console.log('something went wrong 234: ', response); }, //Options to tell jQuery not to process data or worry about content-type. cache: false, contentType: false, processData: false });}function ShowAllInsulations() { $("#TblInsProducts table tr").show();}/* old XML version function setForm(MyProductStr) { let MyProduct = JSON.parse(Base64.decode(MyProductStr)); var ParentObject = new Object(); if(parent.CalculatorFrame === undefined){ ParentObject = window.parent; } else { ParentObject = window.parent.CalculatorFrame; } // RId = parent.CalculatorFrame.CurrentId; RId = ParentObject.CurrentId; if((RId === undefined) && (ParentObject.CurrentActiveR == null)) { alert('Please first place the cursor into the cell where you want to copy the insulation product in. Then click on the \'select\' button next to the insulation product.'); } else { if(!(RId === undefined)) { ProductString = RId.replace(/R_/,"Product_"); ProductString = ProductString.replace(/Txt/,"id"); if(ParentObject.document.getElementById(ProductString) === null) { alert('Please first place the cursor into the cell where you want to copy the insulation product in. Then click on the \'select\' button next to the insulation product.'); } else { ParentObject.document.getElementById(ProductString).innerHTML = MyProduct.name; ParentObject.document.getElementById(RId).dataset.thickness = MyProduct.T.value/1000.; ParentObject.document.getElementById(RId).dataset.ccompr = (typeof MyProduct.ccompr != "undefined") ? MyProduct.ccompr.value : 1; ParentObject.document.getElementById(RId).dataset.props = MyProductStr; ParentObject.document.getElementById(RId).value = MyProduct.R.value; ParentObject.document.getElementById(RId).focus(); } } else { // GF Mode and TableSelect Mode // if(!(ParentObject.CurrentActiveR == null)) { // GF mode ParentObject.CurrentActiveR['Lbl'].innerHTML = MyProduct.name + ""; ParentObject.CurrentActiveR['RBox'].dataset.thickness = MyProduct.T.value/1000.; ParentObject.CurrentActiveR['RBox'].dataset.ccompr = (typeof MyProduct.ccompr != "undefined") ? MyProduct.ccompr.value : 1; ParentObject.CurrentActiveR['RBox'].dataset.props = MyProductStr; ParentObject.CurrentActiveR['RBox'].value = MyProduct.R.value; ParentObject.CurrentActiveR['RBox'].focus(); $(".tblElementTable tbody .ElementConstr").trigger("change"); // for TableSel Mode // } } } return false;}*/function setFormJSON(MyProductStr) { let MyProduct = JSON.parse(Base64.decode(MyProductStr)); var ParentObject = new Object(); if(parent.CalculatorFrame === undefined){ ParentObject = window.parent; } else { ParentObject = window.parent.CalculatorFrame; } // RId = parent.CalculatorFrame.CurrentId; RId = ParentObject.CurrentId; if((RId === undefined) && (ParentObject.CurrentActiveR == null)) { alert('Please first place the cursor into the cell where you want to copy the insulation product in. Then click on the \'select\' button next to the insulation product on the right panel.'); } else { if(!(RId === undefined)) { ProductString = RId.replace(/R_/,"Product_"); ProductString = ProductString.replace(/Txt/,"id"); if(ParentObject.document.getElementById(ProductString) === null) { alert('Please first place the cursor into the cell where you want to copy the insulation product in. Then click on the \'select\' button next to the insulation product.'); } else { ParentObject.document.getElementById(ProductString).innerHTML = MyProduct.ProdName; ParentObject.document.getElementById(RId).dataset.thickness = MyProduct.T/1000.; ParentObject.document.getElementById(RId).dataset.ccompr = (typeof MyProduct.ccompr != "undefined") ? MyProduct.ccompr : 1; ParentObject.document.getElementById(RId).dataset.mat = Base64.encode(JSON.stringify(MyProduct.Mat)); ParentObject.document.getElementById(RId).dataset.isproduct = "true"; ParentObject.document.getElementById(RId).value = MyProduct.R; ParentObject.document.getElementById(RId).focus(); } } else { // GF Mode and TableSelect Mode // if(!(ParentObject.CurrentActiveR == null)) { // GF mode ParentObject.CurrentActiveR['Lbl'].innerHTML = MyProduct.ProdName + ""; ParentObject.CurrentActiveR['RBox'].dataset.thickness = MyProduct.T/1000.; ParentObject.CurrentActiveR['RBox'].dataset.ccompr = (typeof MyProduct.ccompr != "undefined") ? MyProduct.ccompr : 1; ParentObject.CurrentActiveR['RBox'].dataset.mat = Base64.encode(JSON.stringify(MyProduct.Mat)); ParentObject.CurrentActiveR['RBox'].dataset.isproduct = "true"; ParentObject.CurrentActiveR['RBox'].value = MyProduct.R; ParentObject.CurrentActiveR['RBox'].focus(); $(".tblElementTable tbody .ElementConstr").trigger("change"); // for TableSel Mode // } } } return false;}//-->

The listed R-values are based on manufacturer information.

The selected R-value will be automatically transfered into the currently selected cell of the construction calculator.

Construction R-value Calculator (2024)

References