Why raise the heel at all, if the truss already spans?

To get the insulation over the wall plate without crushing it. At a standard heel the top and bottom chords converge to almost nothing where they meet the wall, so the insulation has to be squeezed into a wedge exactly where the roof meets the cold outside wall — and compressed insulation loses most of its value, producing a cold strip around the whole perimeter of the ceiling and the condensation and mould that follow it. A raised or energy heel keeps full depth right out to the wall plate, and it does something else useful at the same time: it lifts the underside of the roof away from the eaves so ventilation can still pass over the insulation rather than being blocked by it. It is a thermal and ventilation dimension that happens to be set in the truss shop.

Why does a standard (non-raised-heel) truss compress insulation at the eave?

Because on a standard truss the bottom chord meets the top chord right at the wall plate, leaving very little vertical space at the eave. Insulation gets compressed or thinned out right where the roof meets the wall, which is exactly where you want full depth to avoid a cold spot.

How does a raised heel fix this?

By adding vertical framing at the heel joint, which lifts the top chord above the bottom chord by an extra amount. In a raised-heel (energy-heel) truss this stack-up adds the desired full insulation depth on top of the bottom chord's own depth, keeping the insulation from being squeezed out near the wall.

Does this include ventilation baffle clearance above the insulation?

No — this is a simplified insulation-plus-bottom-chord stack-up only. Your truss manufacturer's engineering should add clearance for a ventilation baffle/chute above the insulation to maintain soffit-to-ridge airflow.

Materials & Quantities

Roof Truss Raised-Heel Height Calculator

Calculate the raised heel height needed on a roof truss to fit full-depth insulation at the eave.

Answers as you typeNo submit button
Every formula citedNamed published standards
Calculated in your browserNo account, nothing uploaded

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Market

Imperial · sales tax

Desired Insulation Depth at Eave

The full loose-fill or batt insulation depth you want maintained all the way out to the exterior wall line.

The depth you want AT THE EAVE, which is the hardest place to achieve it — the roof slopes down to meet the wall and the insulation is squeezed into the corner. This is the whole reason a raised heel exists. Enter the depth that meets the target R-value rather than the depth that fits: the point of the calculation is to find the heel height that makes the target possible.

Bottom Chord Depth

The depth (height) of the truss's bottom chord member.

The chord's own depth, which sits between the wall plate and the underside of the insulation and therefore eats into the space available at the eave. A 2×4 chord and a 2×6 chord differ by about 50 mm of heel height for the same insulation depth. Read it from the truss drawing rather than assuming, because the bottom chord is sized by the span and the ceiling load and is not a fixed member.

Recommended raised-heel height

15.5 in

Medium confidence

A simplified stack-up estimate — confirm the exact raised-heel height with your truss manufacturer's engineering, which also accounts for ventilation baffle clearance.

Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

Energy-heel (raised-heel) truss design: heel height = desired insulation depth at the eave + bottom chord depth, so full R-value insulation is maintained out to the wall line

Inputs used

Desired Insulation Depth at Eave: 12 in
Bottom Chord Depth: 3.5 in

Final result15.5 in

Confidence note: A simplified stack-up estimate — confirm the exact raised-heel height with your truss manufacturer's engineering, which also accounts for ventilation baffle clearance.

What this calculation does not cover

Every inch of heel raises the whole roof. The ridge, the gable end, the fascia and the top of the siding all go up by the amount calculated here, so on a site with a height limit, an eave line to match, or an existing roof to tie into, the heel is constrained from above before insulation depth gets a say.
The field asks for a DEPTH, and what an energy code sets is an R-value. Depth only becomes R through the material's R per unit of thickness, so switching from loose-fill fiberglass to dense-packed cellulose to rigid foam changes the heel needed for the same R considerably. Settle the insulation material first, then come back to this.
Past a certain height the heel stops being packing and becomes structure. That tall vertical at the bearing has to carry roof diaphragm shear down into the top plate, which means it gets blocked or sheathed to a detail on the truss engineering drawing. The stack-up here gives the dimension and stops there.

Add the equipment this sizes

This result is a specification — 15.5 in — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

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Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1

Regulatory standards & verification citations1

Energy-heel (raised-heel) truss design: heel height = desired insulation depth at the eave + bottom chord depth, so full R-value insulation is maintained out to the wall line

Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Now that you have the number

These guides cover the work this quantity is for — the first ones run this calculator inside the section that raises the question.

Checking Truss Shop Drawingsuses this calculator
Forty-one sheets and one seal: what to read on a truss design drawing, from the load block to the plate callout, before the pack reaches the saw.
Ordering Roof Trussesuses this calculator
A fabricator builds what the enquiry sheet says. On a vaulted extension in the lee of a taller roof, span, heel and the drift case decide it.
Framing a Gambrel, Mansard or King Post Roof

Still deciding? Raised-Heel Truss vs Baffles — the factors that actually differ, with no invented prices.

How to calculate roof truss raised-heel height in 3 steps

Desired Insulation Depth at EaveThe full loose-fill or batt insulation depth you want maintained all the way out to the exterior wall line.
Bottom Chord DepthThe depth (height) of the truss's bottom chord member.
Recommended raised-heel heightThe tool computes the recommended raised-heel height from those figures and shows the formula, its sources, and a confidence rating alongside it.

Recommended raised-heel height by desired insulation depth at eave

Page defaults, not your figures above.

Desired Insulation Depth at Eave	Recommended raised-heel height (in)
5 in	8.5
10 in	13.5
15 in	18.5
20 in	23.5

Frequently asked questions

Why raise the heel at all, if the truss already spans?: To get the insulation over the wall plate without crushing it. At a standard heel the top and bottom chords converge to almost nothing where they meet the wall, so the insulation has to be squeezed into a wedge exactly where the roof meets the cold outside wall — and compressed insulation loses most of its value, producing a cold strip around the whole perimeter of the ceiling and the condensation and mould that follow it. A raised or energy heel keeps full depth right out to the wall plate, and it does something else useful at the same time: it lifts the underside of the roof away from the eaves so ventilation can still pass over the insulation rather than being blocked by it. It is a thermal and ventilation dimension that happens to be set in the truss shop.
Why does a standard (non-raised-heel) truss compress insulation at the eave?: Because on a standard truss the bottom chord meets the top chord right at the wall plate, leaving very little vertical space at the eave. Insulation gets compressed or thinned out right where the roof meets the wall, which is exactly where you want full depth to avoid a cold spot.
How does a raised heel fix this?: By adding vertical framing at the heel joint, which lifts the top chord above the bottom chord by an extra amount. In a raised-heel (energy-heel) truss this stack-up adds the desired full insulation depth on top of the bottom chord's own depth, keeping the insulation from being squeezed out near the wall.
Does this include ventilation baffle clearance above the insulation?: No — this is a simplified insulation-plus-bottom-chord stack-up only. Your truss manufacturer's engineering should add clearance for a ventilation baffle/chute above the insulation to maintain soffit-to-ridge airflow.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — a confirmed fix gets a permanent check of its own, so the same mistake cannot come back.