The detail makes the difference
Understand heat loss at the junctions.
Good insulation is only part of the picture. The way walls, floors, roofs and openings meet also affects a building’s thermal performance.
We model construction junctions and provide calculated psi values for use in SAP and SBEM assessments, with practical advice where a detail could be improved.
Discuss your project →
What you receive
Project-specific details, clearly explained.
Junction modelling
A model based on the proposed construction, material properties, dimensions and insulation arrangement.
Calculated psi values
Linear thermal transmittance values and supporting information for your energy assessor, using BR 497 methodology.
Practical design advice
Guidance on junction improvements and temperature-factor assessment where included in the agreed scope.
Feedback on the Barlings service
“Always happy to answer any queries we have; the service and information they provide is excellent.”Kirsty Uttley · Barlings KWA client
Choose the right route
A bespoke calculation or an existing detail?
Your own construction detail
Send the proposed junction drawing and material information. We can quote for modelling the specific detail used on your project.
Request a bespoke calculation →Our calculated detail library
Browse the available licensed details. Check the construction, materials and dimensions carefully against your design before choosing one.
View the current detail library →Junctions we can assess
Look beyond the wall U-value.
Floors and walls
Ground-floor edges, wall-to-floor connections and changes in construction.
Roofs and upstands
Eaves, wall-to-roof connections and flat-roof upstand details.
Windows and doors
Heads, jambs, sills and lintels around openings.
Bespoke interfaces, steel penetrations and other non-standard junctions can also be discussed. Send the detail so we can confirm the scope.
A straightforward process
From a construction detail to a usable result.
Share the junction details
Provide dimensioned drawings, material specifications and the junctions you need assessed.
Model and review
We build the thermal model and review the result, discussing relevant detail changes where required.
Receive the calculations
We provide the agreed psi values and supporting report for your project team and energy assessor.
Useful answers before you enquire
Your thermal bridging questions.
What is the difference between a U-value and a psi value?
A U-value describes heat transfer through an area of construction. A psi value describes the additional heat transfer associated with a linear junction, expressed in W/mK.
Will calculated psi values always improve my SAP result?
Not necessarily. A calculation represents the particular junction and may differ from a default assumption. The result depends on the construction and how it is detailed.
Can I use a detail from your library on any project?
No. The proposed construction must match the scope of the calculated detail, including the relevant materials, dimensions and insulation arrangement. Contact us if you are unsure.
What do you need to quote?
Send the junction drawings, dimensions, material build-ups and properties, plus the number of distinct details and your deadline. We’ll confirm any missing information.
Can you assess condensation risk?
Temperature-factor checks can be included where required. Tell us the purpose of the assessment so we can agree the appropriate scope.
Which calculation methodology do you use?
Our thermal-junction calculations follow BRE BR 497 conventions. Read about the BRE methodology.
Coordinate your assessments
Use your junction results in the wider project.
We also provide SAP assessments for dwellings and SBEM calculations for commercial buildings. Tell us which assessment the junction values will support so we can agree the information needed with your project team.
Your project, your quotation
Send us your junction details.
Tell William and Kerry which details need assessing and whether the results are for SAP, SBEM or another project requirement. We’ll confirm the scope and provide a quotation.
Useful details: junction drawings · dimensions · material properties · number of details · deadline