Overheating is the failure mode that airtight, well-insulated buildings are most exposed to, and it is almost always cheaper to design out than to cool away. Once glazing areas and opening types are fixed, the remaining options are mechanical.
We build a dynamic 3D thermal model and run it against the criteria that apply to the building type — TM59 for residential, TM52 for commercial, TGD-020 for schools — so the risk is quantified while shading, opening type and free area are still design decisions.
Who this is for
Residential and apartment schemes
TM59 assesses dwellings room by room across the summer. Single-aspect south and west-facing units are where schemes usually fail, and that is far easier to resolve on the model than on site.
Commercial and mixed-use projects
TM52 applies the adaptive comfort criteria to non-domestic spaces, and the results feed directly into decisions about whether mechanical cooling is needed at all.
Schools and academic buildings
TGD-020 sets the assessment basis for school buildings, where occupancy density and the summer timetable both drive the result.
How the process works
- 01Build the dynamic 3D thermal model of the building
- 02Run the summer assessment against the relevant criteria
- 03Identify which rooms and orientations fail, and by how much
- 04Test passive measures first — shading, opening type, free area
- 05Report the compliant option and the window usage it assumes
Frequently asked questions
What does an overheating assessment actually tell me?
Internal temperatures across the summer, the number of hours above the limit criteria, the percentage of annual hours affected, and the instantaneous peak temperatures. That is enough to say which rooms fail, by how much, and what fixes them.
What is the difference between TM59 and TM52?
TM59 is the CIBSE methodology for assessing overheating risk in homes; TM52 covers non-domestic buildings using adaptive comfort criteria. Schools in Ireland are assessed under TGD-020 instead.
When is the right time to run one?
Before glazing areas, opening types and shading are fixed. Run at that point the study can steer passive measures; run afterwards it usually just evidences the need for cooling.
Can overheating be solved without mechanical cooling?
Often, yes. We test passive measures first — shading, opening type, ventilation free area and the window usage patterns the model assumes — and only conclude that cooling is required when the passive options have been exhausted.
Other services
Energy performance and BER
Domestic and non-domestic BER, Part L and NZEB compliance modelling, and IES thermal modelling — from baseline assessment through to SEAI registration.
03Daylight and building performance
Daylight, thermal comfort and CIBSE load modelling — Radiance and IES analysis used to improve comfort, evidence compliance and size the plant properly.
04Planning and sustainability consultancy
Climate Action Energy Statements, Sustainability Reports, Building Lifecycle Reports and the supporting technical analysis a planning application needs.
05LEED, BREEAM and WELL certification
Accredited across all three systems — certification strategy backed by energy modelling, credit tracking and technical consultancy, from one point of contact.
06Renewable energy
Solar PV, battery optimisation, solar thermal and district heating — specified against the building as modelled, not against available roof area.
Talk to the team
Tell us about the project and the stage it is at. We'll set out what the analysis would cover and what it would tell you.
Request a quote