Choose a coherent system
Natural, intermittent, continuous mechanical and heat-recovery strategies have different design and installation needs. Mixing assumptions from different systems creates gaps.
Ventilation performance
Part F ventilation support
Ventilation calculations and design coordination, with installation and commissioning evidence planned alongside SAP and overheating work.
When you need this work
Ventilation needs to provide adequate air quality in the building that will actually be constructed. System choice, duct routes, terminals, controls, acoustics and commissioning all influence the outcome.
We review the dwelling, proposed ventilation system and applicable guidance, then calculate or check the required rates within the commissioned scope. Coordination with Part L and Part O matters: fan power, heat recovery, infiltration assumptions, purge ventilation and window operation can appear across several assessments. Installation design and commissioning must remain with appropriately competent project parties.
What we check
Make routes buildable
Duct size, length, bends, insulation, terminals, access and noise should be resolved in the design. A nominal fan selection cannot compensate for an impractical route.
Complete the evidence
Installed systems need the relevant inspection, testing, commissioning and handover information. We identify required inputs for related energy calculations.
Common coordination issue
A fan’s stated capacity does not establish the installed system performance. Duct routes, terminals, controls and commissioning information need to support the rates and system assumed by the assessments.
What you receive
Design review or calculation
The agreed Part F ventilation output with required rates and assumptions.
Coordination comments
Issues affecting energy, overheating, noise or installation feasibility.
Evidence schedule
Relevant commissioning and handover items needed from the responsible installer or project team.
Getting started
What we need
Dwelling information
Plans, room schedule, floor areas, wet-room locations, airtightness strategy and occupancy assumptions required by the method.
Ventilation design
System type, fan or unit data, duct layouts, terminals, controls and relevant acoustic information.
Coordination data
SAP assumptions, Part O strategy and commissioning programme where these interact with the ventilation design.
Before commissioning
Do you install ventilation systems?
No. We provide the commissioned assessment and coordination support. Installation and commissioning remain with the appropriate project parties.
Can Part F and Part O use different window assumptions?
They address different functions, but inconsistent or unrealistic operation should be resolved. We coordinate the relevant inputs where both are commissioned.
Is commissioning information needed for SAP?
Final energy inputs must reflect the installed system and required evidence. We confirm the project-specific information needed.
Sources and further reading
Use the edition, jurisdiction and assessment route that apply to the project. Publication of newer guidance does not automatically change an existing project’s requirements.
Resolve the ventilation strategy before installation
Send the dwelling plans, system proposal and the stage at which you need design or completion support.