Passivhaus & NZEB Designers

At Bennett Freehill, we lead the UK drive in delivering high-performance building services engineering, with deep expertise in Passivhaus and Nearly Zero Energy Building (NZEB) design. Our team merges technical rigour with practical experience, helping clients, architects and design teams achieve ambitious sustainability goals from concept through completion.

What We Offer

• Holistic & Integrated Design Advice
  We provide early-stage consultancy on fabric, systems, thermal bridging, airtightness, ventilation, and renewable energy. This ensures that Passivhaus / NZEB goals are embedded from the outset, reducing design changes, delays and cost over-runs.
• Compliance, Verification & Performance Monitoring
  • Passivhaus assessments (including PHPP modelling)
  • Thermal modelling, energy use predictions and NZEB compliance analysis
  • On-site monitoring, testing and verification (airtightness, blower-door, thermal imaging etc.) to ensure performance matches design intent
• Risk Mitigation & Value Engineering
  With hands-on experience across multiple Passivhaus and NZEB projects, we help clients anticipate and manage technical and contractual risks. We balance high performance with cost effectiveness, advising on materials, systems and construction sequencing to deliver optimal value without compromising standards.
• Renewable Energy & Low Carbon Systems
  We integrate renewables (solar, heat pumps, etc.), ensure mechanical & electrical systems are optimally sized, and advise on energy procurement strategies. Our knowledge of low carbon generation and system control helps reduce both operational carbon and energy bills.
• Collaborative Working & Technical Excellence
  Our approach is highly collaborative — working closely with architects, contractors, certifiers and other design disciplines. We emphasise buildability, quality assurance and efficient project delivery, underpinned by clear technical documentation and standards.