Independent Energy & Sustainability Consultancy

Expert guidance in Energy Efficiency, Decarbonisation and Building Performance

Specialist consultancy for Net Zero Carbon, Dynamic Simulation Modelling and Energy & Sustainability solutions across the UK and Europe

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100+ Buildings assessed
30%+ Average energy savings identified
13+ Years of building physics expertise
UK & EU Bilingual service across Europe
ABOUT US

About BeLeaf Consulting

BeLeaf Consulting is an independent energy and sustainability consultancy supporting fellow consultancies and project teams to improve building performance, reduce carbon, and achieve Net Zero and ESG objectives.

We translate ambitious energy targets into clear, technically robust, and financially viable strategies for both as-designed and operational buildings.

Our work is grounded in engineering expertise and asset-specific analysis, ensuring practical, measurable outcomes aligned with real-world performance.

Working across the full asset lifecycle, we specialise in energy efficiency, decarbonisation and building optimisation, acting as a trusted technical partner through specialist modelling, independent review and additional technical capacity when required.

Professional Accreditations

CIBSE LCEA & LCC Level 5Lifecycle Carbon & Cost Assessment
ESOS Lead AssessorEnergy Savings Opportunity Scheme
NABERS UK AssessorNational Australian Built Environment Rating System
Certified Passivhaus ConsultantCertified Passive House Consultant
DEC AssessorDisplay Energy Certificate Assessor
BREEAM APBREEAM Accredited Professional
CSRD FundamentalsCorporate Sustainability Reporting Directive
RESET APRESET Accredited Professional
Jose Alvarez Arregui

Jose Alvarez Arregui

Founder & Managing Director

Mechanical Engineer (MCIBSE, CEng) specialised in Energy Efficiency and Sustainability in Building Design

13+ years of experience in building physics and energy consultancy

Former Head of Building Physics at top-tier UK consultancies

WHAT WE DO

Our Services

Comprehensive energy and sustainability consulting services to transform your buildings and achieve your Net Zero goals.

WHY BELEAF

What sets us apart

We combine technical rigour with commercial thinking — because the best sustainability strategy is also the most financially sound one.

Profitability at the core

Every measure is assessed for economic return, not just carbon impact. Sustainability must make financial sense — and with the right analysis, it always can.

Competitive differentiation

Energy efficiency is not just regulatory compliance. It is a competitive advantage, a stronger commercial proposition and long-term protection of asset value.

High-level technical rigour

CEng MCIBSE, IES VE, CIBSE methodologies. Every recommendation is grounded in real asset data and advanced energy modelling — not generic reports.

Fully independent

No commercial affiliations, no product bias. Our advice is always aligned with the client's technical and financial interests — nothing else.

OUR EXPERIENCE

Case Studies by Sector

Proven expertise across diverse building types and sectors, delivering measurable results for our clients.

Energy optimisation for multi-tenant offices, CRREM roadmaps, Part L compliance verification, and tenant engagement strategies for large commercial portfolios.

Example projects:

  • Multi-tenant office CRREM alignment
  • Part L 2021 compliance assessments
  • Mixed-use development energy strategies

Net Zero audits, overheating risk analysis using TM59/CIBSE methodologies, and lifecycle carbon reduction strategies for residential developments.

Example projects:

  • Energy audits and energy-saving plans
  • Overheating and thermal comfort analysis
  • HVAC, domestic hot water, ventilation and controls optimisation
  • Decarbonisation roadmaps with estimated investment, savings and payback period

Airport terminal energy studies, rail station assessments, natural ventilation feasibility analysis, and infrastructure decarbonisation strategies.

Example projects:

  • Airport terminal energy optimisation
  • Rail station thermal comfort studies
  • Natural ventilation feasibility analyses

BREEAM assessments, thermal comfort studies, and retrofit analysis for educational institutions and public sector buildings.

Example projects:

  • University BREEAM certifications
  • Public building energy audits
  • School retrofit feasibility studies
LET'S START

Let's Work Together

Ready to transform your buildings into sustainable, high-performance assets? Get in touch to discuss your project requirements.

Book a Consultation

Schedule a free 30-minute call to discuss your sustainability goals.

Book a Call