We exist to keep buildings worth owning
CSR Sustain brings together building performance engineers, energy assessors and property specialists to help organisations understand, improve and manage the buildings they own, manage or operate.
Our services span energy compliance and certification, portfolio intelligence, decarbonisation planning, M&E and HVAC engineering, technical project management and ongoing building optimisation. We connect these services to help clients identify risks, prioritise investment and turn technical recommendations into practical improvements.
We want a market in which energy performance is not an annual compliance chore but a managed, measurable property of every asset — where owners know exactly how their buildings perform, what it costs them, and what to do next.
We combine energy compliance, engineering design, retrofit delivery and continuous optimisation into a single relationship — removing the gaps between suppliers where cost, carbon and accountability are usually lost.
We believe energy performance should be understood, not endured: a living measure of every building rather than a once-a-year obligation. Owners deserve clear insight into how their estates operate, what that is costing them, and the smartest next step.
We commit to delivering compliance, design, retrofit and ongoing optimisation through one accountable team, closing the handovers between providers where savings, carbon reductions and responsibility often slip away.
Compliance is the floor. Performance is the point.
A certificate tells you what a building was on the day it was assessed. It tells you almost nothing about how it actually runs, what it wastes, or what it will cost you when the standard rises again.
We started CSR Sustain because owners kept asking the same question after every survey. Answering that properly means engineering capability, not just assessment — and staying involved long after the certificate is issued.
Five values that decide how we work
These aren't posters on a wall — they're the tests we apply when a decision is difficult.
Accountability, not hand-offs
We stay on the hook from baseline to result. If something falls between disciplines, that is our problem to solve — not the client's problem to project-manage.
Evidence over assertion
We measure rather than claim. Every recommendation is grounded in survey data or monitored performance, and every result is reported in numbers a client can take to their board.
Engineering rigour
Energy performance is an engineering problem before it is a reporting one. We design to how buildings actually behave, not to how a model assumes they will.
Independence in the owner's interest
We work for the asset owner. Our advice is not shaped by what is easiest to install or most profitable to supply.
In it for the long term
Buildings don't improve in a single project. We design relationships that last across a decade of tightening standards, not a single transaction.
Specialists, joined up
CSR Sustain leads and remains accountable for delivery. Our partners bring depth where depth is needed.
Portfolio intelligence
Data and analytics that identify which assets carry the greatest risk, where performance is being lost and where intervention delivers the greatest value.
Compliance & certification
Our own accredited assessors and consultants deliver statutory certification and independent building performance benchmarking across your portfolio.
Engineering & delivery
Chartered engineering, M&E design and technical project management capability for delivering retrofit at portfolio scale.
Building Optimisation
Continuous monitoring, fault detection and engineering-led optimisation to improve building performance and prevent energy drift.
Who you'll be working with
Gary Cleary, Managing Director
Founder and Managing Director with 40 years’ experience across property, construction, investment and energy compliance. Leads CSR Sustain’s strategic direction and brings extensive experience in energy assessment, property performance, portfolio management and identifying legacy issues across commercial property.
Luke Cleary, Technical Director
Technical Director with experience across mechanical engineering, building performance, project management and building analytics in the UK and Australia. Leads CSR Sustain’s technical delivery, engineering and building performance work, with particular expertise in HVAC, controls, energy optimisation and client-side project management across commercial property.
Alireza Akbari, Building Performance Engineer
Building Performance Engineer with international experience in energy engineering, building performance and low-carbon retrofit. Leads non-domestic EPCs, energy assessments and performance analysis at CSR Sustain. MSc Energy Engineering, BEng HVAC & Building Services Engineering, NDEA Level 3 & 4.
Michelle Booth, Office Manager
Office Manager with CSR Sustain since 2008 with experience managing a range of high-spec property portfolios. Provides dedicated project-by-project oversight and is the main point of contact for a broad range of successfully handled projects. Manages both client and account outreach, alongside project, people management and day-to-day administration.
Craig Kefford, Energy Consultant
Craig has been with CSR Sustain since 2006 and has a strong hands-on engineering background. He brings extensive practical experience of surveying buildings, understanding their systems and assessing how they operate in practice. Craig plays a key role in delivering CSR Sustains energy assessment and certification work, combining technical knowledge with a practical, site-based approach.
