Energy Savings Opportunity Scheme ( ESOS)
As UK summers become hotter, commercial building overheating directly threatens tenant comfort, operational productivity, and long-term asset value.
HollenPlus delivers chartered surveyor-led heat resilience strategies that eliminate thermal risk.
Powered by CIBSE TM52 criteria and Level 5 Dynamic Simulation Modelling (DSM), we deploy cost-effective building adaptations that protect your properties, prevent premature HVAC replacement, and safeguard investment returns and liquidity.
Why Chose HollenPlus?
We don't just export CIBSE TM52 pass/fail charts.
We use this analysis to create tailored, cost effective building adaptation strategies, which minimise cost and maximise returns.
We combine Level 5 Dynamic Simulation Modelling with Chartered Surveyor expertise, translating complex thermal climate data directly into asset value protection, CAPEX strategy, and lease risk mitigation.
The Commercial Overheating Challenge in UK Real Estate
Rising summer temperatures and volatile heatwaves across the UK are exposing structural vulnerabilities in commercial office blocks, retail spaces, and mixed-use portfolios. Traditional air conditioning systems are struggling to keep pace, driving up operational costs and energy consumption while failing to prevent internal temperature spikes. For asset managers, unmanaged overheating creates immediate financial and operational liabilities.
Key Commercial Risks:
Tenant Dissatisfaction & Lease Breaks: Persistent thermal discomfort leads to formal complaints, reduced workplace productivity, and early lease terminations.
Escalating CAPEX & Energy Bills: Relying solely on continuous mechanical cooling stresses existing HVAC plant, leading to premature equipment failure and elevated carbon emissions.
Yield Erosion & Stranded Asset Risk: Buildings that fail basic thermal comfort standards risk lower re-letting values, longer void periods, and valuation discounts during acquisition or refinancing.
CIBSE TM52 Thermal Modelling & In-House Level 5 DSM
Rather than relying on generic assumptions or invasive physical interventions, HollenPlus diagnoses thermal vulnerability using advanced building physics. Our approach is anchored in CIBSE TM52 (The Limits of Thermal Comfort: Avoiding Overheating in European Buildings), the definitive UK benchmark for commercial spaces.
Our Technical Approach:
In-House Level 5 Dynamic Simulation Modelling (DSM): We build precise 3D digital twins of your property, analysing hourly solar gains, building fabric performance, and internal heat loads across occupied hours.
Stress-Testing Against Future Weather Data: We model your asset against Met Office future climate scenarios (UKCP18 2030s and 2050s datasets) to ensure your building remains resilient throughout typical 10- to 15-year lease cycles.
Targeted Zone Analysis: We identify specific overheating hotspots within floorplates, such as heavily glazed south-facing perimeter zones allowing for localised, low-cost interventions.
Low-CAPEX Building Adaptation & Passive Cooling Strategies
Replacing central plant or adding heavy air conditioning is often prohibitively expensive and counterproductive to carbon reduction goals.
HollenPlus prioritises low-CAPEX adaptations that intercept heat before it enters the building envelope or manage internal gains efficiently.
Core Intervention Solutions:
Solar Heat Gain Reduction: Implementing high-performance window solar films, micro-louvres, and external shading (brise soleil) to block solar radiation without sacrificing daylighting.
Envelope & Roof Optimisation: Applying high-albedo reflective roof coatings (cool roofs) and improving envelope insulation to minimise thermal absorption.
Operational & BMS Tweaks: Optimising Building Management System (BMS) logic to introduce measures such as weather compensation and automated night-purge ventilation, drawing in cooler ambient air overnight to reset internal thermal mass.
Hybrid Cooling Integration: Combining passive measures with targeted, high-efficiency localised cooling to supplement existing HVAC infrastructure.
The HollenPlus Differentiator: Chartered Surveyor Leadership
Most commercial property firms fall into one of two categories: engineering consultancies that output dense, technical data charts, or surveying practices that lack advanced thermal physics capability.
HollenPlus bridges this gap by combining MRICS Chartered Surveyor expertise with certified Level 5 DSM thermal modelling in-house.
Why This Matters for Your Portfolio:
Commercial Translation: We do not just export CIBSE TM52 pass/fail charts. We translate thermal climate data into strategies which directly protect and improve asset values and returns, liquidity and CAPEX planning.
Valuation & Due Diligence: Our findings are integrated with property due diligence, MEES compliance, CRREM alignment, and overall ESG asset strategies.
Professional Accountability: Our strategies and recommendations give investment committees and lenders complete confidence.
Protect Your Commercial Yields Against Climate Risk
Don't wait for tenant complaints or soaring summer cooling bills to evaluate your portfolio's thermal resilience.
HollenPlus provides clarity, compliance and actionable adaptation strategies, from individual buildings to nationwide portfolios.
FAQs
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Rising summer temperatures, increased building airtightness, and extensive glazing mean commercial assets are trapping excess heat. Overheating leads to tenant discomfort, reduced workplace productivity, elevated operational costs, and premature asset depreciation. Proactive heat resilience strategies ensure your building remains comfortable, energy-efficient, and compliant without over-relying on carbon-intensive HVAC systems.
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Unmitigated heat risks create ‘stranded assets’, properties that face high tenant turnover, as well as expensive retrofits, or lower BREEAM and GRESB ratings. By integrating thermal modelling into your asset management strategy and overheating analysis, you safeguard your rental income, keep tenants satisfied and protects your portfolio’s value.
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CIBSE TM52 (Technical Memorandum 52) is the industry-standard benchmark used to evaluate overheating risk in non-domestic buildings. It uses dynamic thermal simulation to test how a building performs under realistic summer weather data. If you are undertaking major refurbishments, applying for planning permission, or seeking high BREEAM ratings, a TM52 assessment is typically required.
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Heavy reliance on active mechanical cooling leads to soaring energy bills, higher carbon emissions, and potential grid capacity bottlenecks. Furthermore, if outdoor temperatures breach the design parameters of your chillers, the system can fail altogether. Overheating assessments identify passive cooling measures, such as solar shading, specialised glazing films, and night-purge ventilation, that drop mechanical load and lower operational expenditure.
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The right overheating solutions depend on your building's specific orientation and facade type. Common high-ROI interventions include:
External architectural shading or solar control window films
BMS adjustments such as introducing weather compensation controls to actively mitigate heat build up
Automated night-time purge ventilation to flush out daytime heat build-up
Adjusting internal gains (e.g., transitioning to low-heat LED lighting and optimised controls)
Roof optimisation such as reflective roof coatings to minimise thermal absorption
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Overheating mitigation and energy efficiency go hand-in-hand. Simply installing bigger cooling systems can hurt your EPC rating and conflict with Net Zero targets. By prioritising passive thermal resilience first, we reduce overall energy demand, helping you satisfy MEES requirements, achieve Net Zero pathways, such as CRREM, and improve EPC ratings without over-spending on mechanical equipment.
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The earlier, the better. Assessing thermal comfort during concept or early RIBA stages allows passive measures (like window specification, shading, and massing) to be designed in at minimal cost. However, for existing operational assets undergoing capital expenditure planning, an assessment provides a clear roadmap for cost-effective, targeted and high-impact retrofits.
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It is a rapidly escalating issue driven by two factors: stricter energy efficiency targets and hotter UK summers.
For decades, UK commercial buildings were built to keep winter heat in using heavy insulation and airtight facades. Today, that trapped heat, combined with intense urban heat island effects, higher glass ratios, and frequent heatwaves, creates severe summer overheating risks.
While residential developments face mandatory limits under Building Regulations Part O, commercial real estate faces a financial and operational challenge:
Occupant Health & Productivity: High internal temperatures directly trigger tenant complaints, reduce staff focus, and violate workplace health and safety expectations.
Energy Costs & Grid Capacity: Attempting to solve overheating solely with emergency air conditioning drives up energy bills, risks tripping building power capacity, and harms carbon ratings.
Asset Obsolescence: Institutional investors and corporate occupiers are increasingly screening properties for physical climate resilience. Buildings that suffer from uncontrolled summer heat risk becoming unsellable or unlettable ‘stranded assets.
Proactive overheating mitigation ensures your property stays operationally viable, energy-efficient, and attractive to premium corporate tenants as the UK climate shifts.
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It is a dynamic thermal simulation that tests your building’s physical performance against future weather scenarios rather than past climate data. Using Met Office UKCP18 datasets for the 2030s and 2050s, we ensure your building’s envelope and mechanical systems remain resilient throughout a standard 10- to 15-year lease cycle, preventing early obsolescence and maintaining tenant satisfaction as summer heatwaves become more frequent.
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HollenPlus is chartered surveyor led. We combine advanced Level 5 DSM thermal modelling with practical commercial real estate expertise. We don't just give you a pass/fail report, we deliver actionable, value-accretive overheating solutions that protect capital value, lower operational risks, and fit your broader asset management goals.
Contact our Chartered Surveying team today to discuss a CIBSE TM52 thermal assessment and low-CAPEX overheating strategy for your asset or portfolio.
