How we used SBEM modelling to guide the refurbishment of two adjacent industrial workshop units, achieving Band C with a clear pathway to Band B through targeted insulation and efficient heating systems.
Energy Performance Direct was instructed to carry out SBEM modelling for two adjacent industrial workshop units near Exeter undergoing refurbishment. Each unit comprises approximately 185.7 square metres of useful floor area, with ground floor workshop space and first floor office accommodation.
The client required draft EPCs modelling the intended improvements to confirm the achievable ratings before committing to the refurbishment specification. This is a practical and cost-effective approach: by running the SBEM calculations in advance, the client could confirm that the proposed works would achieve their target rating and identify any additional measures needed to reach a higher band.
Although the two units are structurally very similar, their differing orientations mean solar gains affect each building differently, producing slightly different EPC ratings despite near-identical specifications. This is a common occurrence with adjacent industrial units and demonstrates why each building requires its own individual assessment.
D72
Baseline
C72
After Refurb
B41
With Additional Measures
D72
Baseline
C68
After Refurb
B38
With Additional Measures
The 4-point difference between units is caused by orientation and solar impact. This demonstrates why each building requires individual SBEM assessment even when construction is identical.
185.7
Floor Area (sq m each)
24.44
kgCO2/m2/yr BER
261.16
kWh/m2/yr Primary
The client provided their intended refurbishment specification, which we entered into the SBEM model to calculate the achievable ratings. The following improvements were modelled as the baseline refurbishment package:
With the baseline refurbishment achieving Band C, the client asked what additional measures would bring both units to Band B. Our SBEM modelling identified two straightforward improvements that together deliver the step-change needed.
Achieve a U-value of 0.42 W/m2K. This requires approximately 100mm of mineral wool insulation above the suspended ceiling, a relatively low-cost measure that delivers significant improvement in the SBEM model.
Weather compensation adjusts heating output based on external temperature, reducing energy consumption. This is often a low-cost addition when specifying new AC systems and delivers meaningful benefit in the SBEM calculation.
These two measures alone bring the first unit to B41 and the second unit to B38.
Each of these measures would further improve the rating. Combining several would push towards Band A.
The baseline EPC assessment identified several long-payback recommendations. While none offered short or medium-term payback on their own, their combined impact is significant when pursuing higher ratings:
Introduce cavity wall insulation to uninsulated external wall cavities
Install secondary glazing or replace high U-value windows
Add weather compensation controls to heating system
Install or improve loft insulation in poorly insulated roof spaces
Consider installing solar water heating
Pre-refurbishment SBEM modelling allows clients to confirm achievable EPC ratings before committing to a specification, avoiding costly mistakes and ensuring the desired band is reached.
Identical buildings can achieve different EPC ratings due to orientation and solar impact. Each unit requires its own individual SBEM assessment even when construction specifications are the same.
Efficient LED lighting with high luminous efficacy (100 lmn/W) and proper controls contributes significantly to achieving good ratings in workshop and office environments.
The step from Band C to Band B can often be achieved through relatively modest additional measures such as ceiling insulation and weather compensation controls, without major structural changes.
AC systems with a COP of 3.5 or better, combined with local time and temperature controls, are highly effective for first floor office spaces above unheated workshop areas.
This advice is impartial and independent of any installers or specific products. We always recommend obtaining 3 to 5 like-for-like quotes to get an accurate idea of installation costs.
Light industrial and trade premises
How commercial EPC ratings are calculated
Minimum energy efficiency standards guide
All industrial and warehouse assessments
Devon industrial EPC assessments
793.5 sq m G-to-A improvement roadmap
Our accredited assessors can model your intended improvements before work begins, confirming achievable ratings and identifying the most cost-effective route to your target band.