Existing Commercial Building Energy Assessments
L2B SBEM Calculations London
Professional SBEM calculations for alterations, extensions, refurbishments and changes of use to existing commercial and non-domestic buildings throughout London and Greater London.
L2B SBEM Assessments in London
If you are altering, extending or converting an existing commercial building in London, an L2B SBEM Calculation may be required to demonstrate compliance with Part L of the Building Regulations.
One Stop Consult provides accurate, fully compliant SBEM assessments for developers, architects, contractors and property owners working on existing non-domestic buildings.
Our assessors support projects ranging from office refurbishments and warehouse extensions to retail fit-outs, healthcare facilities, educational buildings and commercial changes of use.
L2B SBEM Calculations Across London and Greater London
We support projects throughout Central London, Westminster, Kensington, Chelsea, Camden, Islington, Southwark, Lambeth, Greenwich, Stratford, Wimbledon and Ealing.
Nearby coverage also includes Croydon, Bromley, Barnet, Enfield, Harrow, Hounslow, Romford and surrounding Greater London areas.
What Is an L2B SBEM Calculation?
An L2B SBEM Calculation is an energy assessment used to demonstrate compliance with Part L where qualifying works are carried out to an existing commercial or non-domestic building.
Unlike L2A, which applies to new non-domestic buildings, L2B is generally used for significant alterations, extensions, refurbishments and material changes of use.
The assessment evaluates the proposed fabric, heating, cooling, ventilation, lighting and other building services against the relevant energy-efficiency requirements.
L2B SBEM Services
What Our London Service Can Include
01
Design-Stage SBEM Calculations
Early assessment of the proposed works before construction or refurbishment begins.
02
Extension Assessments
SBEM calculations for suitable commercial and non-domestic building extensions.
03
Alteration and Refurbishment Assessments
Energy assessments for major alterations, fit-outs and refurbishment projects.
04
Part L Compliance Reports
Clear documentation prepared for submission to Building Control.
05
BRUKL Reports
Building Regulations compliance reports generated from the completed SBEM model.
06
Commercial EPCs
EPC preparation following completion where required for the project and compliance route.
07
HVAC Energy Assessments
Review of heating, cooling and ventilation systems within the proposed works.
08
Lighting Compliance Assessments
Assessment of lighting efficiency, controls and system power.
09
Technical Design Support
Practical advice where the proposed design does not initially achieve compliance.
Typical London Projects
Existing Buildings We Commonly Assess
What Does the Assessment Review?
The assessor reviews the existing and proposed building fabric and services affected by the works.
Accurate architectural and M&E information helps confirm the correct assessment scope and identify practical routes to compliance.
Existing and proposed walls
Roofs, floors and glazing
Heating and cooling systems
Mechanical ventilation
Lighting and controls
Hot-water systems
Air permeability where relevant
Renewable technologies
SBEM Calculations for Commercial Extensions
Significant extensions to non-domestic buildings may require an L2B assessment to demonstrate that the proposed fabric and services meet the relevant Part L standards.
The assessment should be completed early enough for insulation, glazing, HVAC and lighting decisions to be incorporated before work begins.
Where the extension interacts with existing building systems, accurate information about the retained services is important.
Refurbishments, Fit-Outs and Changes of Use
Commercial refurbishments can involve new internal layouts, replacement services, upgraded fabric and changes to how the building is occupied.
The assessor reviews the proposed works and models the relevant building zones, systems and construction elements.
A commercial EPC may also be needed at completion, depending on the nature of the project and applicable requirements.
Improving Compliance
Practical Measures the Assessor May Review
Where the initial model does not satisfy Part L, practical improvements can be considered with the design team.
Improved Fabric Performance
Better wall, roof, floor or glazing performance can reduce heat loss and energy demand.
Efficient HVAC Systems
More efficient heating, cooling and ventilation equipment can improve the model result.
Efficient Lighting
Lower-energy fittings and suitable controls can reduce predicted electrical consumption.
Improved Controls
Zoning, time controls and demand-led operation can improve system performance.
Reduced Air Leakage
Appropriate airtightness improvements may support compliance where relevant to the works.
Renewable Technologies
Solar PV or other suitable technologies may support the compliance strategy.
Our L2B SBEM Assessment Process
We coordinate the assessment from the initial project review through to the completed compliance report.
Send us the existing and proposed drawings.
Provide the construction and M&E specifications.
The assessor confirms the appropriate L2B scope.
The design-stage SBEM model is prepared.
Any required compliance improvements are identified.
The assessment is updated if the design changes.
Final reporting and EPC support are provided where applicable.
1
Project Review
Review the existing building, proposed works and Building Control requirement.
2
Information Check
Confirm the fabric, HVAC, ventilation, lighting and hot-water information.
3
Design-Stage SBEM
Model the proposed works and assess Part L compliance.
4
Design Advice
Recommend practical improvements where required.
5
Final Documentation
Issue the BRUKL report and EPC support where applicable.
Why Choose One Stop Consult?
Our assessors work on commercial refurbishments, extensions, fit-outs and changes of use across London and nationwide.
We provide clear calculations, practical advice and responsive support throughout the design and approval process.
Experienced SBEM assessors
Fast turnaround times
Fixed competitive pricing
Current Part L compliance support
Existing-building expertise
Practical M&E design advice
Building Control support
London and nationwide coverage
Information Required for a Quotation
Provide the full London project address, building use, approximate floor area and description of works.
Please upload the existing and proposed architectural drawings, construction specification and available M&E information.
HVAC, ventilation, lighting, hot-water and renewable-technology details should also be supplied where available.
Related London Services
Other Services Your Project May Require
Important L2B SBEM Information
L2B requirements depend on the project type, extent of works and Building Control compliance route. SBEM results rely on the accuracy of the existing and proposed architectural, construction and building-services information supplied.
Changes made during construction can affect compliance and should be referred back to the assessor. One Stop Consult provides consultancy and coordination support through experienced SBEM assessors.
Frequently Asked Questions
L2B SBEM Calculations London FAQs
What is an L2B SBEM Calculation?
It is an energy assessment used for qualifying alterations, extensions and changes to existing non-domestic buildings.
What is the difference between L2A and L2B?
L2A applies to new non-domestic buildings, while L2B applies to qualifying work involving existing non-domestic buildings.
When is an L2B assessment required?
It may be required for significant extensions, alterations, refurbishments or material changes of use to existing commercial buildings.
What information do you need?
Existing and proposed drawings, construction specifications, HVAC, ventilation, lighting and hot-water information are normally required.
Will I receive a commercial EPC?
Where applicable, a commercial EPC can be prepared following completion of the relevant assessment.
Can you help if the design does not comply?
Yes. The assessor can recommend practical improvements to the fabric, HVAC, lighting, controls or renewable systems.
Do shop fit-outs need SBEM calculations?
Some fit-outs and major alterations may require an L2B assessment, depending on the scope and Building Control requirements.
Do you cover all of London?
Yes. We provide L2B SBEM calculations throughout London, Greater London and the wider Greater London.
What information is needed for a quotation?
Provide the address, building use, floor area, description of works, drawings and available M&E information.
Request Your Free L2B SBEM Calculations Quote
Complete the form below with the London project address, building use, approximate floor area and description of works. Upload the existing and proposed drawings, construction specification and available HVAC, ventilation and lighting information so our team can review the requirement and provide an appropriate quotation.