How Environmental Assessments Add Credits to Your BREEAM Rating
Getting planning approval means demonstrating you've properly addressed flood risk. We prepare professional Flood Risk Assessments (FRAs) that satisfy the Environment Agency, Lead Local Flood Authorities, and local planning policy—helping your application progress without delay.
Too many planning applications stall because the flood risk assessment doesn't adequately address the key concerns, or fails to properly evaluate all flood sources. Our FRAs identify, evaluate and propose appropriate mitigation for all potential flood mechanisms, ensuring your development site meets national and local planning requirements whilst protecting future occupants.
We work with homeowners, developers, architects, planning consultants, and civil engineering practices—delivering policy-compliant assessments on time and to budget.
Flood Risk Assessment and BREEAM Credits
The flood risk assessment carries significant weight in BREEAM, worth up to 2 credits in commercial schemes and up to 19 credits in residential assessments. The approach varies depending on your flood zone classification, but there's credit potential regardless of location.
Low Flood Risk Sites (Flood Zone 1)
Sites in Flood Zone 1 get the straightforward route. You need a site-specific flood risk assessment confirming low annual probability of flooding from all sources – that means fluvial, pluvial, groundwater, and sewer flooding, not just river flooding. The FRA needs to account for climate change impacts over the development's lifetime.
For residential schemes under BREEAM UK New Construction: Residential Version 6.1, this alone secures all 19 credits available under the flood risk issue. That's a substantial credit allocation for what's essentially demonstrating you've picked a sensible location and done proper due diligence.
Commercial schemes under BREEAM UK New Construction 2018 get 2 credits for low flood risk, which then allows focus on maximising the surface water run-off credits.
Medium and High Flood Risk Sites (Flood Zones 2 and 3)
Higher risk sites need more work but can still achieve credits through flood resilience design. The options are either raising finished floor levels 600mm above design flood level, or implementing comprehensive flood resistance and resilience measures following BS 8533:2017.
Residential developments in Flood Zones 2 or 3 can achieve 17 credits (rather than 19) by demonstrating proper resilience measures. This includes flood-resistant materials, protected services routing, and consideration of access/egress during flood events.
The key difference from planning policy compliance is that BREEAM wants to see specific design responses: which materials you're using, how services are protected, what happens to mechanical plant during flooding. Generic statements about "following EA guidance" won't secure credits.
What BREEAM Actually Requires from Your FRA
The flood risk assessment needs to be site-specific – generic mapping references won't cut it. You need assessment of all flood sources, climate change allowances (typically +40% for peak river flows for 2080s), and clear identification of design flood levels.
For residential schemes, flood risk information must be communicated to purchasers before they decide to buy. This means your FRA findings need translating into something accessible in the sales process.
Sustainable Drainage Systems and Run-Off Credits
Surface water management offers another substantial credit opportunity: 2 credits in commercial schemes, or up to 14 credits in residential Version 6.1. The assessment focuses on both rate and volume of run-off, with higher credits for more sophisticated SuDS approaches.
Run-Off Rate Requirements
For brownfield sites, you need a 30% improvement in peak run-off rates compared to pre-development conditions. That's 30% reduction at both 1-year and 100-year storm events, calculated at each discharge point.
Greenfield sites must maintain pre-development rates – essentially keeping run-off at greenfield rates post-development. With climate change allowances, that typically means significant attenuation storage.
The calculations need doing properly. BREEAM expects hydraulic modelling following CIRIA SuDS Manual C753 methodology, with climate change factors applied to post-development scenarios only. If you're claiming 5l/s minimum discharge to prevent blockage, you need to justify it.
SuDS Hierarchy and BREEAM Credits
BREEAM rewards following the SuDS hierarchy: infiltration first, then attenuation, then controlled discharge as a last resort. You need documented justification for why you can't move up the hierarchy.
On contaminated sites, you can't use infiltration without remediation, but that needs demonstrating through site investigation. On clay soils, infiltration testing must show it's genuinely not viable rather than just being inconvenient.
Source control measures – permeable paving, green roofs, rain gardens – score well because they manage water where it falls. Saying you'll handle everything through an underground tank misses the point BREEAM's trying to make about sustainable drainage.
Water Quality Credits
There's 1 additional credit (3 credits in residential schemes) for water quality treatment. This means specifying appropriate SuDS treatment trains: typically 2-3 treatment stages before discharge to watercourses.
High-risk areas – car parks, delivery yards, refuelling areas – need petrol interceptors or equivalent. Chemical storage requires emergency shut-off valves. These aren't just planning requirements; they're specific BREEAM criteria.
The first 5mm of rainfall should be prevented from leaving the site untreated. On very constrained sites where this proves impossible, you need professional justification from a suitably qualified consultant explaining why and demonstrating you've got as close as practically achievable.
Maintenance Requirements for Credits
2 credits depend on maintenance agreements being in place. That means documented arrangements for ownership, operation and maintenance of all SuDS features over the design life of the development.
For residential schemes where features sit in private gardens, you need homeowner guidance. For communal areas, management company specifications. For adopted highways, Section 38/Section 104 agreements with commuted sums.
Air Quality and NOx Emissions
The air quality issue focuses on NOx emissions from heating systems, worth up to 3 credits in most BREEAM schemes. It's straightforward in principle but requires attention during M&E specification.
Emission Thresholds
Credits are tiered based on NOx emissions measured at 0% excess oxygen:
-
1 credit: ≤100 mg/kWh (NOx Class 4 boilers)
-
2 credits: ≤70 mg/kWh (NOx Class 5)
-
3 credits: ≤40 mg/kWh (NOx Class 6)
Heat pumps and other non-combustion systems get credits by default since they have zero direct emissions. Biomass systems struggle here despite being renewable – they can produce significant NOx and typically can't achieve credits under this issue, though they score in the energy section.
What Counts Towards Assessment
All heating and hot water systems serving the building need assessing. Backup boilers only escape assessment if they're excluded from SAP/SBEM calculations for Ene 01. If they're contributing to your energy model, they need meeting the emission thresholds.
For multiple systems in one building, credits are awarded based on the worst performer. You can't offset a high-emission CHP with low-emission boilers elsewhere.
District heating connections are treated as zero direct emissions for the building, but the plant itself needs assessment if you're claiming credits for the heat network under a separate BREEAM assessment.
Evidence Requirements
You need manufacturer's emissions data following the Ecodesign Directive 2009/125/EC labelling requirements. This should quote mg/kWh at a specified excess oxygen level. If it's quoted at 3% or 6% excess oxygen, apply the conversion factors to get the 0% basis BREEAM requires.
Climate Resilience and Future-Proofing
Whilst not a separate BREEAM issue, climate resilience runs through multiple credits and increasingly affects Excellent and Outstanding ratings.
Climate Change Allowances
All flood risk and surface water calculations must include climate change allowances. For most of England, that's +40% peak river flows and +20-40% peak rainfall intensity depending on development lifetime and risk tolerance.
These aren't optional additions – they're mandatory for achieving any BREEAM credits in flood risk or surface water issues. BREEAM expects to see the climate change factors explicitly stated in your calculations.
Adaptation Measures
Higher BREEAM ratings increasingly require demonstrating how the development adapts to changing conditions: overheating risk, water scarcity, extreme weather events. Flood resilience and sustainable drainage directly address these concerns.
Green infrastructure – green roofs, rain gardens, swales – scores well because it tackles multiple climate risks simultaneously: reducing flood risk, managing urban heat island effect, improving air quality, and supporting biodiversity.
Strategic Approach to Maximising Credits
Early Stage Planning
The biggest mistake is treating these assessments as planning compliance exercises done at the last minute. BREEAM requires design evidence – you need to show decisions being made and alternatives being considered, not just retrospective justification.
Get your flood risk assessment done at feasibility stage. It informs site layout, finished floor levels, access arrangements. Making these decisions early means they're embedded in the design rather than awkward retrofits.
Similarly, SuDS should influence the landscape strategy from the outset. Integrated design where drainage features provide amenity value and biodiversity benefit scores better than engineered solutions tacked on to satisfy discharge requirements.
Coordinated Assessment
These issues don't sit in isolation. Your flood risk assessment informs surface water strategy. Climate change factors apply to both. Air quality affects ventilation strategy and energy systems, which then feed into overheating assessments.
Using one consultant for flood risk, SuDS, and air quality work ensures consistent climate change assumptions and integrated solutions. It also makes the BREEAM submission more coherent when the same methodology runs through multiple issues.
Cost-Effective Credits
The pollution category offers some of the most cost-effective credits in BREEAM. A flood risk assessment is typically required for planning anyway. Specifying NOx Class 6 boilers rather than Class 4 might cost an extra £50-100 per boiler. Designing SuDS properly from the start costs less than retrofitting attenuation tanks later.
Compare this to chasing energy credits through expensive technology or pursuing materials credits through certified supply chains, and the return on investment becomes clear.
Common Issues and How to Avoid Them
Brownfield Run-Off Rates
The 30% improvement for brownfield sites catches people out. It's not 30% below greenfield rates; it's 30% below whatever was there before. If you're redeveloping a car park with 100% run-off, greenfield rates might be a 90% reduction, not 30%.
For derelict sites (vacant over 5 years), you need a drainage consultant to assess the previous network and establish probable historic flow rates through hydraulic modelling. Without this, BREEAM treats the site as greenfield.
Climate Change Factor Confusion
Climate change allowances apply to post-development calculations only, not pre-development baselines. This is logical – you're assessing future flood risk, not historic conditions – but it's frequently got wrong in calculations.
The specific percentages vary by location, development type, and assessment lifetime. Don't assume +40% applies everywhere; check the Environment Agency guidance for your catchment.
Off-Site Discharge Limitations
BREEAM expects you to minimise off-site discharge, not just control the rate. If your local authority or sewerage undertaker accepts a specific discharge rate, that doesn't automatically satisfy BREEAM requirements – you still need to demonstrate you've followed the SuDS hierarchy and minimised volumes.
Maintenance Agreement Timing
The 2 SuDS maintenance credits require agreements at final BREEAM assessment, not just design stage intentions. That means management companies, adoption agreements, and commuted sums need finalising before practical completion.
BREEAM Versions and Regional Variations. UK New Construction 2018 vs Version 6.1 Residential
UK New Construction 2018 vs Version 6.1 Residential
The residential scheme weights these issues differently, with flood risk potentially worth 19 credits compared to 2 credits in commercial schemes. Surface water management is worth up to 19 credits in residential versus 5 in commercial.
Residential schemes also require homeowner information for several credits – summarising flood risk, drainage systems, and maintenance requirements in accessible language for residents.
Scotland, Wales and Northern Ireland
Whilst the credit structure is consistent, the reference standards vary. Wales uses Flood Consequence Assessments rather than FRAs. Scotland has different planning guidance.
Northern Ireland references different regulatory frameworks.
The fundamental principles remain the same, but evidence requirements need adapting to local planning policy and statutory consultees.
BREEAM International and Version 7 Updates
BREEAM International New Construction Version 6.0 has similar credit structures, adapted for local flood risk definitions and drainage standards in different countries.
Version 7, being rolled out for UK market, maintains these pollution credits but with increased minimum standards for Excellent and Outstanding ratings. The fundamentals don't change, but the bar for higher ratings is rising.
When to Bring in Specialists
Whilst architects and M&E consultants handle much of the BREEAM process, the pollution category generally needs specialists. You need a suitably qualified flood risk consultant, typically a chartered engineer or equivalent with specific drainage experience.
For SuDS, BREEAM requires an "appropriately qualified professional" – someone capable of hydraulic design following CIRIA C753, understanding infiltration testing, and integrating drainage with landscape design. This isn't a role for general civils engineers without drainage expertise.
The investment in proper specialists typically pays for itself through avoided abortive work. Getting drainage wrong means redesigning schemes; specifying wrong boilers means replacing plant. Better to get it right first time.
Planning Integration
These assessments serve dual purpose: BREEAM credits and planning compliance. Your flood risk assessment satisfies NPPF requirements. Your SuDS strategy addresses local plan policies and statutory consultee comments. Air quality assessment may be required for planning in AQMAs.
The difference is that planning sets minimum standards whilst BREEAM rewards going further. A site-specific FRA demonstrating compliance with EA guidance gets you planning permission. Demonstrating 600mm freeboard and flood-resistant detailing gets you BREEAM credits.
Smart developers commission assessments that satisfy both requirements simultaneously rather than duplicating effort.
Frequently Asked Questions
Do I need a flood risk assessment if I'm in Flood Zone 1?
Yes, BREEAM requires a site-specific assessment even for low-risk sites. It needs to confirm low flood risk from all sources and include climate change allowances. A simple desk study referencing EA mapping won't secure credits – you need a professional assessment considering surface water, groundwater, and potential flow paths, not just fluvial flooding.
Can I achieve the SuDS credits with a standard attenuation tank?
Possibly, but it's not the approach BREEAM rewards. You'll get rate-control credits if your tank provides the required 30% improvement (brownfield) or maintains greenfield rates. But higher credits require demonstrating you've followed the SuDS hierarchy – infiltration, then surface features, then tanks as a last resort. You need documented justification for why surface solutions aren't viable on your site.
What if my mechanical engineer has already specified standard boilers?
Switching from NOx Class 4 to Class 6 boilers is typically a product swap rather than a design change. The cost difference is modest – perhaps £50-100 per unit – and saves three BREEAM credits worth of effort elsewhere. It's usually the easiest specification change you can make to improve your rating.
How do heat pumps affect the air quality credits?
Non-combustion systems like heat pumps get air quality credits by default since they have zero direct emissions. This is one reason heat pumps score well in BREEAM – they contribute to energy credits and pollution credits simultaneously. The installation costs more, but the credit return is substantial.
What are the Sequential Test and Exception Test?
Are maintenance agreements really necessary for the SuDS credits?
Yes, 2 credits specifically require documented maintenance arrangements before final certification. For residential schemes, this means homeowner guidance for private SuDS features, management company specs for communal areas, or adoption agreements for highway drainage. It's not negotiable – no agreements means no credits, regardless of how good your SuDS design is.
Can I use our planning FRA for BREEAM assessment?
Usually, yes. The planning FRA should contain everything BREEAM requires: site-specific assessment, all flood sources, climate change allowances, design flood levels. You might need supplementary information on resilience measures or finished floor levels, but the base assessment serves both purposes. Just ensure your FRA consultant knows you need BREEAM evidence as well as planning compliance.
What happens if the statutory consultee requires a different discharge rate than BREEAM?
BREEAM accepts statutory requirements that differ from the standard benchmarks, but you need documentary evidence. If the sewerage undertaker or EA specifies a particular rate, provide their formal correspondence or approval. BREEAM then assesses against that requirement rather than standard thresholds. All other criteria still apply – you still need appropriate SuDS treatment, maintenance agreements, and climate change allowances.
Do I need separate flood risk assessments for planning and BREEAM?
No, one properly prepared assessment serves both. Commission it as a site-specific FRA meeting NPPF requirements and BREEAM criteria simultaneously. Make sure your consultant knows you need BREEAM certification so they include the specific information BREEAM assessors require: clear flood zone confirmation, design flood levels with climate change, and details of proposed resilience measures.
Can rainwater harvesting contribute to the run-off credits?
Yes, rainwater harvesting systems reduce run-off volumes and can contribute to achieving the discharge rate requirements. However, they need designing to BS EN 16941-1:2018 standards. Also, your flood exceedance routes must be sized assuming the rainwater system is unavailable – you can't rely on harvesting tanks for flood protection since they might be full when the storm arrives.
What's the difference between flood resistance and flood resilience?
Flood resistance means keeping water out – sealed doors, airbrick covers, waterproof membranes. Flood resilience means designing so the building recovers quickly when water does get in – concrete floors instead of timber, tile rather than plasterboard, services above flood level. BREEAM rewards comprehensive strategies addressing both, following BS 8533:2017 guidance. Simply raising floor levels gives you resistance; proper material selection and service design gives you resilience.
How detailed do the hydraulic calculations need to be?
BREEAM expects professional standard drainage design using recognised modelling software – MicroDrainage, InfoWorks, or similar. Your calculations need showing pre-development run-off, post-development run-off with climate change, attenuation storage volumes, and discharge rates at 1-year and 100-year return periods. Hand calculations won't satisfy the requirements for projects beyond simple single dwellings.
Can I claim credits for existing drainage if we're doing a refurbishment?
Only if the existing systems are appropriately sized for any additional hard surfaces you're creating, and they're properly maintained to provide the required capacity. You need evidence of the system's capability and condition. For most refurbishments adding significant hard standing, you'll need additional SuDS features.
What counts as a "suitably qualified professional" for SuDS design?
BREEAM expects someone capable of hydraulic design following CIRIA C753, typically a chartered engineer with drainage experience, or a landscape architect with specialist SuDS training. They need demonstrating knowledge of infiltration testing, treatment train design, and exceedance flow paths. Professional membership (ICE, CIWEM, LI) provides evidence of competence, though the specific qualifications matter less than demonstrated expertise in sustainable drainage design.
Are there any credits for managing construction phase flood risk?
Not directly under these issues. Construction phase flood risk affects site safety and environmental management but doesn't score in the pollution category. However, proper flood risk assessment informs your construction phase planning and may contribute to health and safety credits elsewhere in the assessment.
How do I demonstrate compliance if my development discharges directly to the sea?
Direct discharge to tidal estuaries or the sea can satisfy the run-off criteria by default, achieving 14 credits without attenuation measures. However, drainage pipes must only carry run-off from your site and must not cross privately owned land before reaching the sea. You need confirming the discharge point meets these conditions. Water quality credits still apply even for coastal discharges.
Getting Started with Your BREEAM Assessment
The pollution category offers straightforward credit potential if you approach it properly. Start early, involve specialists where needed, and integrate these assessments into your design development rather than treating them as compliance exercises.
Get your flood risk assessment commissioned at feasibility stage. It affects site layout decisions that become expensive to change later. Work with your drainage consultant to develop integrated SuDS that provide amenity and biodiversity benefits alongside flood management. Coordinate with your mechanical engineer to specify low-NOx heating systems from the outset.
These aren't difficult credits to achieve, but they do require proper professional input and evidence. Done well, they can make a substantial difference to your overall BREEAM rating without the eye-watering costs associated with some other credit categories.
Expert BREEAM Assessment Support
We provide specialist flood risk assessment, SuDS design, and air quality assessment services specifically for BREEAM projects. With CIWEM qualification and extensive experience of BREEAM submissions, we understand exactly what evidence assessors need to award credits.
Our assessments satisfy both planning requirements and BREEAM criteria simultaneously, avoiding duplication of effort and ensuring your reports contain the specific information required for certification. We work alongside your design team from early stages to embed credit-winning strategies into the development.
Services include:
-
Site-specific flood risk assessments for all BREEAM schemes
-
SuDS design and hydraulic modelling following CIRIA C753
-
Air quality assessments including construction dust and air quality neutral calculations
-
Climate resilience strategies and adaptation planning
-
BREEAM evidence preparation and assessor liaison
Based in London and operating throughout UK, we provide rapid turnaround for projects requiring BREEAM assessment.
Professional indemnity insurance exceeds £1 million, and we maintain robust quality assurance procedures for all technical submissions.
Contact us today to discuss your BREEAM requirements
Early engagement makes the difference between scrambling for credits late in the process and having a clear strategy from the outset. Get in touch to see how proper environmental assessment can strengthen your BREEAM submission.