Where do the EPC assumptions come from?
EPC Improvements calculator for Landlords
EPC Improvement Calculator, plan the cheapest path to EPC C
Energy upgrades pay twice through lower bills and stronger tenant appeal. The August EPC Improvement Calculator estimates the lowest-cost route from your current EPC band to C, using typical UK prices and uplift assumptions for common measures. Choose the property size, select your current band, and optionally model finance. We’ll sort measures by best value (£ per EPC point), estimate total upgrade cost, monthly finance payments, and a simple payback period. Ready to try August?
Costs and uplifts are indicative, based on UK market averages. Always obtain a professional survey/EPC assessment and itemised quotes before committing.
How this calculator works and what makes it different
Property size proxy - Number of bedrooms scales material and labour ranges (e.g. insulation coverage).
Current EPC to target C - You can start from G / F / E / D; we plan the steps to reach C.
Finance modelling - Pick a 1, 5 or 10-year term and an interest rate to see estimated monthly cost.
Prioritised measures - We order upgrades by £ per EPC point uplift so the cheapest gains appear first.
Payback view - A simple estimate from typical bill savings per measure vs cost (useful for budgeting, not a guarantee).
Actionable list - The results table mirrors your UI: Include, Measure, Estimated cost, Assumed uplift (pts), £/point.
Remember to maintain photos, quotes and warranties to each measure, these Documents can be uploaded to August. Also schedule reminders (e.g. EICR, boiler service, alarm tests).
Typical upgrade measures and why they help
The exact set depends on the property, but most rental homes reach C with a mix of fabric first, controls, and efficient systems:
Loft/roof insulation (to ~270–300mm) - Often the best £/point gain this reduces heat loss significantly.
Draught-proofing & basic fabric repairs - Cheap wins (letterboxes, floorboard gaps, chimneys, seals).
Cavity-wall insulation (if suitable) or internal/external wall insulation for solid walls.
Cylinder jacket & pipe insulation - Low cost, fast payback in homes with hot-water cylinders.
Heating controls - Programmer + room thermostat + TRVs, smart thermostats where appropriate.
Low-energy lighting (LED) - Small uplift, tiny cost—always include.
Floor insulation (suspended timber floors) - often found in older housing stock.
High-performance glazing/secondary glazing - Improves comfort and sound reduction which is useful near busy roads, but model cost carefully.
Efficient boiler or low-carbon system - use manufacturer efficiencies and pair with good controls.
Solar PV (with immersion diverter) or heat-pump readiness - property-specific and can move the dial when fabric is already good.
The calculator weights these by estimated uplift and size adjusted cost so you can see which steps move you fastest toward C.
Worked example of an EPC improvement
1-bed flat, current E, target C
Loan term: 5 years; rate: 5.0%
The tool might propose, in order of value:
Loft top-up to 300mm → +6–8 pts (low cost)
Draught proofing & LED throughout → +2–3 pts
Programmer/room stat/TRVs → +3–4 pts
Cylinder jacket and pipe insulation → +2 pts
Secondary glazing to single-glazed windows → +2–4 pts
Estimated total improvement cost - shown in Results
Estimated monthly finance - shown in Results (5-year, 5.0%)
Estimated payback - shown in Results, based on typical bill savings
If you still fall short of C after the cheapest steps, the table will show higher-cost options (e.g. wall insulation or system upgrades) so you can decide where to stop.
Finance and payback
Monthly finance = cost, term and rate you enter (interest-only or amortising per our assumptions). Use it to sense check affordability.
Payback compares typical bill savings to upfront cost. It is a planning guide only and actual savings vary with usage, tariffs and property condition.
Grants or ECO-style schemes can shorten payback.
Practical tips that protect returns
Do fabric first - Insulation and draught-proofing often deliver the cheapest EPC uplift and the best tenant comfort.
Fix the small gaps - Letterbox brushes, door seals and floor gaps are low-cost wins your EPC assessor will notice.
Pair systems with controls - A decent boiler wastes energy without proper zoning/TRVs.
Time upgrades with renewals - Coordinate works with voids to minimise lost rent.
Collect documents - Upload installer certifications, warranties and product specs into August. You’ll need them at sale, remortgage or licensing.
How to use the August EPC Improvement Calculator
Select number of bedrooms and your current EPC band (G/F/E/D).
Choose a loan term and interest rate if you want to model monthly cost.
Click Calculate to see:
Path (e.g., “From E to C”), Total improvement cost, Monthly finance, Payback,
A ranked list of measures with estimated cost, uplift and £/point.
Tick Include beside the measures you plan to do.
Disclaimer
The EPC Improvement Calculator is provided for general information and research purposes only. While it uses common UK cost benchmarks and simplified assumptions about EPC uplifts, we cannot guarantee that all calculations are complete, up to date, or accurate for every property or circumstance.
This tool is not a substitute for official EPC guidance, Standard Assessment Procedure (SAP) and Reduced Data Standard Assessment Procedure (RdSAP) assessments, or professional advice. Results are indicative only and may differ from outcomes following a qualified survey, local pricing, or lender terms.
We accept no liability for decisions made based on information provided by this tool. Always obtain independent surveys, quotes, and financial advice before committing to any works or finance.
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