Choosing the right energy improvements for your property involves a sequence of decisions, and each decision is more financially sound when it is based on numbers rather than general guidance. This page brings together fifteen free planning tools that cover the full sequence: identifying which improvements to prioritise, modelling the financial case for each one, and planning the timing relative to remortgages, sales, and grant deadlines.
Find your starting point
Not sure where to begin? The home energy upgrade sequencer takes your property type, construction era, and current EPC and produces a ranked priority list. If you want a single calculator that covers all improvement types with payback, stacking, loan, and grant modelling, the energy upgrade payback calculator does that in one tool.
Concerned about energy bills? The energy affordability calculator focuses on what proportion of household income goes on energy and which improvements reduce it most.
Landlord with multiple properties? Start with the MEES portfolio planner for the compliance picture across your portfolio before assessing any individual property.
Know what you want to model? Jump to heating and insulation, solar and EV, financing and timing, or property decisions.
Approaching a remortgage or sale? The financing tools model whether completing EPC works before your remortgage unlocks a rate reduction, and the property tools model whether improving the EPC before listing recovers its cost at sale.
All tools run in the browser and do not store or transmit any data you enter. All figures are illustrative estimates and should be treated as planning context rather than financial advice. For significant decisions such as a heat pump installation, a remortgage, or a property sale, professional advice from a qualified installer, mortgage broker, or estate agent is the right next step.
At a Glance
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If you do not yet have a clear list of priorities, start with the sequencer or the energy affordability calculator before reaching for specialist tools.
The home energy upgrade sequencer takes your property type, construction era, current EPC, and fuel type and produces a ranked list of improvements ordered by financial return per pound, with grant eligibility flagged automatically. The energy affordability calculator is the better starting point if your primary concern is the proportion of household income going on energy bills rather than improvement planning. Landlords with multiple properties should start with the MEES portfolio planner, which gives the compliance picture across the portfolio before any individual property is assessed in detail.
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For the heating system decision, model the boiler-versus-heat-pump comparison alongside the insulation case, since the two interact.
The boiler vs heat pump calculator runs a fifteen-year total cost comparison including the Boiler Upgrade Scheme grant (£7,500, or £9,000 for eligible off-gas-grid properties until March 2027). The insulation savings calculator compares loft, cavity wall, solid wall, and floor measures side by side with grant eligibility flagged. Although insulation is no longer a formal BUS eligibility condition, improving insulation before installing a heat pump remains best practice: a well-insulated home lets the heat pump run at lower flow temperatures, which improves efficiency and reduces running costs. The heat pump running cost calculator models the actual running cost for your property based on heat demand, SCOP, and tariff.
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Solar panels, battery storage, and EV home charging interact in ways that are not obvious, so model them together rather than separately.
The solar savings calculator estimates generation, bill savings, and Smart Export Guarantee income for a system sized to your roof orientation, shading, and self-consumption rate. The battery size calculator shows the financially optimal storage capacity for that system. The EV home charging optimiser shows how charging at home shifts the household’s daily energy profile and therefore changes the optimal battery size. Running the three in sequence produces a coherent system picture rather than three components considered in isolation.
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For households facing a financial event (loan application, remortgage, purchase, or sale), the financing and property tools model how energy efficiency interacts with those decisions.
The green mortgage EPC calculator models whether reaching EPC B before a remortgage delivers a rate reduction worth the improvement cost. The property running cost comparator shows the ten-year total cost of two competing properties including running costs and improvement works. The EPC before selling calculator and the remortgage timing calculator address the seller and remortgager respectively. The energy efficiency loan payback calculator and retrofit timeline planner support the borrowing-side and sequencing decisions.
Where to start
Understand your starting position
These tools help you understand where your property stands before committing to any specific improvement. Use them to identify priorities, assess the energy cost burden on household income, model all improvement types in one place, and (for landlords) map the compliance position across a portfolio.
Home energy upgrade sequencer
Which improvements should you prioritise? The sequencer ranks measures by financial return per pound for your property profile, with grant eligibility flagged.
All-in-oneEnergy upgrade payback calculator
Select improvements, enter your energy spend, and see payback periods with a stacking model that shows realistic combined savings. Includes loan toggle, carbon panel, and BUS grant deduction.
Energy affordabilityEnergy affordability calculator
What proportion of household income goes on energy bills? Which improvements reduce it most? Which support schemes may be available for your situation?
LandlordsLandlord MEES portfolio planner
Enter up to eight rental properties to see which are MEES-compliant, the improvement cost per property to reach EPC C, and the portfolio total.
Heating and insulation
Model heating and insulation decisions
Insulation and heating system decisions typically represent the largest single costs in a home energy improvement programme. These three tools model the financial case for each in detail, from comparing boiler and heat pump over fifteen years to showing all insulation types side by side with grant eligibility.
Insulation savings calculator
Loft, cavity wall, solid wall, and floor insulation compared side by side: costs, annual savings, EPC impact, grant eligibility, and the loan case for the net cost after grant.
HeatingBoiler vs heat pump calculator
Should you replace the boiler or install a heat pump? Models the fifteen-year total cost comparison including the BUS grant (£7,500, or £9,000 for off-gas-grid homes) and current fuel prices.
Heat pumpHeat pump running cost calculator
What will a heat pump actually cost to run in your home? Models annual running cost based on heat demand, SCOP, and electricity tariff, with seasonal variation.
Solar and EV
Model solar, battery storage, and EV charging
Solar panels, battery storage, and EV home charging interact with each other in ways that are not obvious. The EV charger changes the optimal battery size. The battery changes the financial case for solar. These three tools model each component and their interaction.
Solar panel savings calculator
Estimates annual generation, bill saving, and SEG income for your solar system based on roof orientation, shading, and household self-consumption rate. Includes monthly generation profile.
Battery storageSolar battery size calculator
What battery size is financially optimal for your solar system? Models daily surplus absorption, diminishing returns, and the impact of time-of-use tariffs on the battery case.
EV chargingEV home charging optimiser
Annual home vs public charging cost, home charger payback period (usually under a year), solar divert contribution, and whether the EV changes the optimal battery size for your solar system.
Financing and timing
Assess financing, timing, and mortgage impact
How you time and fund improvements significantly affects the total cost of the improvement programme. These tools model when loan interest is outweighed by energy savings, the optimal sequence and timing of works relative to financial events, and the mortgage interest saving from reaching EPC B.
Energy efficiency loan payback calculator
Borrowing for one upgrade? See the year cumulative energy savings overtake the total loan interest, with monthly repayment, breakeven year, and a year-by-year breakdown. Upgrade presets and grant quick-select included.
PlanningRetrofit timeline planner
Enter your upcoming remortgage, sale, or tenancy dates and the improvements you are planning to see the optimal schedule with dependency rules and timing risks flagged.
Green mortgageGreen mortgage EPC saving calculator
How much would reaching EPC B save in mortgage interest over the life of the deal? Models the rate reduction, improvement cost, and net position for your mortgage balance.
Property decisions
EPC and energy costs in property transactions
EPC ratings affect both the cost of owning a property and its sale price and mortgage accessibility. These three tools serve buyers comparing two properties, sellers deciding whether to improve before listing, and homeowners deciding whether to break a fixed rate now or wait.
Property running cost comparator
Comparing two properties to buy? Shows the ten-year total cost including energy running costs and improvement works, with the crossover year highlighted.
SellingEPC improvement before selling calculator
Is it worth improving the EPC before listing? Shows the improvement cost, indicative sale price uplift range from published research, and net position.
RemortgageRemortgage timing calculator
Break the fixed rate now or wait until it ends? Compares the ERC cost against the lower rate saving, with a second charge option for additional borrowing.
How These Tools Work Together
Each tool answers a specific question, but the questions are part of a broader decision sequence. Understanding how the tools connect helps you use them in the right order rather than in isolation.
The natural starting point for most households is the home energy upgrade sequencer, which takes your property type, construction era, current EPC, and fuel type and produces a ranked list of improvements ordered by financial return per pound spent. The sequencer applies dependency rules (for example, insulation before a heat pump, because a well-insulated home lets the heat pump run more efficiently at lower flow temperatures) and flags which improvements may qualify for grant funding through ECO4 (running until December 2026, with limited remaining capacity) or the Warm Homes Local Grant. This gives you a shortlist of two or three priority improvements rather than an overwhelming list of everything that could theoretically be done.
Once you have a shortlist, use the specialist tools to model each priority in detail. If insulation is the top priority, the insulation savings calculator shows all applicable types for your property side by side with costs, grant eligibility, and the loan case for any net cost. If a heating system change is in the picture, the boiler vs heat pump calculator models the fifteen-year comparison in full, including the Boiler Upgrade Scheme grant (£7,500, or £9,000 for eligible off-gas-grid properties from July 2026 to March 2027). If solar is under consideration, the solar savings calculator, battery size calculator, and EV charging optimiser should be used together: the interaction between them produces a combined system picture that is more useful than the three tools run in isolation.
Having established which improvements make financial sense and at what cost, the financing tools model how to fund them efficiently. The energy efficiency loan payback calculator shows when the energy saving outweighs the loan interest for each improvement. The green mortgage EPC calculator shows whether completing EPC improvements before a remortgage unlocks a rate reduction that materially changes the financing picture. The retrofit timeline planner brings timing and financing together: enter your remortgage or sale date and the improvements you have chosen, and it produces a phased schedule with dependency rules and timing risks shown against a visual calendar.
For households in a property transaction — buying, selling, or remortgaging — the property decision tools model the transaction-specific financial questions. The property running cost comparator is designed to be used during a property search, before an offer is made. The EPC before selling calculator is most useful three to six months before a planned listing date, when there is still time to complete improvement works and have a new EPC certificate issued. The remortgage timing calculator is best used four to six months before a fixed rate deal end, when the rate picture is clearer and there is still time to complete EPC improvements if the green mortgage angle justifies it.
Current government grants — September 2026/p>
Boiler Upgrade Scheme (BUS)
£7,500 toward an air source or ground source heat pump. £9,000 for eligible off-gas-grid properties (oil or LPG heating) from 21 July 2026 to 31 March 2027. No income test. MCS-certified installer applies on your behalf. Extended to 2030. Check eligibility on GOV.UK
ECO4
Free insulation and heating improvements for households on certain means-tested benefits. Runs until 31 December 2026, but most funding has already been allocated and new applications are limited. Applied for through energy suppliers. ECO4 on GOV.UK
Warm Homes Local Grant
Up to £15,000 for energy efficiency improvements for eligible low-income households in England. Delivered through local councils rather than energy suppliers. Check eligibility on GOV.UK
Availability, eligibility, and grant amounts are subject to change. The Great British Insulation Scheme (GBIS) closed on 31 March 2026. Always verify current grant eligibility on GOV.UK before relying on grant availability.
These tools are planning aids, not professional assessments. For insulation and heating improvements, a professional energy assessment of your property will produce more accurate costs and saving estimates than any calculator based on national averages. For mortgage decisions, a whole-of-market FCA-regulated mortgage broker is the appropriate source of advice. For property valuations, a local estate agent who knows your market will give a more accurate view of any EPC-related sale price premium than published research ranges. The tools here are designed to help you ask better questions of those professionals, not to replace them.
Related Guides
Guide
Home improvement loans for energy efficiency upgrades
Covers all the main energy efficiency improvements, their cost ranges, saving profiles, the loan types suited to each, and how to sequence borrowing across a multi-stage improvement programme.
Guide
Government grants vs home improvement loans
Covers ECO4, the Boiler Upgrade Scheme, and the Warm Homes Local Grant: eligibility conditions, how to apply, and how to combine grant funding with a loan for the balance.
Guide
How to build a realistic improvement budget before applying for finance, including how to phase works across multiple years, when to combine measures with a single contractor, and how to avoid overborrowing.
Tool
Home improvement ROI estimator
For improvements beyond energy efficiency — kitchen, bathroom, extension — the ROI estimator models the financial return in terms of property value uplift relative to cost. Use alongside the energy efficiency tools for a complete improvement picture.
Not sure what to look at next?
All of our home improvement loan guides and tools in one placeFrequently Asked Questions
Are these tools free to use?
Yes. All tools on this page are free to use with no registration, account, or personal information required. All calculations are performed in your browser using the inputs you enter. Nothing is stored on Squared Money’s servers, and no data is transmitted when you use any of the calculators. The tools are funded by Squared Money’s introducer service for home improvement loans: if you choose to check loan eligibility through the “Check eligibility” button, you will be directed to a separate loan enquiry process where information is handled in accordance with Squared Money’s privacy policy.
The tools are designed to be used repeatedly with different inputs as you refine your improvement plans. There is no limit on usage and no obligation to proceed to a loan enquiry after using any tool. The purpose of the calculators is to help you make better-informed decisions about home energy improvements, whether or not you ultimately borrow to fund them.
How accurate are the figures in these calculators?
All figures are illustrative estimates based on UK average data. They are useful for planning and for identifying which options are worth pursuing in detail, but they are not precise forecasts of what any specific improvement will cost or save for any specific property. The main sources of variation from actual figures are property size (the calculators use size bands rather than exact square meterage), local installer rates (which vary significantly by region and demand), and actual energy usage (which depends on occupancy, heating preferences, and tariff).
For decisions that involve significant sums — a heat pump installation, a remortgage, a property sale — treat the calculator outputs as a starting point for conversations with professionals rather than as final figures. A professional energy assessment, a mortgage broker consultation, or an estate agent’s valuation will produce more accurate and specific numbers for your property and circumstances. The tools are designed to help you arrive at those conversations better prepared, with the right questions identified in advance.
Which tool should I start with if I am completely new to energy improvements?
The home energy upgrade sequencer is designed as the starting point for most users. It asks for your property type, construction era, current EPC rating, current fuel type, and a rough budget range, and produces a ranked list of improvements ordered by return on investment with dependency rules and grant eligibility flagged. This gives you a concrete priority list rather than an overwhelming menu of options. Most households find that two or three improvements account for the majority of the available energy and cost benefit, and the sequencer identifies which those are for your specific property profile.
If you want a single calculator that models all improvement types with payback periods, a stacking model for combined savings, and a loan financing toggle, the energy upgrade payback calculator covers that in one tool. If you are primarily concerned about the affordability of current energy bills rather than improvement planning, the energy affordability calculator is a better starting point. If you are a landlord rather than an owner-occupier, the MEES portfolio planner is the most relevant starting point: it gives the compliance picture across your portfolio before any improvement planning begins.
Can I use these tools to apply for a grant or loan directly?
No. These calculators are planning tools only. They do not connect to any grant scheme, lender, or application process. ECO4 applications are made through energy suppliers (the scheme runs until December 2026 but remaining capacity is limited). The Warm Homes Local Grant is applied for through your local council. The Boiler Upgrade Scheme grant is applied for by the MCS-certified installer on your behalf as part of the installation process. For any of these schemes, the current eligibility criteria and application process are on GOV.UK (BUS), GOV.UK (ECO4), and GOV.UK (Warm Homes Local Grant).
If you want to explore a home improvement loan to fund works that are not covered by grants, the “Check eligibility” button throughout this site connects to Squared Money’s loan enquiry service. Squared Money is an introducer: it matches enquiries to regulated lenders but does not lend directly, set rates, or make lending decisions. Checking eligibility does not affect your credit score and does not commit you to borrowing anything.
Squaring Up
Energy improvement decisions involve a sequence of questions: what to prioritise, what each improvement costs and saves, how to time works relative to financial events, and how to fund the gap between improvement cost and any available grant. These tools cover that full sequence. The sequencer identifies priorities. The energy upgrade payback calculator models the financial case across all improvement types in one place, and the energy efficiency loan payback calculator models when the saving overtakes the interest on a loan for a single upgrade. The specialist calculators model heating, insulation, solar, battery, and EV charging decisions in detail. The financing and property tools address timing, funding, and the impact on mortgage and sale decisions.
None of these tools replaces professional advice for significant decisions. A heat pump installation, a remortgage, or a property transaction all involve enough financial complexity that a qualified professional with knowledge of your specific situation will produce better guidance than any calculator. The tools are designed to make those professional conversations more efficient and more productive by giving you the numbers before you walk through the door.
Continue your research
Guides, calculators, and comparators covering every aspect of home improvement finance Explore guides and toolsUpdate log: September 2026
September 2026
The all-in-one calculator is now referred to as the energy upgrade payback calculator, and the energy efficiency loan payback calculator is linked wherever it is mentioned, so the two tools are easier to tell apart. The loan payback card now describes the tool’s upgrade presets and grant quick-select. The Boiler Upgrade Scheme end date in the grant reference box has been updated.
July 2026
Government grant information was updated to reflect the current position as of July 2026. The Boiler Upgrade Scheme’s new £9,000 tier for off-gas-grid properties was added. ECO4’s December 2026 end date and limited remaining capacity were noted. The Warm Homes Local Grant was added as the successor to the Great British Insulation Scheme, which closed in March 2026. The BUS insulation precondition was corrected to reflect its removal in May 2024, with the recommendation to insulate before installing a heat pump reframed as best practice rather than a scheme eligibility condition. Direct links to GOV.UK application pages were added for all three current schemes.
The page was restructured to better serve its role as a planning hub. A “Find your starting point” routing section was added to help users identify the right tools for their situation. The energy efficiency payback calculator was added to the tools collection as a broad-scope entry point. The page title was updated to better distinguish this planning hub from the standalone calculator. An optimised title tag and meta description were added. A centralised grant reference box was introduced to consolidate scheme status in one place for easier maintenance.
All calculators and tools on this page are for illustrative and planning purposes only and do not constitute financial, mortgage, energy, or property advice. Figures are based on UK average data and will differ from actual costs, savings, and outcomes for any specific property or situation. Grant eligibility indications are based on published scheme criteria and do not account for all individual eligibility factors. Always verify current grant eligibility through the relevant scheme administrator on GOV.UK. Your home may be at risk if you do not keep up repayments on a secured loan.
