Whether you've added an extension, upgraded insulation, installed a new boiler, fitted solar panels, or converted your loft, your electricity and gas usage is unlikely to match what it was before.
In this guide, we explain from first principles:
Why home renovations affect energy consumption
When you should compare energy suppliers
How renovations change your ideal tariff
What to review before switching
Common mistakes homeowners make
If you want to avoid overpaying after upgrading your property, this guide will help you make a data-driven decision.
Why Renovations Change Your Energy Profile
Energy costs are driven by one simple formula:
When you renovate your home, you often change your annual usage — sometimes significantly.
Renovations typically fall into two broad categories:
1. Energy-Reducing Improvements
- Loft insulation upgrades
- Cavity wall insulation
- Triple glazing
- New energy-efficient boilers
- Smart thermostats
- Air source heat pumps
- Solar panels
These improvements usually reduce gas or electricity consumption.
2. Energy-Increasing Changes
- Extensions
- Loft conversions
- Garage conversions
- Underfloor heating installation
- Electric vehicle (EV) chargers
- Home office additions
- Additional bathrooms
These changes often increase electricity or gas demand.
In both cases, your previous tariff may no longer be the most cost-effective.
When Should You Compare Energy Prices After Renovation?
At Utility King, we recommend comparing energy prices if:
You have significantly changed your heating system
You've installed solar panels or battery storage
You've added electric heating
Your household size has increased
You've installed an EV charger
You've expanded your property size
Even improvements that reduce usage may shift the balance between standing charge and unit rate importance.
Renovation is a financial reset point — energy comparison should follow.
Renovation Scenarios
Scenario 1: Improved Energy Efficiency
If your renovation reduced energy usage, your priorities may shift.
Lower-usage households are more affected by standing charges because:
- You pay the standing charge every day
- It becomes a larger proportion of your total bill
In this case, comparing energy suppliers with lower standing charges may provide better long-term savings.
Your previous high-consumption tariff may no longer be optimal.
Scenario 2: Increased Electricity Demand
If you've installed:
- An air source heat pump
- Underfloor heating
- Electric radiators
- An EV charger
Your electricity consumption may rise significantly.
In this scenario, the unit rate per kWh becomes critical. Even small differences in electricity rates can scale dramatically with high usage.
You may also benefit from:
- Time-of-use tariffs
- EV-specific energy tariffs
- Economy 7 or off-peak pricing
Comparing energy prices strategically becomes essential.
Scenario 3: Solar Panel Installation
If you've installed solar panels, your energy setup changes fundamentally.
You now need to consider:
- Import tariffs (what you pay)
- Export tariffs (what you earn)
The Smart Export Guarantee (SEG) allows you to receive payment for excess electricity exported to the grid.
When comparing energy deals after solar installation, evaluate:
- Electricity unit rate
- Export rate
- Standing charge
- Billing transparency
A slightly higher import tariff may be worthwhile if export payments are significantly better.
Scenario 4: Switching From Gas to Electric Heating
If you've removed a gas boiler and installed:
- A heat pump
- Electric heating
- Hybrid systems
You may become electricity-dominant.
This changes the cost structure completely. Gas usage may decrease or disappear entirely. Your comparison strategy must adjust accordingly. Electricity unit rates matter more than before.
How to Compare Energy Prices After Renovation
At Utility King, we recommend a structured review process.
Monitor Post-Renovation Usage
Wait at least 2–3 months after renovation to:
Gather updated meter readings
Identify new consumption patterns
Understand seasonal impact
Real data beats assumptions.
Calculate Your New Estimated Annual Usage
If you have smart meter access, use:
Monthly usage reports
Peak vs off-peak data
Electricity vs gas balance
Accurate data makes comparison reliable.
Compare Total Annual Cost
When reviewing new tariffs, focus on:
Unit rate
Standing charge
Estimated annual cost
Payment method differences
Do not rely solely on headline rates.
Review Tariff Type
Choose between:
Fixed Energy Tariffs — Price stability, budget predictability
Variable Tariffs — Flexibility, exposure to market changes
If your energy usage has increased significantly, locking in a competitive fixed rate may reduce risk.
Common Mistakes After Renovation
Staying on the Same Tariff Automatically
Your previous tariff was designed for a different energy profile.
Ignoring Standing Charges After Efficiency Upgrades
Low-usage homes must watch daily charges closely.
Not Considering Time-of-Use Tariffs After EV Installation
EV charging overnight can significantly benefit from off-peak pricing.
Forgetting to Register for Export Payments
Solar panel owners must register for Smart Export Guarantee tariffs to earn properly.
Is Switching Energy Supplier Safe After Renovation?
Yes.
Switching energy supplier:
Does not affect your new systems
Does not interfere with installations
Does not disrupt supply
Is fully regulated
Your infrastructure remains unchanged. Only your billing provider changes.
Utility King's Perspective
At Utility King, we see renovation as a financial turning point.
You've invested in improving your property — your energy tariff should now reflect that change.
Energy comparison after renovation ensures:
You're not paying outdated rates
Your tariff matches your new consumption profile
You maximise savings from efficiency upgrades
You benefit from export tariffs where applicable
Renovation changes your home. Your energy strategy should change too.
Frequently Asked Questions
Should I compare after solar installation?
Yes. You should review both import tariffs and Smart Export Guarantee rates.
Does adding an extension increase bills?
Often yes, due to increased heating and electricity demand.
Is a fixed tariff better after renovation?
It depends on your new usage profile and market conditions.
Do efficiency upgrades reduce need to switch?
Not necessarily. Lower usage may shift which tariff is most cost-effective.
Should I wait before switching?
It's wise to gather some usage data first, unless you're on an expensive standard variable tariff.
Can I switch if I've installed a heat pump?
Yes. Switching does not affect your heating system.