architects FROM LONDON Energy-efficient Renovations
Improve Comfort, Reduce Energy Use and Upgrade Your Home Properly
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Energy-efficient Renovations intro
Improve Comfort, Reduce Energy Use and Upgrade Your Home Properly
An energy-efficient renovation can improve how comfortable your home feels while reducing unnecessary heat loss and helping the building perform better overall.
The strongest projects do not treat insulation, heating, ventilation and windows as separate upgrades. They consider how the whole building works together.
At Tholos Architects, we design energy-efficient renovations around the existing property, its construction and your priorities so improvements are practical, coordinated and appropriate for the building.
An energy-efficient renovation can help you:
- Improve the internal layoutReduce heat loss
- Improve winter comfort
- Reduce overheating
- Improve insulation
- Upgrade windows and doors
- Improve airtightness
- Upgrade heating
- Improve ventilation
- Reduce draughts
- Lower unnecessary energy use
- Improve older homes sensitively
- Coordinate improvements with a wider renovation
The aim is to create a home that is more comfortable and efficient without introducing building-fabric problems through poorly coordinated upgrades.
Energy-efficient Renovations explained
What Is an Energy-efficient Renovation?
An energy-efficient renovation improves the performance of an existing home.
This may involve changes to:
- Roof
- Walls
- Floors
- Windows
- Doors
- Heating
- Hot water
- Ventilation
- Airtightness
- Controls
The exact combination depends on the property.
A modern cavity-wall house may need a very different strategy from a Victorian solid-wall property.
Start With the Existing Building
Before deciding what to upgrade, it is important to understand how the property is constructed.
This may include:
- Wall type
- Roof construction
- Floor construction
- Window condition
- Heating system
- Ventilation
- Existing insulation
- Damp or moisture issues
The best renovation strategy should respond to the actual building rather than apply the same specification to every home.
A Whole-house Approach
Energy improvements work best when they are considered together.
For example:
- Adding insulation changes heat loss
- Improving airtightness changes ventilation needs
- Replacing heating changes system demand
- New windows affect both heat loss and ventilation
- Extensions may alter the overall heating strategy
Looking at the house as one system can help avoid conflicting upgrades.
Roof and Loft Insulation
The roof can be a significant source of heat loss.
Depending on the property, insulation may be added:
- At ceiling level
- Between rafters
- Above rafters
- Within a converted loft
The correct solution depends on whether the loft is:
- Cold and unused
- Used for storage
- Converted into living accommodation
Ventilation and moisture control need to be considered alongside insulation.
Wall Insulation
Wall insulation can significantly improve thermal performance.
Possible approaches may include:
- Cavity-wall insulation
- Internal wall insulation
- External wall insulation
The correct option depends on:
- Wall construction
- Property age
- External appearance
- Internal finishes
- Moisture behaviour
- Planning constraints
Older solid-wall homes need particular care.
Internal Wall Insulation
Internal wall insulation can improve older solid-wall properties without changing the external appearance.
However, it can affect:
- Internal room sizes
- Window reveals
- Skirting
- Cornices
- Electrical fittings
- Moisture movement
The detailing needs to be carefully coordinated around the existing building fabric.
Energy-efficient Renovations
External Wall Insulation
External wall insulation can improve thermal performance while keeping internal floor area unchanged.
It may involve:
- ReInsulation boards
- New render
- Cladding systems
- Altered window reveals
- Roof and eaves detailing
Because it changes the external appearance, planning considerations may apply.
This can be especially important in:
- Conservation areas
- Listed buildings
- Character properties
Floor Insulation
Ground floors can also contribute to heat loss.
The appropriate solution depends on whether the property has:
- Suspended timber floors
- Solid floors
- Concrete floors
Possible improvements may include:
- Insulation beneath timber floors
- New insulated floor build-ups
- Insulation incorporated during renovation
Floor upgrades can often be easier to coordinate when the property is already undergoing substantial refurbishment.
Windows
Windows influence:
- Heat loss
- Draughts
- Daylight
- Ventilation
- Appearance
Possible improvements may include:
- Repairing existing windows
- Draught proofing
- Secondary glazing
- Double glazing
- Replacement windows
The right solution depends on the building.
Older and historic properties may benefit from repair and secondary glazing rather than complete replacement.
Doors
External doors can also contribute to heat loss and draughts.
Improvements may include:
- Better seals
- Repair
- Improved glazing
- Replacement
- Upgraded thresholds
The design should balance thermal performance with appearance and access.
Airtightness
Reducing uncontrolled air leakage can improve comfort and reduce heat loss.
Common leakage points include:
- Windows
- Doors
- Floor junctions
- Service penetrations
- Loft hatches
- Chimneys
- aps around pipework
However, improving airtightness increases the importance of planned ventilation.
A house should not simply be sealed without considering how fresh air will be provided.
Ventilation
Ventilation is a critical part of energy-efficient renovation.
As homes become better insulated and more airtight, moisture and indoor air quality need to be managed properly.
Ventilation may include:
- Trickle vents
- Extract fans
- Passive ventilation
- Mechanical ventilation
- Mechanical ventilation with heat recovery
The correct system depends on:
- Property size
- Airtightness
- Layout
- Existing construction
- Extent of renovation
Energy-efficient Renovations
Avoid Condensation and Mould
Energy improvements should reduce problems rather than create them.
Poorly designed insulation or airtightness measures can sometimes contribute to:
- Condensation
- Mould
- Trapped moisture
A good renovation strategy should consider:
- Moisture movement
- Thermal bridges
- Ventilation
- Existing damp
- Material compatibility
This is particularly important in older buildings.
Thermal Bridging
Thermal bridges occur where heat can bypass insulation through parts of the construction.
Common locations include:
- Window reveals
- Floor edges
- Roof junctions
- Wall junctions
- Structural elements
Poor detailing can reduce the effectiveness of otherwise good insulation.
Energy-efficient renovation therefore depends on both the specification and the junction details.
Heating Upgrades
Once heat loss has been reduced, the heating system can be assessed properly.
Possible upgrades include:
- New boiler
- Heat pump
- Underfloor heating
- New radiators
- Zoned heating
- Improved controls
A more efficient building may require less heating capacity than before.
Heat Pumps
Heat pumps can be suitable for some renovation projects.
Their performance can depend on factors such as:
- Heat loss
- Insulation
- Radiator sizes
- Underfloor heating
- Flow temperatures
- Hot water requirements
Improving the fabric of the building first can help create better conditions for a lower-temperature heating system.
Underfloor Heating
Underfloor heating may be considered during more substantial renovations.
It can work particularly well where:
- Floors are already being replaced
- Extensions are being constructed
- Lower-temperature heating is planned
The floor construction and insulation need to be coordinated with the heating design.
Heating Controls
Improved controls can help reduce unnecessary energy use.
Possible upgrades include:
- Programmable thermostats
- Zoned heating
- Smart controls
- Thermostatic radiator valves
Controls should be simple enough to use effectively.
Hot Water
Energy-efficient renovation should also consider hot water.
The project may assess:
- Boiler system
- Cylinder
- Heat pump
- Pipe insulation
- Water storage
- Controls
The right approach depends on household demand and the wider heating system.
Energy-efficient Renovations
Renewable Energy
Some projects may include renewable technologies such as:
- Solar photovoltaic panels
- Battery storage
- Solar thermal systems
- Heat pumps
These should be considered as part of the wider energy strategy rather than added independently of the building design.
Solar Panels
Solar PV can reduce electricity purchased from the grid.
Their suitability depends on:
- Roof orientation
- Shading
- Roof condition
- Available area
- Planning constraints
The roof should generally be assessed before installation, particularly where renovation or roof replacement is already planned.
Energy-efficient Renovations
Improve Energy Efficiency During a House Renovation
A renovation is often the best time to improve energy performance because floors, walls and ceilings may already be accessible.
This can make it easier to coordinate:
- Insulation
- Heating
- Electrical upgrades
- Ventilation
- Windows
- Airtightness
Energy-efficient Victorian Renovations
Victorian homes can often be made significantly more comfortable, but they require an appropriate approach.
They may have:
- Solid walls
- Suspended timber floors
- Original windows
- Chimneys
- Traditional materials
Possible improvements include:
- Loft insulation
- Floor insulation
- Draught reduction
- Window repair
- Secondary glazing
- Sensitive wall insulation
- Heating upgrades
Energy-efficient Period-property Renovations
Older homes often need a different approach from modern houses.
The renovation strategy should consider:
- Breathable construction
- Solid walls
- Original timber
- Lime-based materials
- Moisture movement
Modern materials should not automatically be applied without considering how they interact with the existing building.
Energy Efficiency in Listed Buildings
Listed buildings can often be improved, but changes need to respect historic significance.
Possible measures may include:
- Roof insulation
- Floor insulation
- Draught reduction
- Secondary glazing
- Heating upgrades
- Improved controls
More intrusive changes may require additional consideration or consent.
Energy Efficiency in Conservation Areas
Conservation-area properties can also be upgraded.
However, external changes may be more sensitive.
This can affect:
- Replacement windows
- External wall insulation
- Solar panels
- Roof alterations
- External plant
Energy-efficient Renovations
Extensions and Energy Performance
If you are extending the house, the project provides an opportunity to consider the existing building and new extension together.
The extension may include:
- High-performance insulation
- Efficient glazing
- Improved airtightness
- Modern heating
- Better ventilation
The existing house can then be upgraded alongside it.
Loft Conversions and Energy Performance
A loft conversion changes the thermal envelope of the house.
The new design needs to coordinate:
- Roof insulation
- Ventilation
- Heating
- Windows
- Airtightness
This can also be an opportunity to improve neighbouring areas of the roof.
Structural Work
Energy-efficient renovation can sometimes involve structural alterations.
These may include:
- Floor replacement
- Roof work
- New openings
- Extension structures
- - Support for altered walls
Where structural work is required, it should be coordinated with insulation and thermal detailing rather than designed separately.
Building Regulations
Energy-efficiency improvements may interact with Building Regulations requirements.
Depending on the project, this may involve:
- Thermal performance
- Ventilation
- Heating systems
- Windows
- Structural alterations
- Extensions
- Renovated thermal elements
The exact requirements depend on the scope of work.
Planning Permission
Many internal energy-efficiency improvements do not require planning permission.
Planning considerations may become relevant where work changes the external appearance, for example:
- External wall insulation
- Window alterations
- Solar panels
- External heat-pump equipment
- Roof alterations
Restrictions may also apply to:
- Listed buildings
- Conservation areas
Energy-efficient Renovations
Energy-efficient Renovation Process
1. Assess the Existing Property
We begin by considering:
- Building age
- Construction type
- Existing insulation
- Windows
- Heating
- Ventilation
- Areas of heat loss
2. Identify the Priorities
We discuss:
- Comfort problems
- Energy use
- Planned renovation work
- Budget
- Long-term plans
3. Develop the Fabric Strategy
We consider improvements to:
- Roof
- Walls
- Floors
- Windows
- Doors
- Airtightness
4. Coordinate Ventilation
We consider how improved airtightness and insulation affect:
- Fresh air
- Moisture
- Extraction
- Indoor air quality
5. Review Heating and Hot Water
We assess possible improvements to:
- Heating system
- Controls
- Emitters
- Hot water
6. Integrate the Work With the Renovation
Where the property is also being remodelled, extended or refurbished, energy upgrades are coordinated with the wider design.
7. Check Approvals
Where required, this may include:
- Planning permission
- Building Regulations
- Conservation requirements
- Listed Building Consent
8. Develop the Technical Design
Detailed drawings can then coordinate:
- Insulation
- Junctions
- Ventilation
- Heating
- Existing construction
- New work
9. Prepare for Construction
The project can then move forward with a coordinated specification rather than a series of disconnected energy upgrades.
Client experience
"
Lorem ipsum dolor sit amet, consectetur adipiscing elit. We had a vision for our home but no idea how to realise it. Tholos Interiors took complete ownership of the project — every detail was considered, every decision explained. The result exceeded everything we had imagined.
– Lawrence Ipsum, Homeowner · London –
Frequently Asked Questions
What is the best way to make an old house more energy efficient?
There is no single measure that works for every house.
The best approach usually combines appropriate insulation, draught reduction, ventilation and heating improvements based on the property’s construction.
Do I need to improve ventilation when adding insulation?
Potentially, yes.
As uncontrolled air leakage is reduced, planned ventilation becomes increasingly important.
Can I install a heat pump in an older house?
Potentially.
The building’s heat loss, insulation, heating emitters and hot-water requirements should be assessed as part of the system design.
Do energy-efficiency improvements need planning permission?
Many do not, but external changes and works to listed or conservation-area properties may require planning or other consent.
Make Your Home More Comfortable as Well as More Efficient
Energy-efficient renovation is not simply about adding insulation or replacing a boiler.
The best results come from understanding how the entire building works and coordinating the fabric, heating, ventilation and planned renovation work as one project.
At Tholos Architects, we can help you develop an energy-efficient renovation strategy that improves comfort and performance while responding properly to the character and construction of your home.
Disclaimer
This article is part of a series created by our dynamic marketing team for informational purposes only. While we strive to review all content thoroughly, occasional oversights may occur, even after publication. Therefore, we cannot accept liability for any interpretations or use of the information provided. For the most up-to-date information or to report any discrepancies, please contact us at hello@tholos-architects.com.
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